diff --git a/kenwood/elecraft.c b/kenwood/elecraft.c
index 6884bc1f4..d1d6eacd9 100644
--- a/kenwood/elecraft.c
+++ b/kenwood/elecraft.c
@@ -289,10 +289,9 @@ int elecraft_get_firmware_revision_level(RIG *rig, const char *cmd,
 	int err;
 	char *bufptr;
 	char buf[KENWOOD_MAX_BUF_LEN];
-	size_t size = KENWOOD_MAX_BUF_LEN;
 
 	/* Get the actual firmware revision number. */
-	err = kenwood_transaction(rig, cmd, buf, &size);
+	err = kenwood_transaction(rig, cmd, buf, sizeof (buf));
 
 	if (err != RIG_OK) {
 		rig_debug(RIG_DEBUG_VERBOSE, "%s: Cannot get firmware revision level\n", __func__);
diff --git a/kenwood/kenwood.c b/kenwood/kenwood.c
index f3dcbe416..c1528982b 100644
--- a/kenwood/kenwood.c
+++ b/kenwood/kenwood.c
@@ -184,16 +184,15 @@ const struct confparams kenwood_cfg_params[] = {
  *        is needed and will return with RIG_OK after command was sent.
  * datasize: in: Size of buffer. It is the caller's responsibily to provide
  *         a large enough buffer for all possible replies for a command.
- *      out: Location where to store number of bytes read.
  *
  * returns:
- *   RIG_OK -   if no error occured.
+ *   RIG_OK -   if no error occurred.
  *   RIG_EIO -    if an I/O error occured while sending/receiving data.
  *   RIG_ETIMEOUT - if timeout expires without any characters received.
  *   RIG_REJECTED - if a negative acknowledge was received or command not
  *          recognized by rig.
  */
-int kenwood_transaction(RIG *rig, const char *cmdstr, char *data, size_t *datasize)
+int kenwood_transaction(RIG *rig, const char *cmdstr, char *data, size_t datasize)
 {
   char buffer[KENWOOD_MAX_BUF_LEN]; /* use our own buffer since
                                        verification may need a longer
@@ -201,7 +200,7 @@ int kenwood_transaction(RIG *rig, const char *cmdstr, char *data, size_t *datasi
 
   rig_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
 
-  if (!rig || !datasize || !cmdstr)
+  if (!rig || (!cmdstr && !datasize) || datasize < 0 || (datasize && !data))
     return -RIG_EINVAL;
 
   struct kenwood_priv_caps *caps = kenwood_caps(rig);
@@ -211,7 +210,6 @@ int kenwood_transaction(RIG *rig, const char *cmdstr, char *data, size_t *datasi
   char *cmd;
   int len;
   int retry_read = 0;
-  int reply_expected = !cmdstr || (data && *datasize > 0);
   static char const std_verify[] = "ID;"; /* command we can always
                                              send to any rig even when
                                              the rig is busy */
@@ -256,7 +254,7 @@ int kenwood_transaction(RIG *rig, const char *cmdstr, char *data, size_t *datasi
         goto transaction_quit;
     }
 
-  if (!reply_expected) {
+  if (!datasize) {
     rig->state.hold_decode = 0;
 
     /* no reply expected so we need to write a command that always
@@ -267,7 +265,7 @@ int kenwood_transaction(RIG *rig, const char *cmdstr, char *data, size_t *datasi
     }
   }
 
-  len = min (reply_expected ? *datasize : strlen (verify) + 5, KENWOOD_MAX_BUF_LEN);
+  len = min (datasize ? datasize : strlen (verify) + 5, KENWOOD_MAX_BUF_LEN);
   retval = read_string(&rs->rigport, buffer, len, cmdtrm, strlen(cmdtrm));
   if (retval < 0) {
     if (retry_read++ < rig->caps->retry)
@@ -337,7 +335,7 @@ int kenwood_transaction(RIG *rig, const char *cmdstr, char *data, size_t *datasi
    * single character commands we only check the first character in
    * that case.
    */
-  if (reply_expected)
+  if (datasize)
     {
       if (cmdstr && (buffer[0] != cmdstr[0] || (cmdstr[1] && buffer[1] != cmdstr[1])))
         {
@@ -360,9 +358,9 @@ int kenwood_transaction(RIG *rig, const char *cmdstr, char *data, size_t *datasi
         {
           /* move the result excluding the command terminator into the
              caller buffer */
-          *datasize = min (*datasize, retval) - 1;
-          strncpy (data, buffer, *datasize);
-          data[*datasize] = '\0';
+          len = min (datasize, retval) - 1;
+          strncpy (data, buffer, len);
+          data[len] = '\0';
         }
     }
   else
@@ -426,12 +424,12 @@ int kenwood_safe_transaction(RIG *rig, const char *cmd, char *buf,
 
   do
     {
-      size_t length = buf_size;
-      err = kenwood_transaction(rig, cmd, buf, &length);
+      err = kenwood_transaction(rig, cmd, buf, buf_size);
       if (err != RIG_OK)        /* return immediately on error as any
                                    retries handled at lower level */
         return err;
 
+      size_t length = strlen (buf);
       if (length != expected) /* worth retrying as some rigs
                                    occasionally send short results */
         {
@@ -531,31 +529,27 @@ int kenwood_open(RIG *rig)
   if (RIG_MODEL_TS590S == rig->caps->rig_model)
     {
       /* we need the firmware version for these rigs to deal with f/w defects */
-      char buffer[KENWOOD_MAX_BUF_LEN];
-      static char fw_version[5];
-      size_t size = KENWOOD_MAX_BUF_LEN;
+      static char fw_version[7];
       struct kenwood_priv_data * priv = rig->state.priv;
 
-      err = kenwood_transaction (rig, "FV", buffer, &size);
+      err = kenwood_transaction (rig, "FV", fw_version, sizeof (fw_version));
       if (RIG_OK != err)
         {
-    rig_debug (RIG_DEBUG_ERR, "%s: cannot get f/w version\n", __func__);
-    return err;
+          rig_debug (RIG_DEBUG_ERR, "%s: cannot get f/w version\n", __func__);
+          return err;
         }
-      /* store the data between "FV" and ";" which should be a
-         f/w version string of the form n.n e.g. 1.07 */
-      priv->fw_rev = strncpy (fw_version, &buffer[2], size - 3);
-      char * dot_pos = strchr (buffer, '.');
+      /* store the data  after the "FV" which should be  a f/w version
+         string of the form n.n e.g. 1.07 */
+      priv->fw_rev = &fw_version[2];
+      char * dot_pos = strchr (fw_version, '.');
       if (dot_pos)
         {
-    *dot_pos = '\0';
-    buffer[size - 1] = '\0';
-    priv->fw_rev_uint = atoi (&buffer[2]) * 100 + atoi (dot_pos + 1);
+          priv->fw_rev_uint = atoi (&fw_version[2]) * 100 + atoi (dot_pos + 1);
         }
       else
         {
-    rig_debug (RIG_DEBUG_ERR, "%s: cannot get f/w version\n", __func__);
-    return -RIG_EPROTO;
+          rig_debug (RIG_DEBUG_ERR, "%s: cannot get f/w version\n", __func__);
+          return -RIG_EPROTO;
         }
       rig_debug (RIG_DEBUG_TRACE, "%s: found f/w version %s\n", __func__, priv->fw_rev);
     }
@@ -626,9 +620,7 @@ int kenwood_get_id(RIG *rig, char *buf)
   if (!rig)
     return -RIG_EINVAL;
 
-  size_t size = KENWOOD_MAX_BUF_LEN;
-
-  return kenwood_transaction(rig, "ID", buf, &size);
+  return kenwood_transaction(rig, "ID", buf, KENWOOD_MAX_BUF_LEN);
 }
 
 
@@ -1510,11 +1502,10 @@ int kenwood_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
   if (!rig || !val)
     return -RIG_EINVAL;
 
-  char lvlbuf[50];
+  char lvlbuf[KENWOOD_MAX_BUF_LEN];
   int retval;
   int lvl;
   int i, ret, agclevel;
-  size_t lvl_len;
 
   switch (level) {
   case RIG_LEVEL_RAWSTR:
@@ -1615,16 +1606,14 @@ int kenwood_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
     return ret;
 
   case RIG_LEVEL_SLOPE_LOW:
-    lvl_len = 50;
-    retval = kenwood_transaction (rig, "SL", lvlbuf, &lvl_len);
+    retval = kenwood_transaction (rig, "SL", lvlbuf, sizeof (lvlbuf));
     if (retval != RIG_OK)
       return retval;
     val->i=atoi(&lvlbuf[2]);
     break;
 
   case RIG_LEVEL_SLOPE_HIGH:
-    lvl_len = 50;
-    retval = kenwood_transaction (rig, "SH", lvlbuf, &lvl_len);
+    retval = kenwood_transaction (rig, "SH", lvlbuf, sizeof (lvlbuf));
     if (retval != RIG_OK)
       return retval;
     val->i=atoi(&lvlbuf[2]);
diff --git a/kenwood/kenwood.h b/kenwood/kenwood.h
index 26b7f6b36..99232c639 100644
--- a/kenwood/kenwood.h
+++ b/kenwood/kenwood.h
@@ -88,8 +88,7 @@ extern rmode_t kenwood_mode_table[KENWOOD_MODE_TABLE_MAX];
 extern const tone_t kenwood38_ctcss_list[];
 extern const tone_t kenwood42_ctcss_list[];
 
