Digipeating via the ISS and NO-84 and with your TH-D72a

Recently I purchased a Kenwood TH-D72a to work the FM ham satellites, and because of its capacity to do APRS, I could digipeat my signal through the ISS.

I ran into a lot of frustration trying to find a decent tutorial how to setup the -72a for digipeating through the ISS, and what are the steps actually send an APRS message via the ISS.

So this is a quick and dirty tutorial. Too many steps and people get confused, like me….haha

Hopefully those who have a -72a are familiar with it, and can work through the menus without any problem. Here we go.

I highly recommend creating some pre-programmed messages using the MCP-4 software that can be download from kenwood

Set APRS path to “others” and use ARISS, this not only works for the ISS but for also PSAT (NO-84).

TNC settings should be at 1200bps, also select A-Band, as VFO A will be used.

Set radio for single VFO.  The operation frequency is 145.825.  This is the uplink and downlink frequency.

Set radio power setting to H (High)

Turn on the TNC, should see APRS12, if TNC button pressed twice, Packet will appear. Press TNC again, and start over. The letter “D” will also appear, which means the radio is in data mode.

Turn on GPS on the radio.

When ISS or NO-84 is AOS  or overhead with antenna pointed properly and GPS is flashing, press BCN. Depending on the angle of either vehicle, after beaconing, a response might come back, or other packet traffic can be heard on the radio. Squelch must be turned so it just quiets the noise. If not, no traffic will be sent.

If you hear another station and it shows up in the display, press List, MSG, select reply message and tap the Nav button twice.

If vehicle received packet, there will be an “ACK” reply in the display.

Other station should reply, if so repeat previous steps to end the QSO with final msg.


That’s about it, a quick and dirty tutorial. 

73,  Dave AC8YU