Hi Henk,

Thanks for sharing some of your experiences, very helpful. I'm not purposely doing APRS, just packet. Although it was a lot of fun to build, I think my turnstile antenna is not sufficient to allow the 3 or more digi's I would need to make an "official" contact. The bird is busier than I thought it was.

I decode about 5 or 6 stations per pass, I hear many many more that don't decode. Many of the signals seem strong enough, but no decode. I'm using a KPC-3+, perhaps the newer software/soundcard based systems are better at decoding.

Kelley - WØRK

On 1/3/2015 3:01 PM, PA3GUO wrote:

Hi Kelly,

Regarding APRS via the ISS;

A busy channel ... When I use 100W into my 2x6 elements antenna (with doppler correction) I can always get over the ISS APRS station. When lowering to 5W I get a problem, likely due to many many stations in Europe all transmitting at the same time. Note: I don't run often with 100W, in fact I rarely use APRS at all.

So, it's a busy channel, see also here: http://www.ariss.net/index2.cgi 00:00:57:07 : WB3FKP]CQ,RS0ISS*,qAR,KB3KBR-15::K8OE :35F here in Alden , PA - UR 599 today via ISS ! 00:00:57:10 : W3MAT]CQ,RS0ISS*,qAR,KB3KBR-15::WB3FKP :QSL Good Copy 00:00:57:12 : WB3FKP]CQ,RS0ISS*,qAR,KB3KBR-15::Heard :K0HCV-9,NX9G,WB8JAY,W3MAT,K8OE,KB1CHU That is 3 transmissions in 5 seconds (up and downlink means 6 transmissions in 5 seconds I believe). But it does show the satellite (ISS) hears MANY stations at the same time. Watch the footprint, pick your time, eg when it is over a more quiet area but still in range for you.

Antennas: The ISS turns and its construction sometimes blocks/shield the antenna's. You can see that during school contacts, when APRS and Voice run simultanious: https://www.youtube.com/watch?v=RfNM3bzRW_E Signal strengths varies independently on the 2 stations (watch the waterfall). In fact I believe that compared to ~8 years ago, the fading due to the ISS construction itself has increased enormous.

A lot of fun though! Even if nobody responds, if you hear your packet re-transmitted by ISS, you 'have been in space' already !!

Success & have fun! Henk, PA3GUO _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb