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Re: AO16 and other stuff

Hi Bill

I think the stuff you heard was not Cell phone but 2.4 GHz cordless
phone. With a 25 turn helix and a DEM LN preamp and RX converter 
I have heard them from over a mile away.  A block away 
they will pin the S meter on FM.  On SSB it sounds like bursts of
noise.  Depending on the model they have from 20 to 30 auto 
select channels with the lowest channel just above 2400. Those that
I have monitored use freq hopping and are about 6 MHz wide. As you
have found out if you tune to one of the many signal peaks you can
readily copy them on FM.  Other signals I have heard, but above
the AO-40 freq, are LAN transmissions.  I have heard them at about
S7 eminating from a business tower building a kilometer away. 
I believe that cordless phones that use 2.4 GHz, (some 900 MHz
types work cross band with 900 for the handset and 2.4 for the 
base) may be a real problem for AO-40 reception in urban areas.  

Clare VE3NPC

>Found out some other interesting stuff as well. I was having some
>popping type noise intermittantly on the Drake and I thought it was the
>fact that I didn't have the inductor on the input. When I put up the
>Trans convertor I was having a similiar effect. I was in CW mode on the
>736. I switched to FM mode and what do I hear but a Cell phone
>conversation loud and clear. It was very wide on the deviation. Looks
>like some of the noise stuff might be Cell harmonics. I have a cell site
>about 1 mile from my QTH. If anyone else is having this noise problem
>try switching to FM mode and see if you hear Cell stuff. I hooked the
>Spectrum Analyzer to the convertor and I could see the Cell site nice a
>strong right in the middel of the Ham band.
>73 Bill WA2TQI
>Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
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