-int kenwood_transaction(RIG *rig, const char *cmd, char *data,
-        size_t *data_len);
+int kenwood_transaction(RIG *rig, const char *cmd, char *data, size_t data_len);
 int kenwood_safe_transaction(RIG *rig, const char *cmd, char *buf,
         size_t buf_size, size_t expected);
 
diff --git a/kenwood/th.c b/kenwood/th.c
index 9beb8aadd..f7a9163ef 100644
--- a/kenwood/th.c
+++ b/kenwood/th.c
@@ -52,16 +52,16 @@ th_decode_event (RIG *rig)
 {
 	char asyncbuf[128];
 	int retval;
-	size_t async_len=128;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
-	retval = kenwood_transaction(rig, NULL, asyncbuf, &async_len);
+	retval = kenwood_transaction(rig, NULL, asyncbuf, sizeof (asyncbuf));
 	if (retval != RIG_OK)
 		return retval;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: Decoding message\n", __func__);
 
+	size_t async_len = strlen (asyncbuf);
 	if (async_len> 3 && asyncbuf[0] == 'B' && asyncbuf[1] == 'U' && asyncbuf[2] == 'F') {
 
 		vfo_t vfo;
@@ -410,17 +410,17 @@ int
 th_get_vfo_char(RIG *rig, vfo_t *vfo, char *vfoch)
 {
 	char cmdbuf[10], buf[10], vfoc;
-	size_t buf_size=10;
 	int retval;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
 	/* Get VFO band */
 
-	retval = kenwood_transaction(rig, "BC", buf, &buf_size);
+	retval = kenwood_transaction(rig, "BC", buf, sizeof (buf));
 	if (retval != RIG_OK)
 		return retval;
-	switch (buf_size) {
+	size_t length = strlen (buf);
+	switch (length) {
 	case 4: /*original case BC 0*/
 	  vfoc = buf[3];
 	  break;
@@ -433,7 +433,7 @@ th_get_vfo_char(RIG *rig, vfo_t *vfo, char *vfoch)
 	  }
 	  break;
 	default:
-	  rig_debug(RIG_DEBUG_ERR, "%s: Unexpected answer length '%c'\n", __func__, buf_size);
+	  rig_debug(RIG_DEBUG_ERR, "%s: Unexpected answer length '%c'\n", __func__, length);
 	  return -RIG_EPROTO;
 	  break;
 	}
@@ -512,8 +512,6 @@ int tm_set_vfo_bc2 (RIG *rig, vfo_t vfo)
     char vfobuf[16], ackbuf[16];
     int vfonum, txvfonum, vfomode=0;
     int retval;
-    size_t ack_len;
-
 
     rig_debug(RIG_DEBUG_TRACE, "%s: called %s\n", __func__, rig_strvfo(vfo));
 
@@ -534,8 +532,7 @@ int tm_set_vfo_bc2 (RIG *rig, vfo_t vfo)
         case RIG_VFO_MEM:
             /* get current band */
             sprintf(vfobuf, "BC");
-            ack_len=16;
-            retval = kenwood_transaction(rig, vfobuf, ackbuf, &ack_len);
+            retval = kenwood_transaction(rig, vfobuf, ackbuf, sizeof (ackbuf));
             if (retval != RIG_OK)
                 return retval;
             txvfonum = vfonum = ackbuf[3]-'0';
@@ -664,20 +661,19 @@ th_get_trn(RIG *rig, int *trn)
 {
 	char buf[ACKBUF_LEN];
 	int retval;
-	size_t ack_len=ACKBUF_LEN;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
-	retval = kenwood_transaction(rig, "AI", buf, &ack_len);
+	retval = kenwood_transaction(rig, "AI", buf, sizeof (buf));
 	if (retval != RIG_OK)
 		return retval;
 
-	if (ack_len != 3 ) {
+	if (strlen (buf) != 3 ) {
 		rig_debug(RIG_DEBUG_ERR, "%s: Unexpected reply '%s'\n", __func__, buf);
 		return -RIG_ERJCTED;
 	}
 
-	*trn = (buf[3] != '0') ? RIG_TRN_RIG : RIG_TRN_OFF;
+	*trn = (buf[2] != '0') ? RIG_TRN_RIG : RIG_TRN_OFF;
 
 	return RIG_OK;
 }
@@ -926,7 +922,6 @@ th_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 	char vch, buf[10], ackbuf[20];
 	int retval, v, l;
 
-	size_t ack_len = sizeof(ackbuf);
 	vfo_t tvfo;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
@@ -949,7 +944,7 @@ th_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 		sprintf(buf, "SM %c", vch);
 
 		// XXX use kenwood_safe_transaction
-		retval = kenwood_transaction(rig, buf, ackbuf, &ack_len);
+		retval = kenwood_transaction(rig, buf, ackbuf, sizeof (ackbuf));
 		if (retval != RIG_OK)
 			return retval;
 
@@ -981,7 +976,7 @@ th_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 
 	case RIG_LEVEL_AF:
 		sprintf(buf, "AG %c", vch);
-		retval = kenwood_transaction(rig, buf, ackbuf, &ack_len);
+		retval = kenwood_transaction(rig, buf, ackbuf, sizeof (ackbuf));
 		if (retval != RIG_OK)
 			return retval;
 
@@ -998,7 +993,7 @@ th_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 
 	case RIG_LEVEL_RFPOWER:
 		sprintf(buf, "PC %c",vch);
-		retval = kenwood_transaction(rig, buf, ackbuf, &ack_len);
+		retval = kenwood_transaction(rig, buf, ackbuf, sizeof (ackbuf));
 		if (retval != RIG_OK)
 			return retval;
 
@@ -1135,9 +1130,8 @@ int
 th_set_ctcss_tone(RIG *rig, vfo_t vfo, tone_t tone)
 {
 	const struct rig_caps *caps;
-	char tonebuf[16],ackbuf[ACKBUF_LEN];
+	char tonebuf[16];
 	int i, retval;
-	size_t ack_len;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
@@ -1153,8 +1147,7 @@ th_set_ctcss_tone(RIG *rig, vfo_t vfo, tone_t tone)
 
 	i += (i == 0) ? 1 : 2;  /* Correct for TH-D7A index anomally */
 	sprintf(tonebuf, "TN %02d", i);
-	ack_len = ACKBUF_LEN;
-	retval = kenwood_transaction(rig, tonebuf, ackbuf, &ack_len);
+	retval = kenwood_transaction(rig, tonebuf, NULL, 0);
 	if (retval != RIG_OK)
 		return retval;
 
@@ -1171,14 +1164,13 @@ th_get_ctcss_tone(RIG *rig, vfo_t vfo, tone_t *tone)
 	struct rig_caps *caps;
 	char buf[ACKBUF_LEN];
 	int retval;
-	size_t ack_len=ACKBUF_LEN;
 	unsigned int tone_idx;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
 	caps = rig->caps;
 
-	retval = kenwood_transaction(rig, "TN", buf, &ack_len);
+	retval = kenwood_transaction(rig, "TN", buf, sizeof (buf));
 	if (retval != RIG_OK)
 		return retval;
 
@@ -1209,9 +1201,8 @@ int
 th_set_ctcss_sql(RIG *rig, vfo_t vfo, tone_t tone)
 {
 	const struct rig_caps *caps;
-	char tonebuf[16],ackbuf[ACKBUF_LEN];
+	char tonebuf[16];
 	int i, retval;
-	size_t ack_len;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
@@ -1227,8 +1218,7 @@ th_set_ctcss_sql(RIG *rig, vfo_t vfo, tone_t tone)
 
 	i += (i == 0) ? 1 : 2;  /* Correct for TH-D7A index anomally */
 	sprintf(tonebuf, "CTN %02d", i);
-	ack_len = ACKBUF_LEN;
-	retval = kenwood_transaction(rig, tonebuf, ackbuf, &ack_len);
+	retval = kenwood_transaction(rig, tonebuf, NULL, 0);
 	if (retval != RIG_OK)
 		return retval;
 
@@ -1245,14 +1235,13 @@ th_get_ctcss_sql(RIG *rig, vfo_t vfo, tone_t *tone)
 	struct rig_caps *caps;
 	char buf[ACKBUF_LEN];
 	int retval;
-	size_t ack_len=ACKBUF_LEN;
 	unsigned int tone_idx;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
 	caps = rig->caps;
 
-	retval = kenwood_transaction(rig, "CTN", buf, &ack_len);
+	retval = kenwood_transaction(rig, "CTN", buf, sizeof (buf));
 	if (retval != RIG_OK)
 		return retval;
 
@@ -1328,14 +1317,13 @@ th_get_dcs_sql(RIG *rig, vfo_t vfo, tone_t *code)
 	struct rig_caps *caps;
 	char buf[ACKBUF_LEN];
 	int retval;
-	size_t ack_len=ACKBUF_LEN;
 	unsigned int code_idx;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
 	caps = rig->caps;
 
-	retval = kenwood_transaction(rig, "DCS", buf, &ack_len);
+	retval = kenwood_transaction(rig, "DCS", buf, sizeof (buf));
 	if (retval != RIG_OK)
 		return retval;
 
@@ -1351,8 +1339,7 @@ th_get_dcs_sql(RIG *rig, vfo_t vfo, tone_t *code)
 		return RIG_OK;
     }
 
