[amsat-bb] Programming a Kenwood TH-D72A for ISS Digi Contacts

Patrick STODDARD (WD9EWK/VA7EWK) amsat-bb at wd9ewk.net
Wed Nov 9 01:35:58 UTC 2016


As AI6GS mentioned, you can program a group of 5 memory channels
that will compensate for Doppler on both the uplink and downlink
for the 437.550 MHz frequency now being used for the ISS packet
digipeater. That list is available at:


I also pinned my tweet from last week on my @WD9EWK Twitter
profile page with the same chart, which you can see at:


As for using your TH-D72A for making QSOs using the ISS packet
digipeater, you can use APRS messages to do that. You can define
some messages in advance, so you aren't having to enter those
messages on the HT's keypad, or you can do that. Typing on the
keypad is just like sending SMS messages on a flip-phone or other
"non-smart" mobile phone.

APRS messages are the way anyone working the digipeater can send
and receive text that shows up on the screens of any station.
The Kenwood APRS-ready radios will not display freeform text that
someone using a simple terminal program types. APRS messages
are sent in a format that contains the call signs of the two
stations, along with a line of text intended for the receiving

Using APRS messages, you are able to make the same types of
exchanges you would on any other satellite. Grid locators are the
most common item exchanged, but with the prepared messages you might
also send your name and/or location along with the grid locator.
You could skip sending your location in the APRS message, if you are
using the APRS functionality to beacon your location during the
ISS pass.

More stations are giving the ISS digipeater on 70cm a try, and many
are finding success using the 5-channel setup like I mentioned
on this list last week. If you are set up to work the ISS 70cm
digipeater by the end of the week, I will be on there from a hamfest
near Tucson this Saturday (12 November) morning.


Twitter: @WD9EWK

On Tue, Nov 8, 2016 at 10:03 PM, Les Rayburn <les at highnoonfilm.com> wrote:

> Just purchased a used Kenwood TH-D72A HT. Hoping to use it along with an
> Arrow antenna to make more satellite contacts while traveling. While I
> primarily expect to use it to make voice contacts on the FM birds, I’m also
> interested in making packet contacts through the International Space
> Station.
> Could someone point me towards a programming guide for this type of
> application? Any other pointers in using the radio to make packet QSOs
> through the ISS?
> Grateful for all suggestions.
> 73,
> Les Rayburn, N1LF

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