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Old June 4th 06, 07:29 AM posted to rec.radio.shortwave
RHF
 
Posts: n/a
Default Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-Locked AM Product Detector

For One and All,

First of these that I have seen on eBay

Sherwood SE-3 MK III D Synchronous High-Fidelity
Phase-Locked AM Product Detector - Any Good ?

http://cgi.ebay.com/_W0QQitemZ9734932430

What would be better a Drake R8 with the Sherwood SE-3 ?
- - - o r - - -
a Drake R8B using it's own Sync Detector ?

Any one used them both ? {or have an opinion ?}

i want to know ~ RHF
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Old June 4th 06, 09:54 PM posted to rec.radio.shortwave
Joe Analssandrini
 
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Default Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-Locked AM Product Detector

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.)

A good argument could be made that the Drake's sync circuit thus has
more options - but I have found that using the variable selectable
sideband on the AR7030 Plus offers much better control. I should think
the same would apply to the Drake R8B. You will find the sound to be
slightly better and the lock to be somewhat more robust when you tune
this way - you use the passband offset at the minimum distance
necessary away from true center rather than at some "fixed" offset
determined by the factory. (The Drake's circuit will make a low-pitched
noise as you tune this way [the AOR's does not] but when you reach the
desired passband offset, the noise goes away and the sync circuit
stablizes.)

Neither of the circuits, however, are "perfect." The Drake circuit
often "warbles" (my very poor term but you know what I'm talking about)
- especially noticeable on musical notes - as the signal varies in
strength. The AOR circuit "hunts" and momentarily "mutes" as a station
is changed (NOT, however, when using the free RxWINGS computer-control
program). But it then stays "rock-solid" regardless what the signal
subsequently does.

The AR7030's sync circuit does not "struggle" to maintain lock as does
Drake's circuit.

AOR's "shortcoming" has been verified to me as being inherent by
Richard Hillier of AOR-UK. Drake's "shortcoming" has been verified to
me as being inherent by two different service technicians at Drake.

PLEASE NOTE that these so-called "shortcomings" are minor in nature in
the overall scheme of things and should certainly not be blown out of
proportion. Either one of these sync detectors is far better than any
other currently being offered today (with the possible exception of
that Sherwood SE-3, with which I have no experience - though about
which I have read only very good things) and I use both of them - one
on my AR7030 Plus and the other on my Grundig Satellit 800 (which uses
the same circuit as the Drake R8B, the sole control exception being not
offering double-sideband detection).

Of the two, I much prefer AOR's. And note this well - I'd rather have
SOME sync circuit than NO sync circuit!.

Best,

Joe

P.S. to RHF (after all, it's your post!): Sherwood can install a 455
kHz output on your Drake R8B should you wish to incorporate an SE-3.

  #3   Report Post  
Old June 5th 06, 04:10 AM posted to rec.radio.shortwave
Michael Black
 
Posts: n/a
Default Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-Locked AM Product Detector

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.

Michael

  #4   Report Post  
Old June 5th 06, 05:58 AM posted to rec.radio.shortwave
Telamon
 
Posts: n/a
Default Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-Locked AM Product Detector

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
  #5   Report Post  
Old June 5th 06, 06:06 AM posted to rec.radio.shortwave
HFguy
 
Posts: n/a
Default Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-LockedAM Product Detector

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.

Michael


A sync' detector which implements sideband rejection using the
quadrature method (phase shifting) allows the user to select one of two
signals (either sideband) which are 180-deg. out of phase. This is a
more effective way to reject the unwanted sideband of an AM signal than
using *only* passband tuning. In the case of the R8B you can reject the
unwanted sideband much better with the selectable sideband sync' than by
using just the passband tuning. It occurred to me that we may be talking
about different subjects, since you referred to phasing and filtering,
which are two methods of bandwidth selection.


  #6   Report Post  
Old June 5th 06, 06:15 AM posted to rec.radio.shortwave
craigm
 
Posts: n/a
Default Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-Locked AM Product Detector

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.

Michael


Both methods have their limits to unwanted sideband rejection.

