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Re: Crying wolf? RS-15



It could be an image frequency, or passband/IF feedthrough.  Both are 
artifacts of your receiver.

A lot of  different "all band" radios share common IF's or passbands.   
Some radios seem to just stick a 10M to VHF converter inline so that you 
could end up hearing weak signals from your allbander on 10M ,even 
though you are on VHF.  Thus, a 10M Rig can end up picking up the 10M 
passband of your all bander when you are transmitting on VHF.

More than likely, you are getting IF or passband  feedthrough and it 
just happens that both radios share a common IF or passband so that one 
will recieve the other when they are near , no matter what band they are 
on.   Try seperating the radios by a few feet and see if the situation 
changes.

Glen



Freeman P. Pascal IV wrote:

>I realize I could be crying wolf here.  If there's an explaination I
>would like to hear it. 
>
>I was tuning around tonight and started listening to RS-15 during it's
>0156-0219 pass across the western United States.  I checked the beacon
>and heard nothing, I tuned up to 29.173 and listened - nothing.
>
>On a whim and a hope, I keyed up and tried to find my downlink.  And to
>my complete surprised found it about 3.5KHz off of where I would have
>expected it if I expected RS-15 to be functional.  
>
>What the heck!  Could RS-15 be working?  I tried CQ'ing for the last ten
>or twelve minutes of the pass until I expected LOS.  The real test would
>be if I could still hear the downlink after LOS.
>
>Unfortunately I could. But oddly only for a couple of minutes, then it
>disappeared.  Could it be that RS-15 was alive and my keps or clock were
>off?  I use NTP to manage my time on my computers so it couldn't be off
>by more than a couple milliseconds.
>
>The uplink and downlink were being adjusted for doppler the whole time. 
>When I adjusted for the offset with my XIT it would act like any other
>satellite transponder.  I even double checked my TX monitor on the
>TS-2000 to make sure it was off - it was.
>
>Was it a harmonic?  My downlink was 29.374, my uplink was 145.880 - this
>gives a harmonic ratio of 4.9663 - very close.
>
>One thing I really can't believe is I that I was able to drop my power
>to 10W and still hear my downlink.  From what I read on the net, I would
>need more power than 10W - considerable more for RS-15.
>
>Unfortunately, it was the last pass of the night for me.  I cant confirm
>one way or the other until the next pass.
>
>Did I just return from a trip from the Twilight Zone?
>
>
>-Freeman, N5FPP
>
>----
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>
>  
>

-- 
Glen E. Gardner, Jr.
AA8C
AMSAT MEMBER 10593
Glen.Gardner@verizon.net


http://members.bellatlantic.net/~vze24qhw/index.html



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