-	ack_len=ACKBUF_LEN;
-	retval = kenwood_transaction(rig, "DCSN", buf, &ack_len);
+	retval = kenwood_transaction(rig, "DCSN", buf, sizeof (buf));
 	if (retval != RIG_OK)
 		return retval;
 
@@ -1380,16 +1367,14 @@ th_get_info(RIG *rig)
 {
 	static char firmbuf[50];
 	int retval;
-	size_t firm_len=50;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
-	memset(firmbuf, 0, sizeof(firmbuf));
-
-	retval = kenwood_transaction(rig, "ID", firmbuf, &firm_len);
+	retval = kenwood_transaction(rig, "ID", firmbuf, sizeof (firmbuf));
 	if (retval != RIG_OK)
 		return NULL;
 
+	size_t firm_len = strlen (firmbuf);
 	if (firm_len < 3) {
 		rig_debug(RIG_DEBUG_ERR, "%s: unexpected reply '%s', len=%d\n",
 			   __func__, firmbuf, firm_len);
@@ -1577,7 +1562,6 @@ int th_get_channel(RIG *rig, channel_t *chan)
 {
 	char membuf[64],ackbuf[ACKBUF_LEN];
 	int retval;
-	size_t ack_len;
 	freq_t freq,offset;
 	char req[16],scf[128];
 	int step, shift, rev, tone, ctcss, tonefq, ctcssfq, dcs, dcscode, mode, lockout;
@@ -1657,9 +1641,8 @@ int th_get_channel(RIG *rig, channel_t *chan)
 	}
 
 	sprintf(membuf, "%s",req);
-	ack_len=ACKBUF_LEN;
 
-	retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+	retval = kenwood_transaction(rig, membuf, ackbuf, sizeof (ackbuf));
 	if (retval != RIG_OK)
 		return retval;
 
@@ -1761,8 +1744,7 @@ int th_get_channel(RIG *rig, channel_t *chan)
 		/* split ? */
 		req[3+strlen(mr_extra)]='1';
 		sprintf(membuf, "%s",req);
-		ack_len=ACKBUF_LEN;
-		retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+		retval = kenwood_transaction(rig, membuf, ackbuf, sizeof (ackbuf));
 		if (retval == RIG_OK) {
 			strcpy(scf,req);
 			strcat(scf, ",%"SCNfreq",%x");
@@ -1778,13 +1760,13 @@ int th_get_channel(RIG *rig, channel_t *chan)
 			sprintf(membuf, "MNA %sI-%01d",mr_extra,channel_num);
 		else
 			sprintf(membuf, "MNA %s%03d",mr_extra,channel_num);
-		ack_len=ACKBUF_LEN;
 
 		/* Get memory name */
-		retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+		retval = kenwood_transaction(rig, membuf, ackbuf, sizeof (ackbuf));
 		if (retval != RIG_OK)
 			return retval;
 
+		size_t ack_len = strlen (ackbuf);
 		if (ack_len > rig->caps->chan_desc_sz)
 			ack_len = rig->caps->chan_desc_sz;
 
@@ -1810,9 +1792,8 @@ static int find_tone_index(const tone_t *tone_list, tone_t tone)
 /* --------------------------------------------------------------------- */
 int th_set_channel(RIG *rig, const channel_t *chan)
 {
-	char membuf[ACKBUF_LEN],ackbuf[ACKBUF_LEN];
+	char membuf[ACKBUF_LEN];
 	int retval;
-	size_t ack_len;
 	char req[64];
 	char lockoutstr[8];
 	int channel_num, step, shift, rev, tone, ctcss, tonefq, ctcssfq, dcs, dcscode, mode, lockout;
@@ -1972,9 +1953,7 @@ int th_set_channel(RIG *rig, const channel_t *chan)
 			);
 	}
 
-	ack_len = ACKBUF_LEN;
-
-	retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+	retval = kenwood_transaction(rig, membuf, NULL, 0);
 	if (retval != RIG_OK)
 		return retval;
 
@@ -1986,23 +1965,20 @@ int th_set_channel(RIG *rig, const channel_t *chan)
 		req[3+strlen(mr_extra)]='1';
 
 		sprintf(membuf, "%s,%011"PRIll",%X", req,(int64_t)chan->tx_freq, step);
-		ack_len=ACKBUF_LEN;
-
-		retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+		retval = kenwood_transaction(rig, membuf, NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 	}
 
 	if (channel_desc) {
 		/* Memory name */
-		ack_len=ACKBUF_LEN;
 		/* TODO: check strlen(channel_desc) < rig->caps->chan_desc_sz */
 		if (chan_caps[1].type == RIG_MTYPE_PRIO)
 			sprintf(membuf, "MNA %sI-%01d,%s",mr_extra,channel_num,channel_desc);
 		else
 			sprintf(membuf, "MNA %s%03d,%s",mr_extra,channel_num,channel_desc);
 
-		retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+		retval = kenwood_transaction(rig, membuf, NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 	}
diff --git a/kenwood/thg71.c b/kenwood/thg71.c
index 177844f13..999f7f49e 100644
--- a/kenwood/thg71.c
+++ b/kenwood/thg71.c
@@ -194,10 +194,9 @@ int thg71_decode_event (RIG *rig)
 {
     char asyncbuf[ACKBUF_LEN];
     int retval;
-    size_t asyncbuf_len = ACKBUF_LEN;
     rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
-    retval = kenwood_transaction(rig, NULL, asyncbuf, &asyncbuf_len);
+    retval = kenwood_transaction(rig, NULL, asyncbuf, sizeof (asyncbuf));
     if (retval != RIG_OK)
         return retval;
 
@@ -302,7 +301,6 @@ int thg71_get_mode (RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
 {
     char ackbuf[ACKBUF_LEN];
     int retval;
-    size_t ack_len=ACKBUF_LEN;
     int step;
     freq_t freq;
 
@@ -317,7 +315,7 @@ int thg71_get_mode (RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
 	}
 
 	/* try to guess from frequency */
-    retval = kenwood_transaction(rig, "FQ", ackbuf, &ack_len);
+  retval = kenwood_transaction(rig, "FQ", ackbuf, sizeof (ackbuf));
         if (retval != RIG_OK)
         return retval;
 
@@ -337,9 +335,8 @@ int thg71_get_mode (RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
 /* --------------------------------------------------------------------- */
 int thg71_set_vfo (RIG *rig, vfo_t vfo)
 {
-    char vfobuf[16], ackbuf[ACKBUF_LEN];
+    char vfobuf[16];
     int retval;
-    size_t ack_len;
 
     rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
@@ -356,8 +353,7 @@ int thg71_set_vfo (RIG *rig, vfo_t vfo)
             return -RIG_EVFO;
         }
 
-    ack_len = 0;
-    retval = kenwood_transaction(rig, vfobuf, ackbuf, &ack_len);
+        retval = kenwood_transaction(rig, vfobuf, NULL, 0);
         if (retval != RIG_OK)
         return retval;
 
@@ -369,10 +365,9 @@ int thg71_get_vfo (RIG *rig, vfo_t *vfo)
 {
     char ackbuf[ACKBUF_LEN];
     int retval;
-    size_t ack_len=ACKBUF_LEN;
     int vch;
 
-    retval = kenwood_transaction(rig, "VMC 0" , ackbuf, &ack_len);
+    retval = kenwood_transaction(rig, "VMC 0" , ackbuf, sizeof (ackbuf));
         if (retval != RIG_OK)
         return retval;
 
@@ -395,16 +390,13 @@ int thg71_get_vfo (RIG *rig, vfo_t *vfo)
 /* --------------------------------------------------------------------- */
 int thg71_set_func(RIG *rig, vfo_t vfo, setting_t func, int status)
 {
-    char ackbuf[ACKBUF_LEN];
     int retval;
-    size_t ack_len;
 
      if(func != RIG_FUNC_TBURST)
 		return -RIG_EINVAL;
 
-    ack_len = 0;
     if(status==1) {
-    retval = kenwood_transaction(rig, "TT", ackbuf, &ack_len);
+      retval = kenwood_transaction(rig, "TT", NULL, 0);
         if (retval != RIG_OK)
         	return retval;
 
@@ -421,7 +413,6 @@ int thg71_open(RIG *rig)
 {
     char ackbuf[ACKBUF_LEN],*strl,*stru;
     int retval,i;
-    size_t ack_len=ACKBUF_LEN;
     const freq_range_t frend=RIG_FRNG_END;
 
     /* this will check the model id */
@@ -430,8 +421,7 @@ int thg71_open(RIG *rig)
         return retval;
 
 	/* fill state.rx/tx range_list */
-    ack_len=ACKBUF_LEN;
-    retval = kenwood_transaction(rig, "FL", ackbuf, &ack_len);
+    retval = kenwood_transaction(rig, "FL", ackbuf, sizeof (ackbuf));
         if (retval != RIG_OK)
         	return retval;
 
diff --git a/kenwood/tmd710.c b/kenwood/tmd710.c
index 86a05eb4f..e6d1cde6e 100644
--- a/kenwood/tmd710.c
+++ b/kenwood/tmd710.c
@@ -812,17 +812,17 @@ int
 tmd710_get_vfo_char(RIG *rig, vfo_t *vfo, char *vfoch)
 {
 	char cmdbuf[10], buf[10], vfoc;
-	size_t buf_size=10;
 	int retval;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
 	/* Get VFO band */
 	
