# Kenwood TM-D710E in packet mode: does not transmit

I own a Kenwood TM-D710E.

1. I connected it via the COM-connector on the panel to a Raspberry pi. On the panel I selected "packet12" (with the TNC button). After that, I can send TNC commands to the device using minicom.

2. Next step: I enter "KISS ON" and "RESTART" in minicom to activate KISS mode on the Kenwood.

3. After that I run /usr/sbin/kissattach -l /dev/ttyUSB1 ax0 on the Raspberry.

4. If I now enter axlisten -t -a and send packets using an other system (baofeng + tnc-pi), I can indeed see those packets via the Kenwood!

The problem now is sending. If I do:

beacon -s ax0 'this is a test - PD9FVH'


then the panel shows for a fraction of a second 'STA' but the Kenwood does not transmit anything - I verified this by listening on that frequency using the Baofeng.

Note that in "audio mode" everything works both ways. I can hear myself via the Baofeng and via the Kenwood.

The power supply can deliver 25A.

My question now is: Does anyone know why the Kenwood won't send?

• Hello Folkert, Thank you for a nice, detailed question! I took the liberty of adding some more relevant tags and making your question a little bit easier to read. The link is a Google search which includes links to the Kenwood TM-D710E manuals. Hope you don't mind. :-) – Mike Waters Sep 15 at 19:24

Found out what it is. Something really stupid.

Before I had a TNC-PI. That TNC-PI modem just starts sending as sook as it gets data. The Kenwood on the other hand checks for a signal on the waves. If any; no packet transmission. And apparently this controlled by the squelch. I had the squelch set to "always listen" but then the radio things there's a transmission...

@mike waters: I also had problems with RF in equipment, but that was not related to this problem. Replacing the powersupply of the RPI by something more sane and moving it away from the radio (it was lying on top of it) helped (the problem showed up by the serial-to-usb converter "falling from the USB bus").

• Very good! Please mark this as accepted, so that the system doesn't keep pushing this to the top. --Plus, you'll get a little points bonus.-- – Mike Waters Sep 16 at 13:31
• I don't believe one gets points for accepting one's own answer, but please do it anyway ;) – rclocher3 Sep 16 at 19:36
• @rclocher3 Ah, you're right! Thanks. ham.stackexchange.com/help/self-answer – Mike Waters Sep 16 at 20:18

This might be caused by RFI.

Perhaps RF might be getting into the other equipment —especially the Raspberry Pi— and causing this problem.

Does it help if you turn the Kenwood's power down to 5 watts, or better yet replacing the antenna with a dummy load?