[amsat-bb] Re: drake 2880
kl7uw at acsalaska.net
Wed Feb 24 00:27:15 PST 2010
At 02:26 PM 2/23/2010, Jim wrote:
>Has any one used the Drake 2880 downconverter on the air.
>I have 2 of them 1 I did the mod on and one that has not has any thing done
>Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the author.
>Not an AMSAT-NA member? Join now to support the amateur satellite program!
>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
I have two Drakes that were used on AO-40. One is converted to
435-MHz IF and the second unmodified runs with 123-MHz IF. I feed
both with a MKU-232A2 preamp directly connected to a 6-1/4 turn
helical feed in front of a 85cm (33-in) offset feed dish. I have not
re-installed my Drakes but the dish/preamp are ready for use.
The Drakes do not have very good noise figure (~7 dB) so a low-noise
preamp is mandatory. The db6nt preamp has 0.6 dBNF with 40-dB gain,
easily able to feed both Drakes thru a coaxial tee.
I also have a DEMI 2400-MHz preamp which I am thinking of feeding
with a patch antenna. I am thinking that the patch should provide
ample gain for S-band Leo satellites. The two antenna/preamps will
be connected to the Drakes via a cross-over relay (not yet installed).
I will need auto-tracking/tuning for S-band operation on Leo's.
73, Ed - KL7UW, WD2XSH/45
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
500-KHz/CW, 144-MHz EME, 1296-MHz EME
DUBUS Magazine USA Rep dubususa at hotmail.com
More information about the AMSAT-BB