-	retval = kenwood_transaction(rig, "BC", buf, &buf_size);
+	retval = kenwood_transaction(rig, "BC", buf, sizeof (buf));
 	if (retval != RIG_OK)
 		return retval;
-	switch (buf_size) {
+  size_t length = strlen (buf);
+	switch (length) {
 	case 6: /*intended for D700 BC 0,0*/
 	  if ((buf[0]=='B') &&(buf[1]=='C') && (buf[2]==' ') && (buf[4]=',')){
 	    vfoc = buf[3];
@@ -832,7 +832,7 @@ tmd710_get_vfo_char(RIG *rig, vfo_t *vfo, char *vfoch)
 	  }
 	  break;
 	default:
-	  rig_debug(RIG_DEBUG_ERR, "%s: Unexpected answer length '%c'\n", __func__, buf_size);
+	  rig_debug(RIG_DEBUG_ERR, "%s: Unexpected answer length '%c'\n", __func__, length);
 	  return -RIG_EPROTO;
 	  break;
 	}
@@ -907,8 +907,6 @@ int tmd710_set_vfo (RIG *rig, vfo_t vfo)
     char vfobuf[16], ackbuf[16];
     int vfonum, txvfonum, vfomode=0;
     int retval;
-    size_t ack_len;
-
 
     rig_debug(RIG_DEBUG_TRACE, "%s: called %s\n", __func__, rig_strvfo(vfo));
 
@@ -928,9 +926,8 @@ int tmd710_set_vfo (RIG *rig, vfo_t vfo)
             break;
         case RIG_VFO_MEM:
             /* get current band */
-	  snprintf(vfobuf, 10, "BC");
-            ack_len=16;
-            retval = kenwood_transaction(rig, vfobuf, ackbuf, &ack_len);
+          snprintf(vfobuf, 10, "BC");
+          retval = kenwood_transaction(rig, vfobuf, ackbuf, sizeof (ackbuf));
             if (retval != RIG_OK)
                 return retval;
             txvfonum = vfonum = ackbuf[3]-'0';
diff --git a/kenwood/tmv7.c b/kenwood/tmv7.c
index 10353fc24..690d6e3ea 100644
--- a/kenwood/tmv7.c
+++ b/kenwood/tmv7.c
@@ -223,10 +223,9 @@ int tmv7_decode_event (RIG *rig)
 {
     char asyncbuf[ACKBUF_LEN];
     int retval;
-    size_t asyncbuf_len = ACKBUF_LEN;
     rig_debug(RIG_DEBUG_TRACE, "%s: called\n", __func__);
 
-    retval = kenwood_transaction(rig, NULL, asyncbuf, &asyncbuf_len);
+    retval = kenwood_transaction(rig, NULL, asyncbuf, sizeof (asyncbuf));
     if (retval != RIG_OK)
         return retval;
 
@@ -332,7 +331,6 @@ int tmv7_set_vfo (RIG *rig, vfo_t vfo)
 {
     char vfobuf[16], ackbuf[ACKBUF_LEN];
     int retval;
-    size_t ack_len;
 
     rig_debug(RIG_DEBUG_TRACE, "%s: called %d\n", __func__,vfo);
 
@@ -346,8 +344,7 @@ int tmv7_set_vfo (RIG *rig, vfo_t vfo)
             break;
         case RIG_VFO_MEM:
             sprintf(vfobuf, "BC");
-    	    ack_len=ACKBUF_LEN;
-	    retval = kenwood_transaction(rig, vfobuf, ackbuf, &ack_len);
+            retval = kenwood_transaction(rig, vfobuf, ackbuf, sizeof (ackbuf));
 	    if (retval != RIG_OK) return retval;
             sprintf(vfobuf, "VMC %c,2",ackbuf[3]);
             break;
@@ -356,8 +353,7 @@ int tmv7_set_vfo (RIG *rig, vfo_t vfo)
             return -RIG_EVFO;
 	}
 
-    ack_len=0;
-    retval = kenwood_transaction(rig, vfobuf, ackbuf, &ack_len);
+    retval = kenwood_transaction(rig, vfobuf, NULL, 0);
 	if (retval != RIG_OK) {
             rig_debug(RIG_DEBUG_ERR, "%s: bad return \n", __func__);
         return retval;
@@ -379,8 +375,7 @@ int tmv7_set_vfo (RIG *rig, vfo_t vfo)
 	}
 
     rig_debug(RIG_DEBUG_TRACE, "%s: next2\n", __func__);
-    ack_len=0;
-    retval = kenwood_transaction(rig, vfobuf, ackbuf, &ack_len);
+    retval = kenwood_transaction(rig, vfobuf, NULL, 0);
 	if (retval != RIG_OK)
         return retval;
 
@@ -392,7 +387,6 @@ int tmv7_get_mode (RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
 {
     char ackbuf[ACKBUF_LEN];
     int retval;
-    size_t ack_len=ACKBUF_LEN;
     int step;
     freq_t freq;
 
@@ -407,7 +401,7 @@ int tmv7_get_mode (RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
 	}
 
 	/* try to guess from frequency */
-    retval = kenwood_transaction(rig, "FQ", ackbuf, &ack_len);
+  retval = kenwood_transaction(rig, "FQ", ackbuf, sizeof (ackbuf));
         if (retval != RIG_OK)
         return retval;
 
@@ -438,7 +432,6 @@ int tmv7_get_channel(RIG *rig, channel_t *chan)
 {
     char membuf[64],ackbuf[ACKBUF_LEN];
     int retval;
-    size_t ack_len;
     freq_t freq;
     char req[16],scf[128];
     int step, shift, rev, tone, ctcss, tonefq, ctcssfq;
@@ -478,8 +471,7 @@ int tmv7_get_channel(RIG *rig, channel_t *chan)
 	return -RIG_EINVAL;
 
     sprintf(membuf,"%s",req);
-    ack_len=ACKBUF_LEN;
-    retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+    retval = kenwood_transaction(rig, membuf, ackbuf, sizeof (ackbuf));
         if (retval != RIG_OK)
         	return retval;
 
@@ -522,8 +514,7 @@ int tmv7_get_channel(RIG *rig, channel_t *chan)
     if(chan->channel_num<223 && shift==0) {
 	req[5]='1';
         sprintf(membuf,"%s",req);
-        ack_len=ACKBUF_LEN;
-    	retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+        retval = kenwood_transaction(rig, membuf, ackbuf, sizeof (ackbuf));
         if (retval == RIG_OK) {
     		strcpy(scf,req);
     		strcat(scf,",%"SCNfreq",%d");
@@ -537,8 +528,7 @@ int tmv7_get_channel(RIG *rig, channel_t *chan)
 	    	sprintf(membuf,"MNA 0,%03d",chan->channel_num);
 	    else
 	    	sprintf(membuf,"MNA 1,%03d",chan->channel_num-100);
-        ack_len=ACKBUF_LEN;
-    	retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+      retval = kenwood_transaction(rig, membuf, ackbuf, sizeof (ackbuf));
         if (retval != RIG_OK)
         	return retval;
         memcpy(chan->channel_desc,&ackbuf[10],7);
@@ -549,9 +539,8 @@ int tmv7_get_channel(RIG *rig, channel_t *chan)
 /* --------------------------------------------------------------------- */
 int tmv7_set_channel(RIG *rig, const channel_t *chan)
 {
-    char membuf[ACKBUF_LEN],ackbuf[ACKBUF_LEN];
+    char membuf[ACKBUF_LEN];
     int retval;
-    size_t ack_len;
     char req[64];
     long freq;
     int step, shift, tone, ctcss, tonefq, ctcssfq;
@@ -634,16 +623,14 @@ int tmv7_set_channel(RIG *rig, const channel_t *chan)
                     req, (long)freq, step, shift, tone,
                     ctcss, tonefq, ctcssfq);
 
-    ack_len=0;
-    retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+    retval = kenwood_transaction(rig, membuf, NULL, 0);
         if (retval != RIG_OK)
         	return retval;
 
     if(chan->tx_freq!=RIG_FREQ_NONE) {
     	req[5]='1';
     	sprintf(membuf, "%s,%011"PRIll",%01d", req, (int64_t)chan->tx_freq, step);
-        ack_len=0;
-    	retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+      retval = kenwood_transaction(rig, membuf, NULL, 0);
         if (retval != RIG_OK)
         	return retval;
     }
@@ -653,8 +640,7 @@ int tmv7_set_channel(RIG *rig, const channel_t *chan)
 	    	sprintf(membuf,"MNA 0,%03d,%s",chan->channel_num,chan->channel_desc);
 	    else
 	    	sprintf(membuf,"MNA 1,%03d,%s",chan->channel_num-100,chan->channel_desc);
-    	ack_len=0;
-    	retval = kenwood_transaction(rig, membuf, ackbuf, &ack_len);
+      retval = kenwood_transaction(rig, membuf, NULL, 0);
         if (retval != RIG_OK)
         	return retval;
     }
diff --git a/kenwood/transfox.c b/kenwood/transfox.c
index 23247683a..79bd03454 100644
--- a/kenwood/transfox.c
+++ b/kenwood/transfox.c
@@ -196,14 +196,13 @@ int transfox_get_ptt(RIG *rig, vfo_t vfo, ptt_t *ptt)
 const char* transfox_get_info(RIG *rig)
 {
 	static char firmbuf[32];
-    size_t firmlen = sizeof firmbuf;
 	int retval;
 
 	rig_debug(RIG_DEBUG_TRACE, "%s called\n", __func__);
 
     firmbuf[0] = '\0';
 
