Thought these points should be seen be Ten Tec
CW operators, 73, Jim, KH7M:
> >From: Charles W Cotterman <ka8oqf.w8bi@juno.com>
>
> >I've recently learned that trick with both a Yaesu 990 and Icom 751. I
> >don't run the audio full up, just balance the audio level with the rf
> >gain. I tune for sigs with full gain and usually slow agc, then in qso go
> >to fast or no agc and play with the levels. Helps pull things out when
> >conditions get marginal in mid-contact. It's surprising how well you can
> >hear when you're not amplifying the band noise too.
> >
> >Charlie KA8OQF
> >
>
> That't the way I do it with my 75A-4. I run the rf gain down and
> simultaneously increase af gain until I get no further improvement in
> background noise between characters.
>
> The "old way" was necessary for receivers before the days of product
> detectors, when you read cw with the b.f.o. feeding a diode detector. With
> the product detector it is not necessary to reduce the signal level to get
> good demodulation, but the background noise factor is often overlooked.
If
> the rf gain is kept at maximum, during periods of silence as the agc
voltage
> decays, the background noise comes up to the approximate level of the
> desired signal. But with moderate to strong signals reducing the rf gain
> keeps the noise level well below the signal at all times, thus much
quieter
> reception.
>
> Don, K4KYV
--
FAQ on WWW: http://www.contesting.com/tentecfaq.htm
Submissions: tentec@contesting.com
Administrative requests: tentec-REQUEST@contesting.com
Problems: owner-tentec@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|