Hallicrafters S40-B Restoration Advice
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Hello all, this being my first post here.? I recently acquired a Hallicrafters S40-B receiver from a dear friend who went SK.? I had promised to restore it for him, so even though he is gone, I'll keep my promise.? From the looks of it it's all original with no one ever having been inside it, unused for unknown amount of time.? Manufactured Nov. 17, 1952.? Even had the original manual in it.? So what you see is 1952 dirt and a lot of old paper caps, etc.? I'm an old timer, licensed in 1963, so tube rigs are not new to me.? I have not plugged it in yet, and yes, I know all about Dim-Bulb-Testers, Variacs, etc.? I have analog and digital meters, AF and RF generators, O'Scope, tube testers, etc.? Just looking for some up front advice from anyone who has been down this path before with this or similar Hallicrafters receivers, what to watch out for, anything special to think about?? Thank you, 73, Richard AG5M |
开云体育i have restored an S40 S40A and a S40B. all are EZ restores.
first thing to do is replace all the Caps. then check for out of
range resistors last thing is check the tubes. good luck the S40B is a great receiver . 73 Tony WA4JQS On 4/6/2025 6:04 PM, Richard AG5M via
groups.io wrote:
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Anthony W.DePrato WA4JQS CQ DX HALL OF FAME #39 DXCC HONOR ROLL CW PHONE RTTY CALLS HELD VP8SSI VP8BZL V31SS 3Y0PI ZS8JQS WA4JQS/KC4 WA4JQS/ZS1 |
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Been there; done that about 10 years ago.? I got the recap kit from Hayseed Hamfest.? Link: ?.? Also replaced toggle switches for which I was able to find OEM parts.? Had to find a replacement main tuning dial, as original was warped.? At the time, they were available on eBay.? Also, new line cord, etc.
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Mine had been wired for a Heathkit Q-multiplier.? I happened to have one, so I just plugged it in and tweaked the IFs.? Adds necessary selectivity if you intend to do some serious listening.
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Picture shows receiver with one of my SW loop antennas.
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Good Luck,
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Bob C. |
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Hello Richard!
I've just done an S85.. very similar rig. Just search the group...for more info.
Here are some of choices I made.
Be aware of C56. It is an hazard to your life! It's also called the "death capacitor".
I replaced it with a modern CM main filter pulled from on old printer:
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I didn't want to mess with desoldering the original components to avoid stressing the original terminal too much.
In particular the IF cans terminals are internally bonded with very heat sensitive plastic frame that melts very easily (not sure for the S40).
I used the "spring terminal" approach with very satisfactory result:
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About the two 6.3V-0.3A filament bulbs: I had to replace both, but had to buy 100!! So I have 98 left for selling.
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Emanuele (IU1KNR). |
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Hi Dexter, Can you send a close-up photo(s) of your loop antenna?? Is it tunable? 73. Joe? AB1YO
On Monday, April 7, 2025 at 10:28:59 AM EDT, Emanuele Girlando via groups.io <emanuele_girlando@...> wrote:
Hello Richard!
I've just done an S85.. very similar rig. Just search the group...for more info.
Here are some of choices I made.
Be aware of C56. It is an hazard to your life! It's also called the "death capacitor".
I replaced it with a modern CM main filter pulled from on old printer:
?
I didn't want to mess with desoldering the original components to avoid stressing the original terminal too much.
In particular the IF cans terminals are internally bonded with very heat sensitive plastic frame that melts very easily (not sure for the S40).
I used the "spring terminal" approach with very satisfactory result:
?
?
About the two 6.3V-0.3A filament bulbs: I had to replace both, but had to buy 100!! So I have 98 left for selling.
--
Emanuele (IU1KNR).
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Joe, complete plans for a similar model loop antenna covering approximately 2.6 to 12.3 MHz is pictured below and described at
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The model shown previously with the S-40B covers 3.4 to 15 MHz.? Each is essentially a transformer.? The primary is an LC resonant circuit.? The secondary is coaxial in the center and provides low-impedance output to a twisted pair, which is connected to the receiver.? The secondary size is switch-selectable to provide best impedance match across the tunable spectrum.
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I have several models using the same principles which cover 150 kHz through 23 MHz.? A detailed theory, construction and operation of a medium-wave loop is at
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For optimum peaks and nulls, the loop should really be adjustable 90-degrees vertically in addition to 360 degrees horizontally (the one pictured is not).? For complete rotation and elevation I have a wooden tripod, and each antenna assembly is mechanically balanced and fitted with a universal, fork.? At shortwave frequencies, signal nulls are problematic, but the loops are exceptional for cancelling local noise.
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Further questions?
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Bob C.
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Thank you Bob, 73. Joe? AB1YO
On Monday, April 7, 2025 at 05:11:11 PM EDT, Dexter via groups.io <dexterdxer@...> wrote:
Joe, complete plans for a similar model loop antenna covering approximately 2.6 to 12.3 MHz is pictured below and described at
?
The model shown previously with the S-40B covers 3.4 to 15 MHz.? Each is essentially a transformer.? The primary is an LC resonant circuit.? The secondary is coaxial in the center and provides low-impedance output to a twisted pair, which is connected to the receiver.? The secondary size is switch-selectable to provide best impedance match across the tunable spectrum.
?
I have several models using the same principles which cover 150 kHz through 23 MHz.? A detailed theory, construction and operation of a medium-wave loop is at
?
For optimum peaks and nulls, the loop should really be adjustable 90-degrees vertically in addition to 360 degrees horizontally (the one pictured is not).? For complete rotation and elevation I have a wooden tripod, and each antenna assembly is mechanically balanced and fitted with a universal, fork.? At shortwave frequencies, signal nulls are problematic, but the loops are exceptional for cancelling local noise.
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Further questions?
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Bob C.
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Bob Thank you for that tip, I might have missed it, now I won't. Gathering parts right now, beginning to clean it up, lots of dirt, but no corrosion, thank to it having lived its life in a dry climate. No humidity where here in the EWA desert where I live. 73, Richard AG5M On Monday, April 7, 2025 at 08:03:34 PM PDT, Robert Eckweiler <af6c@...> wrote: When you get around to alignment, remember that the heterodyne oscillator tracks above the received frequency by 455 Kc on all band EXCEPT the top band (15.5 to 44 Mc). There it tracks below the received frequency. ?I don't think that was made clear in the manual. ? On the S-40B receiver I recently worked on, the person who last aligned it didn't know this, and the slug was half out of the top of the coil and that band just wouldn't track.? ? Bob, AF6C ? |
Richard AG5M
Anthony W. DePrato
Dexter
Emanuele Girlando