[amsat-bb] LilacSat-2 Ground Interference Resolved (hopefully!)

[Jeff Johns]

That’s some excellent detective work and it’s awesome they worked with you to avoid anymore interference. Good job!

Jeff WE4B

> On Jul 4, 2020, at 6:51 PM, Scott via AMSAT-BB <amsat-bb at amsat.org> wrote:
> 
> Hello everyone.
> 
> By the quirk of the orbital pattern, for several months I've found myself
> at home -and- on the radio during some high, usually weekend evening passes
> of LilacSat-2 (CAS-3H).  Seems like I often get a good pass around 6pm or
> so on the East Coast Fri/Sat/Sun.
> 
> It's bad enough that you never really know when LilacSat-2's FM transponder
> might be active (144.350 up; 437.200 down; no tone), but it seemed like
> every time I did catch it active there would be obvious ground stations
> getting into the uplink.   You could still make contacts, but it was tough
> squeezing in between stations that had no idea they were being
> retransmitted across the entire country.
> 
> I never could catch a call sign, but suspected they might be centrally
> located since the conversations often lasted from AOS to LOS.
> 
> Well, last week I finally got a partial call sign.  After searching on QRZ,
> I thought I might be on the right track & sent an email to Mark, AA0YY.
> Right there on his QRZ page was mention of an AllStar node set to 144.250!
> Not EXACTLY the uplink freq of LilacSat-2, but in the ballpark.  AND, he's
> located in Missouri which is pretty close to the center of the continental
> U.S.
> 
> Mark was super helpful and copied his reply to Dan, KE0OZU, who
> collaborates with him on their AllStar system.  That nailed it.  Dan
> replied that while Mark's AllStar node was on 144.250, it was actually
> Dan's own AllStar node that was set square on 144.350.
> 
> I didn't mention anything to either of them about changing frequency...
> didn't have to.  Dan immediately replied that he would change his system's
> frequency to avoid the conflict with LilacSat-2.
> 
> I've only been around for a couple of passes since Dan made the change, but
> so far no more ground repeater conversations on the uplink.  There's some
> general static noise on LilacSat-2 when no one transmits, but otherwise the
> signal can often be absolutely crystal clear.
> 
> So, only time will tell if that was the ONLY ground repeater getting into
> LilacSat-2's uplink, but hopefully it was an isolated case.  The up/down
> status of the FM Transponder is still a hit or miss proposition, but since
> the other FM sats are often crowded, folks might want to check to see if
> this one is active when you have a high pass.
> 
> -Scott,  K4KDR
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