-	retval = kenwood_transaction(rig, "CS", firmbuf, &firmlen);
+		retval = kenwood_transaction(rig, "CS", firmbuf, sizeof (firmbuf));
 	if (retval != RIG_OK)
 		return NULL;
 
diff --git a/kenwood/ts2000.c b/kenwood/ts2000.c
index b7e57d1ea..d0aa9a2e5 100644
--- a/kenwood/ts2000.c
+++ b/kenwood/ts2000.c
@@ -371,16 +371,16 @@ int ts2000_get_channel(RIG *rig, channel_t *chan)
 
 	int err;
 	char buf[52];
-	size_t buf_size = 52;
 	char cmd[8];
 	struct kenwood_priv_caps *caps = kenwood_caps(rig);
 
 	/* put channel num in the command string */
 	sprintf(cmd, "MR0%03d;", chan->channel_num);
 
-	err = kenwood_transaction(rig, cmd, buf, &buf_size );
+	err = kenwood_transaction(rig, cmd, buf, sizeof (buf));
 	if (err != RIG_OK)
 		return err;
+	size_t length = strlen (buf);
 	memset(chan, 0x00, sizeof(channel_t));
 
 	chan->vfo = RIG_VFO_MEM;
@@ -393,7 +393,7 @@ int ts2000_get_channel(RIG *rig, channel_t *chan)
 	 */
 	/* First check if a name is assigned.
 	   Name is returned at positions 41-48 (counting from 0) */
-	if( buf_size > 41 ){
+	if( length > 41 ){
 // 	  rig_debug(RIG_DEBUG_VERBOSE, "Copying channel description: %s\n", &buf[ 41 ] );
 	  strcpy( chan->channel_desc, &buf[ 41 ] );
 	}
@@ -505,8 +505,7 @@ int ts2000_get_channel(RIG *rig, channel_t *chan)
 
 	/* Check split freq */
 	cmd[2] = '1';
-	buf_size = 52;
-	err = kenwood_transaction(rig, cmd, buf, &buf_size );
+	err = kenwood_transaction(rig, cmd, buf, sizeof (buf));
 	if (err != RIG_OK)
 		return err;
 
@@ -642,8 +641,7 @@ int ts2000_set_channel(RIG *rig, const channel_t *chan)
 		);
 	rig_debug( RIG_DEBUG_VERBOSE, "The command will be: %s\n", buf );
 
-    size_t tmp=0;
-	err = kenwood_transaction(rig, buf, NULL, &tmp );
+	err = kenwood_transaction(rig, buf, NULL, 0);
 	if (err != RIG_OK)
 		return err;
 	
@@ -666,8 +664,7 @@ int ts2000_set_channel(RIG *rig, const channel_t *chan)
 		);
 	  rig_debug( RIG_DEBUG_VERBOSE, "Split, the command will be: %s\n", buf );
 	
-      tmp = 0;
-	  err = kenwood_transaction(rig, buf, NULL, &tmp );
+	  err = kenwood_transaction(rig, buf, NULL, 0);
 	}
 	return err;
 }
@@ -687,9 +684,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 		switch (level) {
 
 		case RIG_LEVEL_PREAMP:
-			retval = kenwood_transaction (rig, "PA", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "PA", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if ((lvl_len != 4)){ /*TS-2000 returns 4 chars for PA; */
 				rig_debug(RIG_DEBUG_ERR,"%s: unexpected answer len=%d\n",
 					       __func__, lvl_len);
@@ -704,10 +702,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_ATT:
-			retval = kenwood_transaction (rig, "RA", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "RA", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
-
+			lvl_len = strlen (lvlbuf);
 			if ((lvl_len != 6)){ /* TS-2000 returns 6 chars for RA; */
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 								"unexpected answer len=%d\n", lvl_len);
@@ -723,9 +721,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_VOX:
-			retval = kenwood_transaction (rig, "VD", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "VD", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 6) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -736,9 +735,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 	        case RIG_LEVEL_AF:
-			retval = kenwood_transaction (rig, "AG0", lvlbuf, &lvl_len);
+						retval = kenwood_transaction (rig, "AG0", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 6) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -749,9 +749,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_RF:
-			retval = kenwood_transaction (rig, "RG", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "RG", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 5) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -762,9 +763,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_SQL:
-			retval = kenwood_transaction (rig, "SQ0", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "SQ0", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 6) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -775,9 +777,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_CWPITCH:
-			retval = kenwood_transaction (rig, "EX0310000", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "EX0310000", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 15) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d answer=%s\n", lvl_len, lvlbuf);
@@ -788,9 +791,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_RFPOWER:
-			retval = kenwood_transaction (rig, "PC", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "PC", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 5) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -801,9 +805,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
         	  	break;
 
 		case RIG_LEVEL_MICGAIN:
-			retval = kenwood_transaction (rig, "MG", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "MG", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 5) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -814,9 +819,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_KEYSPD:
-			retval = kenwood_transaction (rig, "KS", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "KS", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 5) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -831,9 +837,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_COMP:
-			retval = kenwood_transaction (rig, "PL", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "PL", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 8) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -856,9 +863,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_BKINDL:
-			retval = kenwood_transaction (rig, "SD", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "SD", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 6) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -873,9 +881,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 		    break;
 
 		case RIG_LEVEL_METER:
-			retval = kenwood_transaction (rig, "RM", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "RM", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 7) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -886,9 +895,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_VOXGAIN:
-			retval = kenwood_transaction (rig, "VG", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "VG", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 5) {
 				rig_debug(RIG_DEBUG_ERR,"ts2000_get_level: "
 					"unexpected answer len=%d\n", lvl_len);
@@ -904,10 +914,10 @@ int ts2000_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 
 		case RIG_LEVEL_RAWSTR:
 		case RIG_LEVEL_STRENGTH:
-			retval = kenwood_transaction (rig, "SM0", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "SM0", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
-
+			lvl_len = strlen (lvlbuf);
 			if (( (lvl_len !=7)) || lvlbuf[1] != 'M') {
 				/* TS-2000 returns 8 bytes for S meter level */
 				rig_debug(RIG_DEBUG_ERR,"%s: wrong answer len=%d\n",
diff --git a/kenwood/ts480.c b/kenwood/ts480.c
index dd31e9956..0f499bf09 100644
--- a/kenwood/ts480.c
+++ b/kenwood/ts480.c
@@ -47,13 +47,12 @@ static const char *
 kenwood_ts480_get_info (RIG * rig)
 {
   char firmbuf[50];
-  size_t firm_len;
   int retval;
 
-  firm_len = 50;
-  retval = kenwood_transaction (rig, "TY", firmbuf, &firm_len);
+  retval = kenwood_transaction (rig, "TY", firmbuf, sizeof (firmbuf));
   if (retval != RIG_OK)
     return NULL;
+  size_t firm_len = strlen (firmbuf);
   if (firm_len != 5)
     {
       rig_debug (RIG_DEBUG_ERR, "kenwood_get_info: wrong answer len=%d\n", firm_len);
@@ -149,16 +148,17 @@ int
 kenwood_ts480_get_level (RIG * rig, vfo_t vfo, setting_t level, value_t * val)
 {
   char ackbuf[50];
-  size_t ack_len = 50;
+  size_t ack_len;
   int levelint;
   int retval;
 
   switch (level)
     {
     case RIG_LEVEL_RFPOWER:
-      retval = kenwood_transaction (rig, "PC", ackbuf, &ack_len);
+      retval = kenwood_transaction (rig, "PC", ackbuf, sizeof (ackbuf));
       if (RIG_OK != retval)
 	return retval;
+      ack_len = strlen (ackbuf);
       if (5 != ack_len)
 	return -RIG_EPROTO;
       if (1 != sscanf (&ackbuf[2], "%d", &levelint))
@@ -167,9 +167,10 @@ kenwood_ts480_get_level (RIG * rig, vfo_t vfo, setting_t level, value_t * val)
       return RIG_OK;
 
     case RIG_LEVEL_AF:
-      retval = kenwood_transaction (rig, "AG0", ackbuf, &ack_len);
+      retval = kenwood_transaction (rig, "AG0", ackbuf, sizeof (ackbuf));
       if (RIG_OK != retval)
 	return retval;
+      ack_len = strlen (ackbuf);
       if (6 != ack_len)
 	return -RIG_EPROTO;
       if (1 != sscanf (&ackbuf[3], "%d", &levelint))
@@ -178,9 +179,10 @@ kenwood_ts480_get_level (RIG * rig, vfo_t vfo, setting_t level, value_t * val)
       return RIG_OK;
 
     case RIG_LEVEL_RF:
-      retval = kenwood_transaction (rig, "RG", ackbuf, &ack_len);
+      retval = kenwood_transaction (rig, "RG", ackbuf, sizeof (ackbuf));
       if (RIG_OK != retval)
 	return retval;
+      ack_len = strlen (ackbuf);
       if (5 != ack_len)
 	return -RIG_EPROTO;
       if (1 != sscanf (&ackbuf[2], "%d", &levelint))
@@ -189,9 +191,10 @@ kenwood_ts480_get_level (RIG * rig, vfo_t vfo, setting_t level, value_t * val)
       return RIG_OK;
 
     case RIG_LEVEL_SQL:
-      retval = kenwood_transaction (rig, "SQ0", ackbuf, &ack_len);
+      retval = kenwood_transaction (rig, "SQ0", ackbuf, sizeof (ackbuf));
       if (RIG_OK != retval)
 	return retval;
+      ack_len = strlen (ackbuf);
       if (6 != ack_len)
 	return -RIG_EPROTO;
       if (1 != sscanf (&ackbuf[3], "%d", &levelint))
@@ -200,9 +203,10 @@ kenwood_ts480_get_level (RIG * rig, vfo_t vfo, setting_t level, value_t * val)
       return RIG_OK;
 
     case RIG_LEVEL_AGC:
-      retval = kenwood_transaction (rig, "GT", ackbuf, &ack_len);
+      retval = kenwood_transaction (rig, "GT", ackbuf, sizeof (ackbuf));
       if (RIG_OK != retval)
 	return retval;
+      ack_len = strlen (ackbuf);
       if (5 != ack_len)
 	return -RIG_EPROTO;
       switch (ackbuf[4])
diff --git a/kenwood/ts570.c b/kenwood/ts570.c
index 113607aef..2ef49e494 100644
--- a/kenwood/ts570.c
+++ b/kenwood/ts570.c
@@ -51,19 +51,17 @@ static struct kenwood_priv_caps ts570_priv_caps  = {
 static int ts570_get_mode(RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
 {
   char buf[50];
-  size_t buf_len;
+  size_t length;
   int retval;
 
