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I am working on restoring an S-38E and would appreciate a clear reworked copy of its schematic diagram. ?I have found some scanned copies but none are clear enough to read all of the component values and wiring connections.
Thank you all in advance.
--
Glen Jenkins, WB4KTF, S-38E
wb4ktf@...
|
Glen - This one isn't too bad...
73,
Justin B. - KI5GKD
On 10/25/2024 5:48 PM, Glen Jenkins
WB4KTF wrote:
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I am working on restoring an S-38E and would appreciate a
clear reworked copy of its schematic diagram. ?I have found some
scanned copies but none are clear enough to read all of the
component values and wiring connections.
Thank you all in advance.
--
Glen Jenkins, WB4KTF, S-38E
--
Justin B.
KI5GKD
|
https://bama.edebris.com/manuals/hallicra/ ? Gary H. Harmon Jr 6003 Archwood San Antonio, TX 78239-1504 (210) 657-1549 home (210) 884-6926 cell gharmon@... k5jwkgary@... ?
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From: [email protected] < [email protected]> On Behalf Of Justin Bowser - KI5GKD via groups.io Sent: Friday, October 25, 2024 11:01 PM To: [email protected]Subject: Re: [HallicraftersRadios] Wanted: Schematic for S-38E ? Glen - This one isn't too bad... 73, Justin B. - KI5GKD On 10/25/2024 5:48 PM, Glen Jenkins WB4KTF wrote: I am working on restoring an S-38E and would appreciate a clear reworked copy of its schematic diagram. ?I have found some scanned copies but none are clear enough to read all of the component values and wiring connections. Thank you all in advance. Glen Jenkins, WB4KTF, S-38E
--
Justin B.
KI5GKD
|
This looks like one from BAMA. The S-38C one is pretty good, at
least readable but the Mark 2 and 3 book is pretty blurry. I looked
through the stuff I have archived but could not find a really good copy.
Note that C-29 and C-30, the feedback caps for the regenerative BFO
are not identified in the parts list. In other S-38 versions these are
"gimmick" caps consisting of twisted wires or just stray coupling. The
regeneration is set to be just past the point of oscillation. This
narrows the IF passband, making it somewhat more selective for CW and
provides a BFO. It should be set just the point of oscillation so as not
to broaden out the IF again. On very late versions there is a pot to
control the regeneration. Of course, the original S-38 has an actual
separate BFO but this arrangement does narrow the selectivity a bit
while eliminating a tube.
My first short wave receiver was an S-38B, sadly accidentally sold
with a bunch of junk in storage. I have a fondness for the series.
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On 10/25/2024 9:01 PM, Justin Bowser - KI5GKD wrote: Glen - This one isn't too bad...
73,
Justin B. - KI5GKD
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Justin,
Thank you.
--
Glen Jenkins, WB4KTF, S-38E
|
Hi Gary,
I also just added a DJVU reader so that I could use these BAMA files, all went OK.
We just left San Antonio this morning after a super evening at the ALAMODOME seeing Billy Joel and Sting.
Thanks for the link
On Fri, Oct 25, 2024 at 11:19 PM, Gary Harmon wrote:
https://bama.edebris.com/manuals/hallicra/
?
--
Glen Jenkins, WB4KTF, S-38E, Austin, TX
|
Glad to help Glen.? My daughter in law and granddaughter were there also. ? Best 73, ? Gary H. Harmon Jr 6003 Archwood San Antonio, TX 78239-1504 (210) 657-1549 home (210) 884-6926 cell gharmon@... k5jwkgary@... ?
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From: [email protected] < [email protected]> On Behalf Of Glen Jenkins WB4KTF via groups.io Sent: Saturday, October 26, 2024 3:54 PM To: [email protected]Subject: Re: [HallicraftersRadios] Wanted: Schematic for S-38E ? I also just added a DJVU reader so that I could use these BAMA files, all went OK. We just left San Antonio this morning after a super evening at the ALAMODOME seeing Billy Joel and Sting. On Fri, Oct 25, 2024 at 11:19 PM, Gary Harmon wrote: Glen Jenkins, WB4KTF, S-38E, Austin, TX
|
A note: looking at the various handbooks for the E version I find a
major difference in the first E and the Mark1 and 2 versions, namely the
arrangement of the BFO. In the first one an arrangement similar to that
used in the B is found, namely stray capacitance in the form of gimmick
wires are used to cause the IF amplifier to oscillate as a regenerator.
In the later version a pot is inserted in the suppressor grid of the IF
amp to control its gain and cause it to act as a regenerator. This will
also affect its selectivity. The control is on the back apron of the
receiver so it can be adjusted at will. The pot is listed in the parts
list. The schematic from BAMA for this series is pretty bad. I don't
have a better.
