[amsat-bb] Re: TS2000 Birdie Follow-Up

Walter Holmes Walterh at k5wh.net
Wed Nov 30 13:18:57 PST 2011

I have used a HamTronics downconverter on my TS-2000x for many years, and it
works perfect.

But, to be clear, I am downconverting the UHF signal into the receive ONLY
jack of the radio, on 10 meters.

This virtually eliminates the birdie problem, and allows for full rig
control with SatPC32 just perfectly.

I have a coax switch on the UHF antenna, for when I need to work the UHF
birds that do not have an output on the birdie freq.

Sadly that it cost about $100.00 to resolve the issue, but that's a small
price to pay to still be able to use all the other features of the radio.


-----Original Message-----
From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
Behalf Of John Papay
Sent: Wednesday, November 30, 2011 1:13 PM
To: amsat-bb at amsat.org
Subject: [amsat-bb] TS2000 Birdie Follow-Up

KC9DOA mentions that he still had the birdie problem with a downconverter
and that is understandable.
The TS2000 radiates the birdie and if your downconverter is not shielded or
the UHF antenna is too close to the radio, you might still pick it up.
Simple experimentation will find the right combination to virtually
eliminate the birdie.  So try a UHF handi or mobile unit and see if it hears
the birdie on 436.798.  Then move things around to see if you can minimize
the effect.  I've been able to do that in the sat truck and don't have the
problem at the base station.  Try a dummy load on the UHF antenna jack on
TS2000 as well.  Use quality coax with good shielding.

Drew posted a link to High Sierra Microwave for a UHF down- converter that
is up-to-date in design and performance, all at a reasonable price.  The
specs call for a 5v supply but Bill N6GHZ advised that the converter will
operate fine up to 16vdc input.  No special supply required.  He also
mentioned that the converter will perform well from 432 to 438 MHz.  So this
is one possible source of a current production downconverter manufactured by
someone who knows satellites.  The output IF is lower but the TS2000
receiver is continuous so there should be no problem.  Instead of a 407MHz
offset, use 425MHz and the receiver shifts down to 10MHz for a 435MHz input:

doppler.sqf entry:

I've not seen a whole lot mentioned about the Funcube performance when
connected to a big antenna in a crowded RF environment.  I've had mine on
the KLM's and the performance is poor because of overload.  Cavity filters
work wonders but not everyone has them.
High Sierra also makes front end filters and filter/LNA combinations for the
Funcube as well as other products which make the Funcube more versatile.
It's worth checking out the webpage to see what is available.

John K8YSE  

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