-
-  buf_len = 50;
-  retval = kenwood_transaction (rig, "MD", buf, &buf_len);
+  retval = kenwood_transaction (rig, "MD", buf, sizeof (buf));
   if (retval != RIG_OK)
     return retval;
-
-  if (buf_len != 3 || buf[1] != 'D')
+	length = strlen (buf);
+  if (length != 3 || buf[1] != 'D')
   {
     rig_debug(RIG_DEBUG_ERR,"ts570_get_mode: unexpected MD answer, len=%d\n",
-      buf_len);
+      length);
     return -RIG_ERJCTED;
   }
 
@@ -96,13 +94,13 @@ static int ts570_get_mode(RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
     case RIG_MODE_CWR:
     case RIG_MODE_RTTY:
     case RIG_MODE_RTTYR:
-      buf_len = 50;
-      retval = kenwood_transaction (rig, "FW", buf, &buf_len);
+      retval = kenwood_transaction (rig, "FW", buf, sizeof (buf));
       if (retval != RIG_OK) return retval;
-      if (buf_len != 6 || buf[1] != 'W')
+			length = strlen (buf);
+      if (length != 6 || buf[1] != 'W')
       {
         rig_debug(RIG_DEBUG_ERR,
-          "ts570_get_mode: unexpected FW answer, len=%d\n", buf_len);
+          "ts570_get_mode: unexpected FW answer, len=%d\n", length);
         return -RIG_ERJCTED;
       }
       *width = atoi(&buf[2]);
@@ -111,13 +109,13 @@ static int ts570_get_mode(RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
     case RIG_MODE_LSB:
     case RIG_MODE_FM:
     case RIG_MODE_AM:
-      buf_len = 50;
-      retval = kenwood_transaction (rig, "SL", buf, &buf_len);
+      retval = kenwood_transaction (rig, "SL", buf, sizeof (buf));
       if (retval != RIG_OK) return retval;
-      if (buf_len != 4 || buf[1] != 'L')
+			length = strlen (buf);
+      if (length != 4 || buf[1] != 'L')
       {
         rig_debug(RIG_DEBUG_ERR,
-          "ts570_get_mode: unexpected SL answer, len=%d\n", buf_len);
+          "ts570_get_mode: unexpected SL answer, len=%d\n", length);
         return -RIG_ERJCTED;
       }
       *width = 50 * atoi(&buf[2]);
@@ -230,10 +228,10 @@ int ts570_get_func(RIG *rig, vfo_t vfo, setting_t func, int *status)
 		 */
 		switch (func) {
 		case RIG_FUNC_NR:
-			retval = kenwood_transaction (rig, "NR", fctbuf, &fct_len);
+			retval = kenwood_transaction (rig, "NR", fctbuf, sizeof (fctbuf));
 			if (retval != RIG_OK)
 				return retval;
-
+			fct_len = strlen (fctbuf);
 			if (fct_len != 3) {
 				rig_debug(RIG_DEBUG_ERR,"kenwood_get_func: "
 					"wrong answer len=%d\n", fct_len);
@@ -244,10 +242,10 @@ int ts570_get_func(RIG *rig, vfo_t vfo, setting_t func, int *status)
 			break;
 
 		case RIG_FUNC_TUNER:
-			retval = kenwood_transaction (rig, "AC", fctbuf, &fct_len);
+			retval = kenwood_transaction (rig, "AC", fctbuf, sizeof (fctbuf));
 			if (retval != RIG_OK)
 				return retval;
-
+			fct_len = strlen (fctbuf);
 			if (fct_len != 5) {
 				rig_debug(RIG_DEBUG_ERR,"kenwood_get_func: "
 					"wrong answer len=%d\n", fct_len);
@@ -323,7 +321,7 @@ int
 ts570_get_level (RIG * rig, vfo_t vfo, setting_t level, value_t * val)
 {
   char ackbuf[50];
-  size_t ack_len = 50;
+  size_t ack_len;
   int levelint;
   int retval;
   int i;
@@ -332,9 +330,10 @@ ts570_get_level (RIG * rig, vfo_t vfo, setting_t level, value_t * val)
     {
     case RIG_LEVEL_RFPOWER:
       /* ts570d returns 5..100 measured in watt */
-      retval = kenwood_transaction (rig, "PC", ackbuf, &ack_len);
+      retval = kenwood_transaction (rig, "PC", ackbuf, sizeof (ackbuf));
       if (RIG_OK != retval)
 	return retval;
+			ack_len = strlen (ackbuf);
       if (5 != ack_len)
 	return -RIG_EPROTO;
       if (1 != sscanf (&ackbuf[2], "%d", &levelint))
@@ -344,9 +343,10 @@ ts570_get_level (RIG * rig, vfo_t vfo, setting_t level, value_t * val)
 
     case RIG_LEVEL_MICGAIN:
       /* reads from 0..100 */
-      retval = kenwood_transaction (rig, "MG", ackbuf, &ack_len);
+      retval = kenwood_transaction (rig, "MG", ackbuf, sizeof (ackbuf));
       if (RIG_OK != retval)
         return retval;
+			ack_len = strlen (ackbuf);
       if (5 != ack_len)
         return -RIG_EPROTO;
       if (1 != sscanf (&ackbuf[2], "%d", &levelint))
@@ -355,10 +355,10 @@ ts570_get_level (RIG * rig, vfo_t vfo, setting_t level, value_t * val)
       return RIG_OK;
 
     case RIG_LEVEL_PREAMP:
-	retval = kenwood_transaction (rig, "PA", ackbuf, &ack_len);
+			retval = kenwood_transaction (rig, "PA", ackbuf, sizeof (ackbuf));
 	if (retval != RIG_OK)
 	    return retval;
-
+			ack_len = strlen (ackbuf);
 	if (3  != ack_len) {
 	    rig_debug(RIG_DEBUG_ERR,"%s: unexpected answer len=%d\n",
 			__func__, ack_len);
@@ -394,17 +394,15 @@ ts570_get_level (RIG * rig, vfo_t vfo, setting_t level, value_t * val)
 int ts570_get_split_vfo(RIG * rig, vfo_t vfo, split_t * split, vfo_t * tx_vfo)
 {
 	char ack[10];
-	size_t acklen = 10;
 	char ack2[10];
-	size_t ack2len = 10;
 	int retval;
 
-	retval = kenwood_transaction(rig, "FR", ack, &acklen);
+	retval = kenwood_transaction(rig, "FR", ack, sizeof (ack));
 	if (retval != RIG_OK)
 		return retval;
 
 
-	retval = kenwood_transaction(rig, "FT", ack2, &ack2len);
+	retval = kenwood_transaction(rig, "FT", ack2, sizeof (ack2));
 	if (retval != RIG_OK)
 		return retval;
 
@@ -435,7 +433,6 @@ int ts570_set_split_vfo(RIG *rig, vfo_t vfo, split_t split, vfo_t txvfo)
 {
 	char cmdbuf[16], ackbuf[20];
 	int cmd_len, retval;
-	size_t ack_len;
 	unsigned char vfo_function;
 
 	if(vfo !=RIG_VFO_CURR) {
@@ -482,8 +479,7 @@ int ts570_set_split_vfo(RIG *rig, vfo_t vfo, split_t split, vfo_t txvfo)
 		if(vfo==RIG_VFO_CURR) {
 	  		/* switch to current RX VFO */
 			/* first ask for it */
-			ack_len = 10;
-			retval = kenwood_transaction(rig, "FR", ackbuf, &ack_len);
+			retval = kenwood_transaction(rig, "FR", ackbuf, sizeof (ackbuf));
 			if (retval != RIG_OK)
 				return retval;
 			/* and then set it to both vfo's */
@@ -514,9 +510,8 @@ int ts570_set_split_vfo(RIG *rig, vfo_t vfo, split_t split, vfo_t txvfo)
 
 int ts570_set_channel (RIG * rig, const channel_t * chan)
 {
-                char cmdbuf[30], membuf[30];
+                char cmdbuf[30];
                 int retval, cmd_len;
-		size_t mem_len;
 		int num,freq,tx_freq,tone;
 		char mode,tx_mode,tones;
 
