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Re: Drake frequencies



At 04:10 AM 2/14/2001, Edward R. Cole wrote:
>Mark, and...
>
>Look on the cover plate of your Drake.  Mine says Input: 2.5-2.686 GHz,
>Output: 222-408 MHz.  So the LO is Fo-IF = 2278 MHz.  The xtal should be
>2278/256 = 8.8984375 MHz.  If so, then 2.4 GHz would output 122 MHz exactly.
>
>If on the other hand the xtal is Fx = 8.898430 MHz, then Fo = 2277.99808
>and 2.4 GHz would be output at 122.001920 MHz.  Bingo!  That's what you
>have, right?

Right!  Makes sense to me now.

The sad thing was NOT hearing AO-40 today, when it clearly should have been 
in good position/squint (set my alarm for 2am local time to catch the 
pass!).  I think it's my antenna, and/or pointing of my array at 
fault.  Have to check and fix that soon.  I'm in great need of an AO-40 400 
bpsk fix!


>I wonder if you are getting the 16th harmonic from your 150 MHz HT,
>directly.  Or are you driving a diode?

Hrm...since I can't transmit legally on 150 MHz, let's just say I wasn't 
driving a diode.  I was using a 3" rubber dummy load.

>Guess I should power up my unmodified Drake and Generate some 50 MHz RF and
>look for the 48th harmonic.


Let us know how it works out.


>Ain't math fun ;-)
>Ed
>And they gave me a BS in that subject back in the last millenium...figures
>since I'm always BSing ;-)

73,

Mark N8MH

//
 >Okay, I got curious.  I've read that for the stock Drake, 2400=120 MHz, and
> >2400=122 MHz.
> >
> >So--which is it?
> >
> >I inspected my unit (from the group purchase..thanks, Mark :) and the stock
> >crystal in mine is indeed 8.89843.
> >
> >After pointing my array into the shack, I used my HT to xmit on 150.01.  I
> >heard the carrier at 122.152 +/-.  Assuming I am hearing 150.01 X 16
> >(2400.16), this pretty much says for my unit, 2400=122 MHz with the stock
> >crystal.
> >
> >And xmitting on 150.100 (x 16 = 2401.600), I can hear it on 123.589
>(2401.589).
> >
> >I was incorrectly assuming 2400=120MHz this weekend; no wonder I couldn't
> >hear it :)  Boy do I feel better now!
> >
> >73,
> >
> >
> >
> >
> >
> >Mark L. Hammond  [N8MH]
> >


Mark L. Hammond  [N8MH]

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