Without a preamp, you haven't been hearing the weak ones. Assuming that
your local noise level isn't incredibly high, the stations that sound weak
without a preamp, won't sound weak with it. The stations that sound weak
with the preamp on, are non-existant without it. I've measured the 6M noise
figure and it is about 21 dB without the preamp and 2 dB with it. My preamp
has 26 dB of gain, which is more than I really need. I've added an HP 0-12
dB step attenuator after the preamp to reduce the gain when desired. I
typically see my noise floor drop 8-9 dB when I turn on the preamp (more
when local QRN is minimum). I'm still experimenting with the best
attenuator setting, but I'd say you want at least 16-20 dB of gain.
I own five 6 Meter rigs, and the 5000A is the best by far since I added the
preamp.
73,
Clay W7CE
----- Original Message -----
From: "Dan Eisenman" <k8...@allprophoto.net>
To: <flexradio@flex-radio.biz>
Sent: Saturday, June 20, 2009 10:52 PM
Subject: [Flexradio] Why An Extra Pre Amp On Six Meters
I have been using my 5000A on six meters , seems to work great as is , I
have been
reading about the 3000 not needing a Pre Amp but adding one on the 5000A.
Just curious if any real lab test were run to confirm this data ? The
5000A seems fine to me , I don't seem to have any
trouble hearing and working the weak ones .
73
Dan
K8ICB in Florida
_______________________________________________
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
Knowledge Base: http://kc.flex-radio.com/ Homepage:
http://www.flex-radio.com/
_______________________________________________
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
