[amsat-bb] LilacSat-2 FM Transponder

Patrick STODDARD (WD9EWK/VA7EWK) amsat-bb at wd9ewk.net
Sun Sep 27 02:39:35 UTC 2015

Hi Bob!

It is possible that the satellite had another glitch, like
with the passes earlier in the day. I was out for both of
those passes, and heard no FM voice on the 437.200 downlink.
I did copy telemetry on both 437.200 and 437.225, with longer
bursts on the 437.225 beacon than on the 437.200 beacon. I
had one of my tablets with an SDRplay receiver and HDSDR for
the 70cm downlinks, and an IC-2820H for the 2m uplink. Both
of these were connected through a diplexer to my Elk log
periodic. I was able to confirm one thing, despite the lack
of working FM repeater on these two passes... I could
transmit at 50W from the IC-2820H on 144.350 MHz, without
desenssing the SDRplay listening around the 437.200 and
437.225 MHz downlinks. The SDRplay has bandpass filtering
across its entire range, along with the diplexer that would
act as a bandpass filter as well. This is good to see,
confirming that the bandpass filter design in the SDRplay
worked well for that transmit power level (it has been
perfect for the 5W levels I've transmitted on other passes).

I will post the RF recordings from these two passes, with
the telemetry bursts from both downlinks, later tonight. These
recordings are smaller, around 300-350 MB each. I was hoping
that the repeater was on for either - or both - of these passes,
but at least I have an RF recording from each pass. Maybe
someone can take a look at them once I post them, and see if
any usable data can be extracted from them.


Twitter: @WD9EWK

On Sun, Sep 27, 2015 at 2:31 AM, KO6TZ Bob <my.callsign at verizon.net> wrote:

> On the 00:30 and 02:00utc passes 27Sept, nothing heard.
> Is it possible the transponder was only turned on for one pass?

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