@@ -547,8 +542,7 @@ int ts570_set_channel (RIG * rig, const channel_t * chan)
 		if (cmd_len < 0)
 			return -RIG_ETRUNC;
 
-                mem_len = 0;
-                retval = kenwood_transaction (rig, cmdbuf, membuf, &mem_len);
+                retval = kenwood_transaction (rig, cmdbuf, NULL, 0);
                 if (retval != RIG_OK)
                                 return retval;
 
@@ -557,8 +551,7 @@ int ts570_set_channel (RIG * rig, const channel_t * chan)
 		if (cmd_len < 0)
 			return -RIG_ETRUNC;
 
-                mem_len = 0;
-                retval = kenwood_transaction (rig, cmdbuf, membuf, &mem_len);
+                retval = kenwood_transaction (rig, cmdbuf, NULL, 0);
                 if (retval != RIG_OK)
                                 return retval;
 
@@ -569,13 +562,11 @@ int ts570_get_xit(RIG *rig, vfo_t vfo, shortfreq_t * rit)
 {
 	char infobuf[50];
 	int retval;
-	size_t info_len;
 
-	info_len = 50;
-	retval = kenwood_transaction (rig, "IF", infobuf, &info_len);
+	retval = kenwood_transaction (rig, "IF", infobuf, sizeof (infobuf));
 	if (retval != RIG_OK)
 		return retval;
-
+	size_t info_len = strlen (infobuf);
 	if (info_len != 37 || infobuf[1] != 'F') {
 	rig_debug(RIG_DEBUG_ERR,"kenwood_get_rit: wrong answer len=%d\n",
 					info_len);
@@ -593,20 +584,18 @@ int ts570_get_xit(RIG *rig, vfo_t vfo, shortfreq_t * rit)
 
 int ts570_set_rit(RIG * rig, vfo_t vfo, shortfreq_t rit)
 {
-        char buf[50], infobuf[50];
+        char buf[50];
 	unsigned char c;
         int retval, len, i;
-	size_t info_len;
 
-        info_len = 0;
         if (rit == 0) {
-		retval = kenwood_transaction(rig, "RT0", infobuf, &info_len);
+		retval = kenwood_transaction(rig, "RT0", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 		else
 			return RIG_OK;
 	} else {
-		retval = kenwood_transaction(rig, "RT1", infobuf, &info_len);
+		retval = kenwood_transaction(rig, "RT1", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 	}
@@ -619,15 +608,13 @@ int ts570_set_rit(RIG * rig, vfo_t vfo, shortfreq_t rit)
 	if (len < 0)
 		return -RIG_ETRUNC;
 
-        info_len = 0;
-        retval = kenwood_transaction(rig, "RC", infobuf, &info_len);
+        retval = kenwood_transaction(rig, "RC", NULL, 0);
 	if (retval != RIG_OK)
 		return retval;
 
         for (i = 0; i < abs(rint(rit/10)); i++)
         {
-                info_len = 0;
-                retval = kenwood_transaction(rig, buf, infobuf, &info_len);
+                retval = kenwood_transaction(rig, buf, NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
         }
@@ -637,20 +624,18 @@ int ts570_set_rit(RIG * rig, vfo_t vfo, shortfreq_t rit)
 
 int ts570_set_xit(RIG * rig, vfo_t vfo, shortfreq_t rit)
 {
-        char buf[50], infobuf[50];
+        char buf[50];
 	unsigned char c;
         int retval, len, i;
-	size_t info_len;
 
-        info_len = 0;
         if (rit == 0) {
-		retval = kenwood_transaction(rig, "XT0", infobuf, &info_len);
+		retval = kenwood_transaction(rig, "XT0", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 		else
 			return RIG_OK;
 	} else {
-		retval = kenwood_transaction(rig, "XT1", infobuf, &info_len);
+		retval = kenwood_transaction(rig, "XT1", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 	}
@@ -663,15 +648,13 @@ int ts570_set_xit(RIG * rig, vfo_t vfo, shortfreq_t rit)
 	if (len < 0)
 		return -RIG_ETRUNC;
 
-        info_len = 0;
-        retval = kenwood_transaction(rig, "RC", infobuf, &info_len);
+        retval = kenwood_transaction(rig, "RC", NULL, 0);
 	if (retval != RIG_OK)
 		return retval;
 
         for (i = 0; i < abs(rint(rit/10)); i++)
         {
-                info_len = 0;
-                retval = kenwood_transaction(rig, buf, infobuf, &info_len);
+                retval = kenwood_transaction(rig, buf, NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
         }
diff --git a/kenwood/ts850.c b/kenwood/ts850.c
index 8609410c1..73b874226 100644
--- a/kenwood/ts850.c
+++ b/kenwood/ts850.c
@@ -242,18 +242,16 @@ const struct rig_caps ts850_caps = {
 
 int ts850_set_rit(RIG * rig, vfo_t vfo, shortfreq_t rit)
 {
-	char buf[50], infobuf[50];
+	char buf[50];
 	unsigned char c;
 	int retval, i;
-	size_t info_len;
 
-	info_len = 0;
 	if (rit == 0) {
-		retval = kenwood_transaction(rig, "RT0", infobuf, &info_len);
+		retval = kenwood_transaction(rig, "RT0", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 	} else {
-		retval = kenwood_transaction(rig, "RT1", infobuf, &info_len);
+		retval = kenwood_transaction(rig, "RT1", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 	}
@@ -264,15 +262,13 @@ int ts850_set_rit(RIG * rig, vfo_t vfo, shortfreq_t rit)
 		c = 'D';
 	sprintf(buf, "R%c", c);
 
-	info_len = 0;
-	retval = kenwood_transaction(rig, "RC", infobuf, &info_len);
+	retval = kenwood_transaction(rig, "RC", NULL, 0);
 	if (retval != RIG_OK)
 		return retval;
 
 	for (i = 0; i < abs(rint(rit/20)); i++)
 	{
-		info_len = 0;
-		retval = kenwood_transaction(rig, buf, infobuf, &info_len);
+		retval = kenwood_transaction(rig, buf, NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 	}
@@ -282,24 +278,21 @@ int ts850_set_rit(RIG * rig, vfo_t vfo, shortfreq_t rit)
 
 int ts850_set_xit(RIG * rig, vfo_t vfo, shortfreq_t xit)
 {
-	char buf[50], infobuf[50];
+	char buf[50];
 	unsigned char c;
 	int retval, i;
-	size_t info_len;
 
-	info_len = 0;
 	if (xit == 0) {
-		retval = kenwood_transaction(rig, "XT0", infobuf, &info_len);
+		retval = kenwood_transaction(rig, "XT0", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 	} else {
-		retval = kenwood_transaction(rig, "XT1", infobuf, &info_len);
+		retval = kenwood_transaction(rig, "XT1", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 	}
 
-	info_len = 0;
-	retval = kenwood_transaction(rig, "RC", infobuf, &info_len);
+	retval = kenwood_transaction(rig, "RC", NULL, 0);
 	if (retval != RIG_OK)
 		return retval;
 
@@ -311,8 +304,7 @@ int ts850_set_xit(RIG * rig, vfo_t vfo, shortfreq_t xit)
 
 	for (i = 0; i < abs(rint(xit/20)); i++)
 	{
-		info_len = 0;
-		retval = kenwood_transaction(rig, buf, infobuf, &info_len);
+		retval = kenwood_transaction(rig, buf, NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
 	}
@@ -341,23 +333,20 @@ int ts850_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 {
 	char lvlbuf[50];
 	int i, retval;
-	size_t lvl_len;
 
 	if(vfo!=RIG_VFO_CURR)
 		return -RIG_EINVAL;
 
 	switch (level) {
 		case RIG_LEVEL_RAWSTR:
-		lvl_len = 50;
-		retval = kenwood_transaction (rig, "SM", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "SM", lvlbuf, sizeof (lvlbuf));
 		if (retval != RIG_OK)
 			return retval;
 		val->i=atoi(&lvlbuf[2]);
 		break;
 
 		case RIG_LEVEL_STRENGTH:
-		lvl_len = 50;
-		retval = kenwood_transaction (rig, "SM", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "SM", lvlbuf, sizeof (lvlbuf));
 		if (retval != RIG_OK)
 			return retval;
 		val->i=atoi(&lvlbuf[2]);
@@ -366,12 +355,10 @@ int ts850_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 		break;
 
 		case RIG_LEVEL_SWR:
-			lvl_len = 0;
-		retval = kenwood_transaction (rig, "RM1", lvlbuf, &lvl_len);
+		retval = kenwood_transaction (rig, "RM1", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
-		lvl_len = 50;
-		retval = kenwood_transaction (rig, "RM", lvlbuf, &lvl_len);
+		retval = kenwood_transaction (rig, "RM", lvlbuf, sizeof (lvlbuf));
 		if (retval != RIG_OK)
 			return retval;
 		i=atoi(&lvlbuf[3]);
@@ -382,32 +369,27 @@ int ts850_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 		break;
 
 		case RIG_LEVEL_COMP:
-			lvl_len = 0;
-		retval = kenwood_transaction (rig, "RM2", lvlbuf, &lvl_len);
+		retval = kenwood_transaction (rig, "RM2", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
-		lvl_len = 50;
-		retval = kenwood_transaction (rig, "RM", lvlbuf, &lvl_len);
+		retval = kenwood_transaction (rig, "RM", lvlbuf, sizeof (lvlbuf));
 		if (retval != RIG_OK)
 			return retval;
 		val->f=(float)atoi(&lvlbuf[3])/30.0;
 		break;
 
