RadioBanter - View Single Post - Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-Locked AM Product Detector

June 5th 06, 06:24 AM posted to rec.radio.shortwave

Telamon wrote:
In article ,
(Michael Black) wrote:

HFguy ) writes:
Joe Analssandrini wrote:
John Plimmer wrote:

There was also a long thread on this newsgroup that claimed the AOR
7030 had
the best sync detector in the business, but I still punt the R8B as the
7030
sync was NOT sideband selectable, which is required for most good
listening.

Dear John,

Contrary to what you write, the AR7030's synchronous detection circuit
IS most definitely sideband-selectable and features double-sideband
detection as well (so does the Drake R8B). It does not feature a
"fixed" sideband selection as does the Drake R8B (or the Drake
SW8/Grundig Satellit 800), but rather a "variable" one using the
passband tuning. (You can tune the circuit this way as well on the
Drake.)

If your description (above) is technically accurate, the 7030 does not
have a 'real' sideband sync' detector because it requires using the
passband tuning to select the desired sideband in the double-sideband
mode. The sideband sync' detector on the R8B uses phase cancellation for
rejecting the unwanted sideband. This is a more effective rejection
method than using only passband tuning.

But are you arguing semantics, or outcome? Because the phasing method
of selectable sideband reception is not as good as the filter method.
A filter really knocks out the unwanted sideband, while the phasing
method tends to give far less rejection of the unwanted sideband.

It is not a semantics argument. On the R8B you can pick the side band to
listen to and tweak the passband.

Often if I am bother by a heterodyne or splash from an adjacent channel
I can pick the opposite sideband and the interference is GONE. The
AOR7030+ can't do that.

--
Telamon
Ventura, California

When you go for one sideband, you need to select a narrower filter
(technically half the bandwidth). This works just fine on the 7030+,
used with passband tuning. Also, the 7030 VFO is so steady you can pick
USB or LSB, then zero beat it. This works on shortwave, but seems to
add a flutter to AM BCB.

The Sherwood for sale on ebay may not be functional or in good working
shape as it is being sold from a drop off site rather than the user. I
have no problem passing on this sale.