On Fri, 16 May 2008, Scott Dorsey wrote:

Richard Knoppow wrote:
It seems to me that it should not be too difficult to
design one that is superior to the old vacuum tube models.
There are certainly plenty of receivers out there which
could use an adaptor. Have you any definite ideas about
price range, features, etc?

What I was thinking was to take the AM synchronous detector circuit from
OH2GF which was published in the July '93 QST issue. It is based on an
NE602 which does not have the best dynamic range in the world but seems to
be okay.

A slicer by definition has selectible sideband, and maybe specifically
uses phasing to get it.

They existed at a time when there wasn't much but AM radios, so to get
around the "turn down the RF gain, turn up the AF gain and turn on the
BFO" you needed to add a product detector. Once you were doing that,
you might as well add selectable sideband via phasing, since it didn't
add that much to the cost, but did help improve things when the receiver's
IF was wide for AM.

It lives on today, since most "low end" shortwave receivers that have
synchronous detector uses the phasing method to increse performance
without the cost of an actual better IF filter.

There were external SSB adaptors that included an IF filter for SSB,
but I can't think of seeing any that called themselves "slicers".

Michael VE2BVW

I was first going to make up a PC board layout rather than constructing it
dead-bug style like the original, then I was going to try one of the new
Maxim detector chips in place of the NE602, but retaining the NE804 limiter
and phase detector.

If I were going to do it with tubes, I would look into some of the sheet
beam tubes that were intended for TV chroma detector circuits... many of
them have excellent performance and are very inexpensive (as are all old
TV tubes). The 7360 costs a bloody fortune when you can find one, but
the 6AR8, 6JM8, and 6ME8 are effectively the same basic design but with
less crosstalk.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Michael Black" wrote in message
mple.org...
On Fri, 16 May 2008, Scott Dorsey wrote:

Richard Knoppow wrote:
It seems to me that it should not be too difficult
to
design one that is superior to the old vacuum tube
models.
There are certainly plenty of receivers out there which
could use an adaptor. Have you any definite ideas about
price range, features, etc?

What I was thinking was to take the AM synchronous
detector circuit from
OH2GF which was published in the July '93 QST issue. It
is based on an
NE602 which does not have the best dynamic range in the
world but seems to
be okay.

A slicer by definition has selectible sideband, and maybe
specifically uses phasing to get it.

They existed at a time when there wasn't much but AM
radios, so to get
around the "turn down the RF gain, turn up the AF gain and
turn on the
BFO" you needed to add a product detector. Once you were
doing that,
you might as well add selectable sideband via phasing,
since it didn't
add that much to the cost, but did help improve things
when the receiver's
IF was wide for AM.

It lives on today, since most "low end" shortwave
receivers that have
synchronous detector uses the phasing method to increse
performance
without the cost of an actual better IF filter.

There were external SSB adaptors that included an IF
filter for SSB,
but I can't think of seeing any that called themselves
"slicers".

Michael VE2BVW

I was first going to make up a PC board layout rather
than constructing it
dead-bug style like the original, then I was going to try
one of the new
Maxim detector chips in place of the NE602, but retaining
the NE804 limiter
and phase detector.

If I were going to do it with tubes, I would look into
some of the sheet
beam tubes that were intended for TV chroma detector
circuits... many of
them have excellent performance and are very inexpensive
(as are all old
TV tubes). The 7360 costs a bloody fortune when you can
find one, but
the 6AR8, 6JM8, and 6ME8 are effectively the same basic
design but with
less crosstalk.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

I am not sure how a synchonous detector works with
suppressed carrier SSB but my understanding of it may be
incorrect. To me a synchronous detector is a device for
replacing the carrier of a double sideband signal, either AM
or suppressed carrier and synchronized by means of the equal
and opposite phase of the two sidebands. Such a detector
will supply a locally generated carrier which has exactly
the right phase with relation to the sidebands even when
they are distorted by selective fading. Similar detectors
are also used for television where there is a residual
carrier and sideband since that is enough to lock the
oscillator to the correct frequency and phase.
Beam switching tubes were used to some extent in
commercial vacuum tube equipment but Hallicrafters
transmitters are the only example with come to mind at the
moment, I am sure there were others. These things came along
at about the same time that transistors began to supplant
tubes.