I find it interesting that Hallicrafters engineers took so long to
figure out the adjustable regenerator set up. The original S-38 has a
separate BFO of the conventional sort, with a diode in the tube acting
as a noise limiter. The B version eliminates the separate BFO and makes
the IF stage oscillate through capacitive coupling. This eliminates the
additional tube. Evidently, with the second E version they went to the
idea of making the if into a regenerative detector. This provides a beat
oscillator but it also can be used to narrow the bandwidth of the IF by
careful adjustment of the BFO control. Still gets rid of the extra tube
but, of course, sill eliminates the noise limiter.
The B type circuit can still be adjusted for best selectivity but
its a matter of moving wires so, once done its pretty much fixed.
Its interesting to me that Hallicrafters kept tinkering with the
design of many of its receivers.
toggle quoted message
Show quoted text
On 10/25/2024 3:48 PM, Glen Jenkins WB4KTF wrote: I am working on restoring an S-38E and would appreciate a clear reworked
copy of its schematic diagram. ?I have found some scanned copies but
none are clear enough to read all of the component values and wiring
connections.
Thank you all in advance.
--
Glen Jenkins, WB4KTF, S-38E
wb4ktf@...
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
So Glen first needs to find out which version he has? ??? on bama is clear , another manual isn’t ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Saturday, October 26, 2024 8:47 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Wanted: Schematic for S-38E? A note: looking at the various handbooks for the E version I find a
major difference in the first E and the Mark1 and 2 versions, namely the
arrangement of the BFO. In the first one an arrangement similar to that
used in the B is found, namely stray capacitance in the form of gimmick
wires are used to cause the IF amplifier to oscillate as a regenerator.
In the later version a pot is inserted in the suppressor grid of the IF
amp to control its gain and cause it to act as a regenerator. This will
also affect its selectivity. The control is on the back apron of the
receiver so it can be adjusted at will. The pot is listed in the parts
list. The schematic from BAMA for this series is pretty bad. I don't
have a better.
I find it interesting that Hallicrafters engineers took so long to
figure out the adjustable regenerator set up. The original S-38 has a
separate BFO of the conventional sort, with a diode in the tube acting
as a noise limiter. The B version eliminates the separate BFO and makes
the IF stage oscillate through capacitive coupling. This eliminates the
additional tube. Evidently, with the second E version they went to the
idea of making the if into a regenerative detector. This provides a beat
oscillator but it also can be used to narrow the bandwidth of the IF by
careful adjustment of the BFO control. Still gets rid of the extra tube
but, of course, sill eliminates the noise limiter.
The B type circuit can still be adjusted for best selectivity but
its a matter of moving wires so, once done its pretty much fixed.
Its interesting to me that Hallicrafters kept tinkering with the
design of many of its receivers.
On 10/25/2024 3:48 PM, Glen Jenkins WB4KTF wrote: I am working on restoring an S-38E and would appreciate a clear reworked
copy of its schematic diagram. ?I have found some scanned copies but
none are clear enough to read all of the component values and wiring
connections.
Thank you all in advance.
--
Glen Jenkins, WB4KTF, S-38E
wb4ktf@...
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
? -- don??? va3drl
|
Would help to know the version. However, it appears that the first E
does not have the adjustment on the back panel. not sure what the
difference between the Mark 1 and Mark 2 are but both are in the later
manual. There are probably marks stamped on the chassis somewhere.
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On 10/26/2024 6:21 PM, don Root wrote: So Glen first needs to find out which version he has?
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
“the adjustment” ??means a pot or?? , I might look later at BAMA. ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Saturday, October 26, 2024 10:54 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Wanted: Schematic for S-38E? Would help to know the version. However, it appears that the first E
does not have the adjustment on the back panel. not sure what the
difference between the Mark 1 and Mark 2 are but both are in the later
manual. There are probably marks stamped on the chassis somewhere.
On 10/26/2024 6:21 PM, don Root wrote: So Glen first needs to find out which version he has? --
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998 -- don??? va3drl
|
My experience with Hallicrafters is to keep things wired "as is"
when working on Hallicrafters if the receiver was never tampered
or worked on in later years.?
I'd keep the resistor values the same too? as Hallicrafters
seemed to use the closest values at hand at the time of
construction.? When re-capping and replacing resistors, why worry
about version?
The alignment instructions will stay the same anyway.?? Keeping
things the same will minimize mistakes and problems.
Lee, w0vt
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?