 		case RIG_LEVEL_ALC:
-			lvl_len = 0;
-		retval = kenwood_transaction (rig, "RM3", lvlbuf, &lvl_len);
+		retval = kenwood_transaction (rig, "RM3", NULL, 0);
 		if (retval != RIG_OK)
 			return retval;
-		lvl_len = 50;
-		retval = kenwood_transaction (rig, "RM", lvlbuf, &lvl_len);
+		retval = kenwood_transaction (rig, "RM", lvlbuf, sizeof (lvlbuf));
 		if (retval != RIG_OK)
 			return retval;
 		val->f=(float)atoi(&lvlbuf[3])/30.0;
 		break;
 
 		case RIG_LEVEL_CWPITCH:
-			lvl_len = 25;
-		retval = kenwood_transaction (rig, "PT", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "PT", lvlbuf, sizeof (lvlbuf));
 		if (retval != RIG_OK)
 			return retval;
 		val->i=atoi(&lvlbuf[2]);
@@ -423,9 +405,8 @@ int ts850_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 
 int ts850_set_channel (RIG * rig, const channel_t * chan)
 {
-	char cmdbuf[30], membuf[30];
+	char cmdbuf[30];
 	int retval;
-	size_t mem_len;
 	int num,freq,tx_freq,tone;
 	char mode,tx_mode,tones;
 
@@ -453,15 +434,13 @@ int ts850_set_channel (RIG * rig, const channel_t * chan)
 
 	sprintf(cmdbuf, "MW0 %02d%011d%c0%c%02d ",
 					num,freq,mode,tones,tone);
-	mem_len = 0;
-	retval = kenwood_transaction (rig, cmdbuf, membuf, &mem_len);
+	retval = kenwood_transaction (rig, cmdbuf, NULL, 0);
 	if (retval != RIG_OK)
 		return retval;
 
 	sprintf(cmdbuf, "MW1 %02d%011d%c0%c%02d ",
 					num,tx_freq,tx_mode,tones,tone);
-	mem_len = 0;
-	retval = kenwood_transaction (rig, cmdbuf, membuf, &mem_len);
+	retval = kenwood_transaction (rig, cmdbuf, NULL, 0);
 	if (retval != RIG_OK)
 		return retval;
 
diff --git a/kenwood/ts870s.c b/kenwood/ts870s.c
index b7645fac3..dd74583f6 100644
--- a/kenwood/ts870s.c
+++ b/kenwood/ts870s.c
@@ -67,11 +67,10 @@ static int ts870s_get_vfo(RIG *rig, vfo_t *vfo)
 
 
 		/* query RX VFO */
-		vfo_len = 50;
-		retval = kenwood_transaction (rig, "FR", vfobuf, &vfo_len);
+		retval = kenwood_transaction (rig, "FR", vfobuf, sizeof (vfobuf));
 		if (retval != RIG_OK)
 			return retval;
-
+		vfo_len = strlen (vfobuf);
 		if (vfo_len != 3 || vfobuf[1] != 'R') {
 			rig_debug(RIG_DEBUG_ERR,"%s: unexpected answer %s, "
 						"len=%d\n",__func__,vfobuf, vfo_len);
@@ -98,10 +97,10 @@ static int ts870s_get_mode(RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
   int retval;
 
   buf_len = 50;
-  retval = kenwood_transaction (rig, "MD", buf, &buf_len);
+  retval = kenwood_transaction (rig, "MD", buf, sizeof (buf));
   if (retval != RIG_OK)
     return retval;
-
+	buf_len = strlen (buf);
   if (buf_len != 3 || buf[1] != 'D')
   {
     rig_debug(RIG_DEBUG_ERR,"%s: unexpected MD answer, len=%d\n",
@@ -126,11 +125,10 @@ static int ts870s_get_mode(RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
       return -RIG_EINVAL;
   }
 
-  buf_len = 50;
-  retval = kenwood_transaction (rig, "FW", buf, &buf_len);
+  retval = kenwood_transaction (rig, "FW", buf, sizeof (buf));
   if (retval != RIG_OK)
     return retval;
-
+	buf_len = strlen (buf);
   if (buf_len != 6 || buf[1] != 'W')
   {
     rig_debug(RIG_DEBUG_ERR,"%s: unexpected FW answer, len=%d\n",
@@ -144,11 +142,10 @@ static int ts870s_get_mode(RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
     {
       /* we only have HPF value and need LPF as well to calculate bandwidth */
 
-      buf_len = 50;
-      retval = kenwood_transaction (rig, "IS", buf, &buf_len);
+      retval = kenwood_transaction (rig, "IS", buf, sizeof (buf));
       if (retval != RIG_OK)
 	return retval;
-
+	buf_len = strlen (buf);
       if (buf_len != 7 || buf[1] != 'S')
 	{
 	  rig_debug(RIG_DEBUG_ERR,"%s: unexpected IS answer, len=%d\n",
@@ -244,13 +241,12 @@ static int ts870s_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 		int lvl, retval;
 		int i, ret, agclevel;
 
-		lvl_len = 50;
 		switch (level) {
 		case RIG_LEVEL_STRENGTH:
-			retval = kenwood_transaction (rig, "SM", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "SM", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
-
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 6 || lvlbuf[1] != 'M') {
 				rig_debug(RIG_DEBUG_ERR,"ts870s_get_level: "
 								"wrong answer len=%d\n", lvl_len);
@@ -263,19 +259,16 @@ static int ts870s_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_SWR:
-			lvl_len = 50;
-			retval = kenwood_transaction (rig, "RM", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "RM", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
 			/* set meter to SWR if needed */
 			if (lvlbuf[2] != '1')
 			{
-				lvl_len = 0;
-				retval = kenwood_transaction (rig, "RM1", lvlbuf, &lvl_len);
+				retval = kenwood_transaction (rig, "RM1", NULL, 0);
 				if (retval != RIG_OK)
 					return retval;
-				lvl_len = 50;
-				retval = kenwood_transaction (rig, "RM", lvlbuf, &lvl_len);
+				retval = kenwood_transaction (rig, "RM", lvlbuf, sizeof (lvlbuf));
 				if (retval != RIG_OK)
 					return retval;
 			}
@@ -288,19 +281,16 @@ static int ts870s_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_COMP:
-			lvl_len = 50;
-			retval = kenwood_transaction (rig, "RM", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "RM", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
 			/* set meter to COMP if needed */
 			if (lvlbuf[2] != '2')
 			{
-				lvl_len = 0;
-				retval = kenwood_transaction (rig, "RM2", lvlbuf, &lvl_len);
+				retval = kenwood_transaction (rig, "RM2", NULL, 0);
 				if (retval != RIG_OK)
 					return retval;
-				lvl_len = 50;
-				retval = kenwood_transaction (rig, "RM", lvlbuf, &lvl_len);
+				retval = kenwood_transaction (rig, "RM", lvlbuf, sizeof (lvlbuf));
 				if (retval != RIG_OK)
 					return retval;
 			}
@@ -309,19 +299,16 @@ static int ts870s_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_ALC:
-			lvl_len = 50;
-			retval = kenwood_transaction (rig, "RM", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "RM", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
 			/* set meter to ALC if needed */
 			if (lvlbuf[2] != '3')
 			{
-				lvl_len = 0;
-				retval = kenwood_transaction (rig, "RM3", lvlbuf, &lvl_len);
+				retval = kenwood_transaction (rig, "RM3", NULL, 0);
 				if (retval != RIG_OK)
 					return retval;
-				lvl_len = 50;
-				retval = kenwood_transaction (rig, "RM", lvlbuf, &lvl_len);
+				retval = kenwood_transaction (rig, "RM", lvlbuf, sizeof (lvlbuf));
 				if (retval != RIG_OK)
 					return retval;
 			}
@@ -330,10 +317,10 @@ static int ts870s_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 
 		case RIG_LEVEL_ATT:
-			retval = kenwood_transaction (rig, "RA", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "RA", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
-
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 4) {
 				rig_debug(RIG_DEBUG_ERR,"ts870s_get_level: "
 								"unexpected answer len=%d\n", lvl_len);
@@ -357,9 +344,10 @@ static int ts870s_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 			break;
 		case RIG_LEVEL_RFPOWER:
 			/* RFPOWER is 0..100 and not 0..255 like all the other levels*/
-			retval = kenwood_transaction (rig, "PC", lvlbuf, &lvl_len);
+			retval = kenwood_transaction (rig, "PC", lvlbuf, sizeof (lvlbuf));
 			if (retval != RIG_OK)
 				return retval;
+			lvl_len = strlen (lvlbuf);
 			if (lvl_len != 5 || lvlbuf[1] != 'C')
 			{
 				rig_debug(RIG_DEBUG_ERR,"ts870s_get_level: "
diff --git a/src/iofunc.c b/src/iofunc.c
index 5494182f3..2396bf523 100644
--- a/src/iofunc.c
+++ b/src/iofunc.c
@@ -487,6 +487,9 @@ int HAMLIB_API read_string(hamlib_port_t *p, char *rxbuffer, size_t rxmax, const
   int rd_count, total_count = 0;
   int retval;
 
+	if (!p || !rxbuffer) return -RIG_EINVAL;
+	if (rxmax < 1) return 0;
+
   /*
    * Wait up to timeout ms.
    */