As far as selectable sideband in an SSB adaptor AFAIK
all worked by means of either shifting the signal to the
filter frequency or having two filters. I don't see how
phasing would work in a receiving adaptor. There were
numerous phasing type SSB generator for transmitting, for
instance the one made by Barker and Williamson who also made
90degree audio phase shifting networks for use in home made
ones. I still have the B&W adaptor I used in the 1960s. It
worked pretty well but had to be adjusted for any large
frequency change. Stable high performance filters or
reasonable cost pretty much ended the use of phasing type
exciters.

In any case, a good performing receiving adaptor which
would work on older receivers, especially tube receivers,
would be welcome. The old Hammarlund and TMC units are
pretty hard to come by and, I suspect, something modern
would outperform them.


--
---
Richard Knoppow
Los Angeles, CA, USA

WB6KBL

"Richard Knoppow" wrote in message
m...
As far as selectable sideband in an SSB adaptor AFAIK all worked by
means of either shifting the signal to the filter frequency or having two
filters. I don't see how phasing would work in a receiving adaptor. There
were numerous phasing type SSB generator for transmitting, for instance
the one made by Barker and Williamson who also made 90degree audio phase
shifting networks for use in home made ones. I still have the B&W adaptor
I used in the 1960s. It worked pretty well but had to be adjusted for any
large frequency change. Stable high performance filters or reasonable cost
pretty much ended the use of phasing type exciters.

In any case, a good performing receiving adaptor which would work on
older receivers, especially tube receivers, would be welcome. The old
Hammarlund and TMC units are pretty hard to come by and, I suspect,
something modern would outperform them.


--
---
Richard Knoppow
Los Angeles, CA, USA

WB6KBL


The Central Electronic Sideband Slicer used phasing for SSB reception.

On the other hand, the B&W 370 used the filter method.

Pete

"Tio Pedro" wrote in message
...

"Richard Knoppow" wrote in
message
m...
As far as selectable sideband in an SSB adaptor
AFAIK all worked by means of either shifting the signal
to the filter frequency or having two filters. I don't
see how phasing would work in a receiving adaptor. There
were numerous phasing type SSB generator for
transmitting, for instance the one made by Barker and
Williamson who also made 90degree audio phase shifting
networks for use in home made ones. I still have the B&W
adaptor I used in the 1960s. It worked pretty well but
had to be adjusted for any large frequency change. Stable
high performance filters or reasonable cost pretty much
ended the use of phasing type exciters.

In any case, a good performing receiving adaptor
which would work on older receivers, especially tube
receivers, would be welcome. The old Hammarlund and TMC
units are pretty hard to come by and, I suspect,
something modern would outperform them.


--
---
Richard Knoppow
Los Angeles, CA, USA

WB6KBL


The Central Electronic Sideband Slicer used phasing for
SSB reception.

On the other hand, the B&W 370 used the filter method.

Pete
I found the handbook for the CE box on BAMA and will have
a look at what they are doing.


--
---
Richard Knoppow
Los Angeles, CA, USA

Richard Knoppow wrote:
I found the handbook for the CE box on BAMA and will have
a look at what they are doing.


Hi,

The Central Electronics Slicer was based on the GE Signal Slicer,
which appeared in GE Ham News, July-Aug 1951.

BANA has the issue, under the category gehamnews, filename ge0604.pdf

The GE article shows how to build it, including the the 90 degree
audio phase shift network. It's pretty slick -
a selectable sideband adapter based on a phase shifting circuit,
for any 450kc to 500kc i.f. receiver.