Would help to know the version. However, it
appears that the first E
does not have the adjustment on the back panel. not sure what
the
difference between the Mark 1 and Mark 2 are but both are in
the later
manual. There are probably marks stamped on the chassis
somewhere.
On 10/26/2024 6:21 PM, don Root wrote:
So Glen first needs to find out which
version he has?
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
--
don??? va3drl
|
Hello Don and others,
I have a S-38E Mark 2 and it has the rear mounted potentiometer.
I also just received the Haystack capacitor kit and will install these.? Ill FIRST change out the AC wiring to correctly wire the Neutral to the chassis instead of the HOT/LINE on the chassis.
How did the Hallicrafter's engineers EVER decide to make the chassis HOT!
--
Glen Jenkins, WB4KTF, S-38E
|
Don,
The link to BAMA site for the Mark 2 page, that I had not found earlier, does have a very nice .jpg image of the re-worked and cleaned up schematic.?
I'll get that one printed out large for use.
This is what I've been looking for.? So THANK you very much for pointing me to it.
BTW, I do have a small 100KHz-crystal Calibrator that I will "mount" inside the receiver, but make it easily removeable once the receiver is working to specification.
--
Glen Jenkins, WB4KTF, S-38E
Austin, TX
|
Thanks for that info Glen Please note that my comments here might sound a bit snarky, but are well intended, and come from my own bad assumptions. RE “How did the Hallicrafter's engineers EVER decide to make the chassis HOT!” Did you read the schematic drawing completely? How do you know which wire from the plug is HOT? Where do you see that the chassis is HOT for either case of plug in the wall? Are you making assumptions based on previous S-38’s.? ? I probably agree in general simple terms with what you are thinking, but not what you actually said. PS “we” have been thru this before. what do they say “measure 3 times and cut once”. I will certainly clarify later if you do not see what my questions are getting at, and again its well intentioned Glen
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From: [email protected] [mailto:[email protected]] On Behalf Of Glen Jenkins WB4KTF
Sent: Sunday, October 27, 2024 4:32 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Wanted: Schematic for S-38E? I have a S-38E Mark 2 and it has the rear mounted potentiometer. I also just received the Haystack capacitor kit and will install these.? Ill FIRST change out the AC wiring to correctly wire the Neutral to the chassis instead of the HOT/LINE on the chassis. How did the Hallicrafter's engineers EVER decide to make the chassis HOT! Glen Jenkins, WB4KTF, S-38E -- don??? va3drl
|
Chassis is not hot.? Neutral and hot are floating.? No
transformer to keep cost down.? You may have some AC on the
chassis due to leaking capacitors.
Lee, w0vt
On 10/27/2024 3:32 PM, Glen Jenkins
WB4KTF wrote:
toggle quoted message
Show quoted text
Hello Don and others,
I have a S-38E Mark 2 and it has the rear mounted
potentiometer.
I also just received the Haystack capacitor kit and will
install these.? Ill FIRST change out the AC wiring to correctly
wire the Neutral to the chassis instead of the HOT/LINE on the
chassis.
How did the Hallicrafter's engineers EVER decide to make the
chassis HOT!
--
Glen Jenkins, WB4KTF, S-38E
|
On some S-38 versions the chassis is hot, used as the B- return but
in all the cabinet is NOT hot. In earlier versions the chassis is
isolated from the cabinet by mounting it and switches, etc, on
insulators. In later versions, the B- return is wired separately from
the chassis, so neither chassis nor cabinet is hot. I have forgotten
where this change was made and am too lazy to look at the schematics. In
any case, Hallicrafters went to some trouble to eliminate shock hazard.
You can sometimes feel a slight sort of vibration on the surface of
the cabinet. This is due to the cabinet having a little AC on it through
the bypass caps used to connect the cabinet at RF in order for it to be
a shield. These are very small caps but do pass some 60Hz, enough to
produce a sensation when running your fingers over the surface. Not
dangerous. However, the cap or caps (usually two) should be checked for
condition. I believe they are ceramics.
If you connect the third wire to the chassis in sets that use the
chassis for B- you will short the supply, not a good idea.
One effect of the AC/DC supply is that reversing the line plug can
affect the residual hum. Should be connected for minimum hum, as noted
in the instruction book.
The versions with separate B- wiring are probably safer than the
others, I wonder if the wiring or the insulatatos of the earlier models
was more expensive to build. Hallicrafters re-design is often quite
innovative, perhaps new engineers.
toggle quoted message
Show quoted text
On 10/27/2024 1:32 PM, Glen Jenkins WB4KTF wrote: Hello Don and others,
I have a S-38E Mark 2 and it has the rear mounted potentiometer.
