[amsat-bb] AO-07 Popularity?

[Scott]

>>>Where is the sweet spot?

The link below is a screen shot that I took one day back in March when a 
strong CW signal killed the transponder on AO-7.  Before the 2m downlink 
went offline you can see the three places that I believe people are 
referring to.

Looks to me like 145.928, 145.943, & 145.959, more or less.

Here's that image:

https://www.dropbox.com/s/ztffqf1afwdmrt0/screen.png?raw=1


I have vastly less experience on the linear transponders than most, but here 
are a couple of things I've noticed repeatedly that might be helpful on 
AO-7.

#1, there is a LOT of difference in downlink signal strength from one pass 
to the next.  So, if you hear little or no traffic on the transponder, it's 
not necessarily anything you are doing wrong.

#2, don't overlook the low-elevation period at the beginning or end of a 
pass.  I've often noticed downlink signals 2 or 3 times stronger on AO-7 
just after AOS and just before LOS.

#3, it's a shared resource.  So, if you see (on an SDR waterfall) or hear 
another station with an extremely strong signal, it might be worth waiting 
to transmit until they stop -- your signal will probably be much more 
effective

#4, I've noticed that when I take off my headphones and stop the recorder, 
signals instantly jump to max scale!  If you can perfect a move where you 
FAKE taking off your headphones and only PRETEND to stop the recorder, you 
might have a shot at some of the best audio you've heard via satellite.

-Scott,  K4KDR

=====================================

----Original Message----- 
From: Doug Phelps via AMSAT-BB
Sent: Saturday, September 21, 2019 2:20 PM
To: wb1fj-bb at fisher.cc ; james at thirdglance.com
Cc: amsat-bb at amsat.org
Subject: Re: [amsat-bb] AO-07 Popularity?

Where is the sweet spot?

=====================================

-------- Original Message --------
On Sep 10, 2019, 11:37 AM, Burns Fisher via AMSAT-BB wrote:

> AO-7 also works best in a small sweet spot in its passband. If you don't
> know that it can be frustrating to hear yourself all garbled. All that
> said, I think most linears have relatively low use. What is your
> experience in Australia with the XW satellites (which work absolutely
> great!)?
>
> On Tue, Sep 10, 2019 at 8:24 AM James Pierce via AMSAT-BB <
> amsat-bb at amsat.org> wrote:
>
>> I’ve put out calls a number of times on AO-07 as it passes over Australia
>> and while I hear my own single back clearly I’ve never had a reply. I
>> guess I’m curious if there is a calling protocol I’m missing, or a
>> particular part of the passband etc? As a higher altitude bird with great
>> coverage it would seems logical to me that it would be popular? Am I
>> missing something?
>>
>> James.