73,
Ed Knobloch

The reason I said either slicer or ssb adapter is as follows:

A slicer allows one to copy and select the sideband
on an older receiver such as the Hammarlund 129X.
The most prominent slicer was amde by Central Electronics there were two
versions, one just a slicer and another with a Q Multiplier which was
usually missing from older receivers. There were several other slicers on
the market. I had one called a VR
made in New England. RME made one to match the 4300/4350 receivers. This
was the only one that did not match 455 kcs IF's.

The best example of the ssb adapter was the Hammarlund HC-10 which added
another IF plus a slot and pass band filter. The SPC-10 was exactly the
same except sold to the DOD for six times as much as the HC-10. Frank
Lester (SK) designed these and helped incorporate them into several of the
Hammarlund receivers. TMC and several others made ssb adapters, too.

Both the slicer and SSB adapters made copying CW better too.

Dave K4JRB and still looking!

"David Thompson" wrote in message
...
The reason I said either slicer or ssb adapter is as follows:

A slicer allows one to copy and select the sideband
on an older receiver such as the Hammarlund 129X.
The most prominent slicer was amde by Central Electronics there were two
versions, one just a slicer and another with a Q Multiplier which was
usually missing from older receivers. There were several other slicers on
the market. I had one called a VR
made in New England. RME made one to match the 4300/4350 receivers. This
was the only one that did not match 455 kcs IF's.

The best example of the ssb adapter was the Hammarlund HC-10 which added
another IF plus a slot and pass band filter. The SPC-10 was exactly the
same except sold to the DOD for six times as much as the HC-10. Frank
Lester (SK) designed these and helped incorporate them into several of the
Hammarlund receivers. TMC and several others made ssb adapters, too.

Both the slicer and SSB adapters made copying CW better too.

Dave K4JRB and still looking!



The B&W 370 includes a SSB crystal filter.

My RME 4350 has a 455 kc if. Never owned the 4301, but expect it would have
taken the output after the 455 kc conversion.

73, Colin K7FM

"Edward Knobloch" wrote in message
news:KmoYj.505$ju1.354@trndny06...
Richard Knoppow wrote:
I found the handbook for the CE box on BAMA and will
have a look at what they are doing.


Hi,

The Central Electronics Slicer was based on the GE Signal
Slicer,
which appeared in GE Ham News, July-Aug 1951.

BANA has the issue, under the category gehamnews,
filename ge0604.pdf

The GE article shows how to build it, including the the 90
degree
audio phase shift network. It's pretty slick -
a selectable sideband adapter based on a phase shifting
circuit,
for any 450kc to 500kc i.f. receiver.

73,
Ed Knobloch


I have the full set of GE Ham News from the web so I'll
look for it. One of the patents is from R.B.Dome and was one
of those for the Dome stereo system for FM.


--
---
Richard Knoppow
Los Angeles, CA, USA

"Edward Knobloch" wrote in message
news:KmoYj.505$ju1.354@trndny06...
Richard Knoppow wrote:
I found the handbook for the CE box on BAMA and will
have a look at what they are doing.


Hi,

The Central Electronics Slicer was based on the GE Signal
Slicer,
which appeared in GE Ham News, July-Aug 1951.

BANA has the issue, under the category gehamnews,
filename ge0604.pdf

The GE article shows how to build it, including the the 90
degree
audio phase shift network. It's pretty slick -
a selectable sideband adapter based on a phase shifting
circuit,
for any 450kc to 500kc i.f. receiver.

73,
Ed Knobloch

I printed this out. The GE treatment is much more
informative than the CE handbook and the schematic is drawn
in a less confusing way.
This issue of GE Ham News does not have details of the
90degree network, it refers to an earlier edition which has
an artical on building a phasing type transmitting SSB
generator. That one does not appear to be on-line, at least
not on the BAMA site.
Its interesting to me that General Electric was hep to
SSB for ham use in about 1950 when it was still quite a
novelty. Of course SSB goes back into the 1930's for
commercial purposes, maybe even earlier. I don't remember
when AT&T began to use it for their transoceanic telephone
service.


--
---
Richard Knoppow
Los Angeles, CA, USA