[amsat-bb] Re: TS2000 ~436.798 MHz Birdie Solution

Mike Miller mike.kc9doa at sbcglobal.net
Wed Nov 30 09:55:48 PST 2011

Hi John,

I had heard of the down converter solution before and purchased 
a used down converter. Unfortunately it seemed to pick up the TS-
2000 bird nearly as well as the TS-2000. I just lashed the setup 
together so maybe taking more care to isolate the converter from 
the TS-2000 might improve my results. I'll have to give it a try 

Mike kc9doa

On 30 Nov 2011 at 10:49, John Papay wrote:

> As many of you know, my satellite radio is a TS2000X.
> If you have visited my satellite webpage, you have seen
> many recordings of AO-27 and SO50 from AOS to LOS.  Most
> of these recordings were made when I was not sitting in
> front of the radio.
> At first I used a uhf mobile to hear AO-27 and SO-50.  The
> problem was that those radios were not computer controlled
> so you had to tune for the doppler.  That worked fine when
> I was in the shack, but it didn't work when I was away.  The
> obvious solution was another radio that didn't have the
> birdie
> problem, or a simple UHF to 10M downconverter which wouldn't
> have the birdie problem.  Back in the day, UHF and VHF down-
> converters were very popular because we didn't have a lot of
> DC to Light radios out there.  Now these converters are
> sitting
> in junk boxes and are long forgotten by their owners.
> One of the more popular manufacturers of these inexpensive
> downconverters was Hamtronics.  They made all kinds of stuff
> for repeaters etc.  At first their products were not that
> great,
> but they evolved into some better designs including their
> UHF to 10m downconverters.  Unfortunately most downconverter
> manufacturers stopped making them when the devices they were
> using
> became obsolete and unavailable.  The use of current
> production
> devices required a redesign of their PC boards and since the
> demand
> was no longer there, these products were abandoned.
> I was fortunate to find a Hamtronics converter on a qrz.com
> posting
> from several years back.  It never sold back then and the owner
> still
> had it.  I purchased it and ran some tests on it against the
> receiver
> in the TS2000.  It turned out that the downconverter had a
> slightly
> better sensitivity than the TS2000!
> The big concern when using a converter or preamp is the fear
> of
> transmitting into it and smoking the front end.  But the
> TS2000
> has an auxiliary antenna jack which is receive only and perfect
> for
> a downconverter output on HF.  As Drew mentioned, SatPC32 can
> compensate for a downconverter and tune the TS2000 for
> doppler
> in the 10m band.  This allowed me to track AO-27 AO-51 and
> SO-50
> unattended and make all those recordings without any human
> intervention.
> A coaxial transfer relay was inserted into the uhf antenna line
> so
> that when the converter was in use, the UHF antenna was
> switched
> to the downconverter input (which outputs to the aux antenna
> jack
> on the TS2000) and the UHF antenna jack on the TS2000 is
> switched
> to a dummy load.  So if you transmit on UHF, power goes into
> the
> dummy load and all equipment is safe.  When I want to transmit
> on
> UHF (VO-52 and AO-7 mode B), the coax relay switches the UHF
> antenna
> back to the UHF antenna port on the TS2000.  The downconverter
> is out
> of the antenna circuit at this point.  I did not use the
> downconverter
> when operating on FO-29 so the aux antenna jack had to be
> switched to
> normal in the tS2000, menu #18 (FO-29 is a linear bird that
> outputs on
> UHF, currently not working).
> Every owner of a TS2000 that operates satellites needs a UHF to
> 10M
> downconverter.  Hamtronics is making a VHF to 10M downconverter
> now.
> If everyone emailed them to encourage them to make a UHF model,
> they
> might just do it.  The only other solution is to make one
> yourself,
> or find a used downconverter or transverter that is gathering
> dust on
> someone's shelf.  I now have an IC910H and am doing comparisons
> against
> the TS2000.  My first impression it that I prefer the TS2000
> but that
> might be because I'm so familiar with it.  I use another TS2000
> in the
> mobile sat truck but don't have a downconverter for it.  I
> simply use
> a uhf mobile for receive on AO-27 and SO-50 since I'm in front
> of the
> radio and don't run it unattended.  I have a coax switch to
> switch
> the UHF antenna from the TS2000 to the UHF mobile.
> Now that AO-51 is silent, all of the FM operation is on SO-50
> and AO-27.
> If you have a TS2000, you'll want to investigate the use of a
> downconverter.
> 73,
> John K8YSE
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