MKM wrote :-
>We need new IF-DSP V/H/SHF radios with built in band scopes and
>modules up to 5GHZ.
and Ed wrote :-
>The solution is to use a SDR on the IF of your current radio. Then
>software can provide DSP, filtering, spectral and waterfall displays,
>I am testing the SDR-IQ using the 28-30 MHz output of the DEMI 144/28
>converter. 144-MHz is very commonly used IF for microwave converters.
A more modern approach would be to use an SDR at the RF frequency, with
direct conversion to baseband, thus eliminating the transverter
altogether. This is what the uWSDR (Microwave SDR) project is doing.
In a nutshell - using the latest components and modern circuit
topologies to realise a high-performance SDR operating at microwave
frequencies. The first products will be for the 2.3GHz (which includes
2.4GHz) band and a sister product for 144MHz. The software for the user
interface is new; the software for the low-level DSP is the same as used
on SDR-1000 and other SDRs.
More details can be found on the uWSDR website :-
and there is a Yahoo group for the developers and lurkers.
ON/G4KLX will give a remote presentation via the web at Dayton, and I
might be able to give a talk in person at Microwave Update.
There are umpteen possibilities for product options for satellite use,
such as a 2.4GHz only Rx, a crossband 1.3GHz Tx/2.4GHz Rx, etc. etc.
Development progress has been painfully slow; if anybody would like to
help with the design and development please contact one of the team.
for the uWSDR team
> One key
> component of failure analysis is the availability of data, especially
> My question is, can the satellite user community at large come up with a
> system that allows the routine capturing of satellite telemetry? Is
> there a role that AMSAT can play? What would it take?
> Thoughts are appreciated.
Here's my thoughts...
I would like to see a system put in place that is similar to
the one that was up and running while AO-40 was alive. That is,
multiple groundstations around the world could receive the
telemetry using whatever modem they used and forward that
telemetry over the Internet (in either realtime or via email)
to a central site which both archives and disseminates the
telemetry to other groundstations. The archives were
(and still are) publicly available on AMSAT web/ftp site at
I suppose if we asked the right people we could easily get
hard drive space on that server to start archiving telemetry
from other satellites.
A very nice side effect of the collection efforts was that you
could point your telemetry display program (which was not
necessarily the same as the program that collected the
telemetry and sent it to the server) at the telemetry server
and the server would send current live telemetry to you as
others sent their telemetry in to the server. In this way
you could watch ("Live!") the progress of the satellite even
when it was on the other side of the world and even if you
yourself lacked the radios and/or modems. This was a lot
By a curious coincidence, I have been working on a 9600 baud
soundcard demodulator for Echo along with a telemetry display
program and an Internet telemetry reflector.
Ok, who wants to help?