[amsat-bb] Expectations...

Clayton Coleman kayakfishtx at gmail.com
Fri Jan 2 06:10:56 UTC 2015

The #1 thing I've noticed is how much more important it is to tune for
Doppler shift than when the ISS was using the Kenwood radio.

I've done several tests decoding packets using my Kenwood TM-D700 which has
5 kHz tuning steps common on most 2m FM radios and then compared results to
my Yaesu FT-857D which has much finer incremental tuning.

In the past, I could decode most of a pass simply staying on 145.825 MHz.
Nowadays, I start decoding around 145.828 and usually by LOS I'm decoding
near 145.822.

With the smaller tuning steps of the FT-857D I am able to decode about 30%
more packets than my TM-D700.

Simply put, in the past a fixed station could stay on 145.825 MHz with
great results. Today, not so much.

On Jan 1, 2015 9:10 PM, "Kelley" <kshaddrick at jetup.net> wrote:

> I put up a new antenna for ISS work today. It's a home-built 2m turnstile
> with reflectors. Numbers wise (SWR, etc., as read on a MFJ analyzer) the
> antenna is working. I used the antenna a bit on APRS and was able to hear
> stations and be heard by stations.
> I listened to the ISS for 3 passes earlier today. On the first 2 passes I
> heard a number of stations, but was unable to digi via the ISS. On the
> third pass (about 40 degrees elevation at max and to the south), I was able
> to digi via the ISS (sorry if I have the terminology wrong here, I'm
> somewhat new at this).
> My question is, how often should I be able to digi via the ISS? Is it
> unusual to not be able to on a given pass (all 3 passes were higher
> elevation passes)? I know there are collisions and QRM involved and someone
> wins out. I don't have the best station (IC-706MKIIG and a turnstile
> antenna), I'm sure this plays a part.
> Curious what others have experienced.
> Thanks,
> --
> Kelley - WØRK
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