Re: [amsat-bb] power supply for the down conv.--FREQUENCIES

["Mark L. Hammond" <hammond@xxxxxxxxxxxxxx>]

Hi Jerry,

I just stuck an 8.125 MHz crystal in one of the TranSystem 
downconverters...it seems like I see exactly the same results as you--with 
the variable cap, I could only get within 50 kHz of the "desired 
frequency," meaning it would not tune quite low enough to get the really 
"comfortable" 144=2400.

So I followed your lead and put it so 144.100 = 2400 MHz.  Sounded good to 
me!

I'm wondering if you have any more "on the air experiences" with your 
TranSystem unit(s)?

73,

Mark


At 12:46 PM 3/23/2001, you wrote:
>Art,
>That is very consistant with my tests also (HP signal generator and 
>monitor also).  An unmodified 3733 (after warm up) settled in at 35 kHz 
>higher (2401.00 MHz = 123.035 MHz).  I also took another unit and replaced 
>the 8.98 crystal with a 8.125 ICM (from N0NSV for a Drake) and found the 
>conversion worked perfectly on MMDS compared to my Drake, but was also a 
>little high in freq.  I could not get enough "spread" out of the little 
>vari-cap to get it down to 2400.00 MHz = 144.00 MHz, so I settled for 
>144.100 MHz as being easy to remember.  This is just a plug-in crystal 
>replacement!
>
>I did some comparisons last weekend to my modified Drake 2880 and the 
>TranSystem 3373 performs similarly on local ATV and MMDS.  I did not get a 
>chance to try AO-40, but hope to get to it this weeekend.
>
>Anyone that is interested in these downconverters can contact Bob at 
>K5GNA@aol.com.  He has a "cute" little corner reflector that mounts right 
>on the unit and makes for a nifty all-in-one hand-held S-band 
>downconverter.  I plan to use one with my FT-100 for portable/mobile AO-40 
>mode U/S at the unmodified 123 MHz frequency.
>73,
>Jerry, K5OE


Mark L. Hammond  [N8MH]

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org