For the filtering method, no physical filter has infinitely steep sides, so
closer to carrier, the unwanted sideband rejection can be poor if you do
not want to also lose part of the desired sideband.

For the phasing method, the unwanted sideband rejection is based upon the
accuracy of the phasing network. The better the network, the better the
results.

So, to say one is better than the other is challenging. If you wish to say
one is better than th other, you will need to describe the two specific
implementations in great detail. This must include the characteristics of
the filters and phasing networks over the range of interest. Deetailed
measurements of unwanted sideband rejection vs. frequency would be good to
see.

craigm



  #7   Report Post  
Old June 5th 06, 06:24 AM posted to rec.radio.shortwave
 
Posts: n/a
Default Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-Locked AM Product Detector


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.

  #8   Report Post  
Old June 5th 06, 06:30 AM posted to rec.radio.shortwave
Telamon
 
Posts: n/a
Default Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-Locked AM Product Detector

In article , craigm
wrote:

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.

Michael


Both methods have their limits to unwanted sideband rejection.

For the filtering method, no physical filter has infinitely steep
sides, so closer to carrier, the unwanted sideband rejection can be
poor if you do not want to also lose part of the desired sideband.

For the phasing method, the unwanted sideband rejection is based upon
the accuracy of the phasing network. The better the network, the
better the results.

So, to say one is better than the other is challenging. If you wish
to say one is better than th other, you will need to describe the two
specific implementations in great detail. This must include the
characteristics of the filters and phasing networks over the range of
interest. Deetailed measurements of unwanted sideband rejection vs.
frequency would be good to see.


Like any functional feature in a receiver the effectiveness varies
depending on the reception situation. Sometimes shifting the passband
or selecting the sideband works best. The Drake just has another tool
that the AOR 7030+ does not have and sometimes it make a big difference
other times not.

--
Telamon
Ventura, California
  #9   Report Post  
Old June 5th 06, 06:49 AM posted to rec.radio.shortwave
Telamon
 
Posts: n/a
Default Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-Locked AM Product Detector

In article .com,
wrote:

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.


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.


Usually the passband tuning is all I need to get rid of adjacent channel
interference and the AOR7030+ and Drake R8B both have this ability. A
neat thing the AOR can do is auto notch a heterodyne tone. Additionally
the AOR will track this tone and keep it notched out if it drifts. The
Drake has a manual notch that is pretty sharp. I usually don't have to
do this because moving the passband usually solves the problem but I
have had the situation where I have splash on one side a heterodyne tone
from another station on the other sideband so both functions are needed.

The AOR 7030+ can auto tune itself to a station and maintains lock on it
without intervention and it has the auto notch feature the Drake does
not have where the Drake has the sideband selectable sync.

Every radio has its pluses and minuses and will work better in some
situations, is easier to use, or sound better than other radios.

--
Telamon
Ventura, California
  #10   Report Post  
Old June 5th 06, 06:53 AM posted to rec.radio.shortwave
 
Posts: n/a
Default Sherwood SE-3 MK III D Synchronous High-Fidelity Phase-Locked AM Product Detector


Telamon wrote:
In article .com,
wrote:

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.


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.


Usually the passband tuning is all I need to get rid of adjacent channel
interference and the AOR7030+ and Drake R8B both have this ability. A
neat thing the AOR can do is auto notch a heterodyne tone. Additionally
the AOR will track this tone and keep it notched out if it drifts. The
Drake has a manual notch that is pretty sharp. I usually don't have to
do this because moving the passband usually solves the problem but I
have had the situation where I have splash on one side a heterodyne tone
from another station on the other sideband so both functions are needed.

The AOR 7030+ can auto tune itself to a station and maintains lock on it
without intervention and it has the auto notch feature the Drake does
not have where the Drake has the sideband selectable sync.

Every radio has its pluses and minuses and will work better in some
situations, is easier to use, or sound better than other radios.

--
Telamon
Ventura, California


I use the notch filter quite often, but unless things have changed, it
was an option on the radio. By the time you outfit a 7030 with all the
goodies, it costs much more than the Drake R8B did. I never found the
noise blanker to be all that useful on the 7030, but it might just be
me.

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