Ham band digipeaters on the International Space Station

Paul Wilson KI4PW

There was so much good discussion and interesting topics raised at last night's meeting. I feel we could have gone on for hours.

Anyway, as a followup to the discussion about working the ISS digipeater:

There is a TNC (terminal node controller) available for less than $100 that will enable a smartphone to decode and encode APRS (AX.25) data via bluetooth. I have one. It works great with my FT60 with land-based APRS digipeaters, but I never thought about using it via the ISS. A smartphone app or tablet app would be ideal for most people, since I would think most operators are using portable antennas to track the ISS and can't be tethered to a desktop machine. I use an app called APRSDroid.

Here's the TNC I have:

Here are a few links on ISS digipeater operations, but note the latest information (the third link) that the UHF digipeater on the ISS is not in service. (NB: "current" info was posted 4/17/2017--nearly a year ago)

I'm not very experienced with satellite ops. I have listened to a few analog voice satellite passes, using my Arrow VHF/UHF antenna with the built-in duplexer. With CHIRP it's pretty easy to program my Yaesu FT60 or the Baofeng to operate on the uplink and downlink frequencies, and to program the five "pairs" to account for the Doppler shift during the pass.