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uplink frequencies



Rolf, et al

I was seeing a 5Khz error last night (in order to bring my downlink on to 
the frequency I was hearing) from the current figures on amsat-dl and the 
originals from Yoshi. This was using my doppler corrected radio tuner software.

But that error was mine, not the birds.

I think the error is due to believing that UO-11 beacon is at 2401500000. I 
now believe it is as Dominic said at 2401505000. I had calibrated my Local 
Oscillator against UO-11. This gave me a 5Khz offset. I have taken that out 
today. This change puts my AO-40 constant in agreement as 2836990000. I am 
interpreting these frequencies to be the Satellite pass band. Our ground 
frequencies will differ by doppler.

It is interesting what you see when you take out doppler corrections with 
software - like the difference in insertion frequencies for USB vs LSB.  I 
never noticed things like this when I was turning the knobs manually - I 
just assumed it was all doppler.

So for starters, the current published figures look good. Remember that 
uplink doppler is under 5K plus or minus while S Band sees some big numbers 
often 30 to 50Khz. By seeing where the beacon is you can guess the downlink 
doppler, correct your uplink frequency for that and you should be within 
plus or minus 5K (close enough to hear your self.)

Jerry, W6IHG

At 05:57 PM 7/19/01 +0200, Rolf Niefind wrote:
>  Nice to read your story,
>  Brings back very nice memories to OSCAR 10 in August 1986 when I was the 
> only
>European on the bird. No other EU-amateur then had computer predictions 
>and so
>all lost the + 5 degrees elevation angle for europe.
>  Worked about 8 hours from local midnight until breakfast without any break
>
>  What are your corresponding frequencies from 435 up to 2401 down. ?
>  Never have seen measured values !!!
>
>  Here some figures from my LS-Test in May 2001
>
>   1269.322 returned on 2401.378
>   1269.343             2401.357
>   1269.352             2401.347
>   1269.366             2401.334
>   1269.372             2401.327 MHz
>
>   Rolf DK2ZF  JO43VH
>
>   Amsat#493 Amsat-LM-34  ( since 1969)
>
>
>Jerry Pixton schrieb:
> > All,
> >
> > Wow again.  Make 12 contacts last night before going to bed. Was losing my
> > downlink by then (almost 38K). If I had not know where it was (with the
> > Radio Tuner) I would not have found it.
> >
> > I had a wonderful "problem" at the beginning. I could not turn the power
> > down low enough. HI Had the FT-847 all the way down to 3 watts. Thought I
> > would switch polarity on the UHF beam. Guess what? Left hand polarity gave
> > a much stronger signal. Interesting.
> >
> > Now to think about improving the antenna. Have most of the mechanical
> > details thought thru. Waiting on N panel connectors to start 
> experimenting.
> > Have a bunch of helixes sitting on my desk that I wound for practice. 
> Found
> > a little scrap piece of PVC (only 9 inches long) that is thin wall stuff
> > that has good diameter. My constraint is helix has to fit over 1 inch
> > square aluminum tube. Will look at hardware store today to see (of 
> course I
> > don't remember where or why I had thin wall PVC for anything)
> >
> > Thanks to all for my education program.
> >
> > Jerry, W6IHG
> > ------------------------------------------
> > Dr. Jerry R. Pixton, PIXOS Designs LLC
> > http://www.pixos.com/designs/
> > jpixton@shentel.net
> > ------------------------------------------
> >
> > ----
> > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org

------------------------------------------
Dr. Jerry R. Pixton, PIXOS Designs LLC
http://www.pixos.com/designs/
jpixton@shentel.net
------------------------------------------

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