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Re: Drake frequencies

2400MHz -> 120 MHz...

I don't know what rig you have, but most modern rigs will tune there.  My 
FT-847 will, and in sat mode. (and sat mode works at 50 MHz too...)

The if mods with the 22 pf Caps may need to be increased to, say,
27 pf to work at 120 MHz optimally-- as the peak gain on my converter is 
around 153 MHz or so with the 22 pf mods..

120 MHz is in the "protected" aircraft band, so it is a quiet band
to start off with.  I also have kicked around the idea of using
a 70 MHz clock osc to mix down to 50 MHz as an IF... therefore
all IFs (the 120 and 50) should be far enough away from 144 for mode-L 
uplink (2m->1269 transmit converter I have) and for 432 for mode-U uplink.  
To me, it makes more sense NOT to change the xtal, unless
your rigs will not tune out of band.  The transmit protection is good
too (though I am a MARS op, so my rig is opened up.. so for me that
possibility still exists..)

If you don't think you need to change the XTAL, don't.. you'll save about 
$20 too..

Fred W0FMS

>From: Floyd Rodgers <kc5qbc@swbell.net>
>To: amsat-bb@AMSAT.Org
>Subject: [amsat-bb] Drake frequencies
>Date: Tue, 13 Feb 2001 11:13:53 -0600
>What is the output frequency of the unmodified Drake as related to AO40
>downlink frequency?
>Why should I modify the drake output frequency to be in the trasmitter
>output rage (i.e. 144mhz) ? If drake downlink freqency is outside the
>normal transmit range, the radio will protect the converter by not
>transmitting out of band. I assume then the uplink signal would be sent
>from the 432 side of the same radio or another separate radio via 
>Floyd Rodgers KC5QBC
>Multi ended candle burning artist in training
>Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org

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