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December 18th 05, 03:27 AM posted to rec.radio.shortwave

On Fri, 16 Dec 2005 22:46:30 GMT, (Mark Zenier)
wrote:

In article ,
Telamon wrote:
In article R_4of.4765$Kk7.1619@trndny05, HFguy
wrote:

The sync' detector on my R8B never growls during an extreme fade. It
stays locked. It also does DSB in addition to LSB or USB.

wrote:
The 7030 sync is a bit more versitile that that on the R8B. You can
even do DSB reception, or any mixture of LSB and USB. It's hard to
explain unless you have used one. However, the Drake gives you more
bang for the buck, especially with the weak dollar.

We did the test during the day, which is pretty difficult for
shortwave. The nice thing about the 7030 sync is it never growled
during extreme fading.

I see someone else wrote the above and responding to the comment that
the 7030+ sync is more flexible than the Drake R8B is wrong. The Drake
has selectable sideband sync and the 7030+ does not have this function.
Both radios have sync and you can adjust the passband on both but only
the Drake can sync to one sideband or the other. The result is the
blocking is better on the Drake since you can move the passband and
select the side band with the least interference.

So, what's the acoustic difference between using 1) an image reject
mixer and a broad IF filter and 2) using any sort of product detector
and a narrower IF filter?

going to depend upon where the AGC signal is developed.

The bind with a broad IF filter that is upwind of AGC generation is
you can develop AGC from signals in the passband that are ignored by
the product detector, and effectively reduce receiver performance. You
almost always want a narrow IF filter upwind of AGC generation to
avoid that problem.

A sideband is a sideband. If the unwanted sideband is xx dB down
from the desired signal, does it matter how it's done?

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)