I also just received the Haystack capacitor kit and will install these.
Ill FIRST change out the AC wiring to correctly wire the Neutral to the
chassis instead of the HOT/LINE on the chassis.
How did the Hallicrafter's engineers EVER decide to make the chassis HOT!
--
Glen Jenkins, WB4KTF, S-38E
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re “Hallicrafters re-design is often quite innovative, perhaps new engineers”?? ya? due to the UL imposing that or those captive sockets on the back cover Not only Halli had to change. ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Sunday, October 27, 2024 7:41 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Wanted: Schematic for S-38E? On some S-38 versions the chassis is hot, used as the B- return but
in all the cabinet is NOT hot. In earlier versions the chassis is
isolated from the cabinet by mounting it and switches, etc, on
insulators. In later versions, the B- return is wired separately from
the chassis, so neither chassis nor cabinet is hot. I have forgotten
where this change was made and am too lazy to look at the schematics. In
any case, Hallicrafters went to some trouble to eliminate shock hazard.
You can sometimes feel a slight sort of vibration on the surface of
the cabinet. This is due to the cabinet having a little AC on it through
the bypass caps used to connect the cabinet at RF in order for it to be
a shield. These are very small caps but do pass some 60Hz, enough to
produce a sensation when running your fingers over the surface. Not
dangerous. However, the cap or caps (usually two) should be checked for
condition. I believe they are ceramics.
If you connect the third wire to the chassis in sets that use the
chassis for B- you will short the supply, not a good idea.
One effect of the AC/DC supply is that reversing the line plug can
affect the residual hum. Should be connected for minimum hum, as noted
in the instruction book.
The versions with separate B- wiring are probably safer than the
others, I wonder if the wiring or the insulatatos of the earlier models
was more expensive to build. Hallicrafters re-design is often quite
innovative, perhaps new engineers.
On 10/27/2024 1:32 PM, Glen Jenkins WB4KTF wrote: Hello Don and others,
I have a S-38E Mark 2 and it has the rear mounted potentiometer.
I also just received the Haystack capacitor kit and will install these.
Ill FIRST change out the AC wiring to correctly wire the Neutral to the
chassis instead of the HOT/LINE on the chassis.
How did the Hallicrafter's engineers EVER decide to make the chassis HOT!
--
Glen Jenkins, WB4KTF, S-38E
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
-- don??? va3drl
|
Well, partly regulation but the manner of accomplishing it. Also,
not all changes in their products were due to regulations. Partly they
were fighting competition, some from established U.S. companies but also
from Japanese and other foreign makers.
Its interesting to look at the products just following WW-2,
Hallicrafters was making new receivers, or at least substantially
restyled receivers, National was still pushing the HRO, restyled but not
redesigned. Pretty soon folks like Drake came along. Also, the economy
went bananas, during the war there was heavy regulation of everything,
brakes came off after the war, tremendous inflation, labor troubles,
etc. Many assumptions that were made about the post-war market were
wrong. Worth some study.
toggle quoted message
Show quoted text
On 10/27/2024 5:39 PM, don Root wrote: Re “Hallicrafters re-design is often quite innovative, perhaps new
engineers”?? ya? due to the UL imposing that or those captive sockets on
the back cover Not only Halli had to change.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
I was specifically speaking of the power supply interface and safety. Around then, few house circuits were polarized, and I think they were first polarized only if they ?also had the ground pin[but there may have been some]. ??Unless I have crossed my wires, the sub topic? was? regarding taking one of the two power wires right to the chassis on a S-38[E version].? When it comes to RF stuff Halligan from his first Skyrider made changes on the fly it seems. ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Sunday, October 27, 2024 9:51 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Wanted: Schematic for S-38E? Well, partly regulation but the manner of accomplishing it. Also,
not all changes in their products were due to regulations. Partly they
were fighting competition, some from established U.S. companies but also
from Japanese and other foreign makers.
Its interesting to look at the products just following WW-2,
Hallicrafters was making new receivers, or at least substantially
restyled receivers, National was still pushing the HRO, restyled but not
redesigned. Pretty soon folks like Drake came along. Also, the economy
went bananas, during the war there was heavy regulation of everything,
brakes came off after the war, tremendous inflation, labor troubles,
etc. Many assumptions that were made about the post-war market were
wrong. Worth some study.
On 10/27/2024 5:39 PM, don Root wrote: Re “Hallicrafters re-design is often quite innovative, perhaps new
engineers”?? ya? due to the UL imposing that or those captive sockets on
the back cover Not only Halli had to change.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
-- don??? va3drl
|
Glen Jenkins WB4KTF
don Root