Re: Hallicrafters S40-B Restoration Advice
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.
?
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.
?
Picture shows receiver with one of my SW loop antennas.
?
Good Luck,
?
Bob C.
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Re: Hallicrafters S40-B Restoration Advice
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:
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
--
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
|
Re: Need help with HT-40 MK 1 troubleshooting
Joe,
Thanks for the info from the mods. Had a break through early this morning.
?
I kept staring at the function switch and something didn't look right, so I enlarged the photo of the function switch for the Mark 1, which is different than the standard HT40.
?
I thought this was a factory assembled unit, all the tube sockets and terminal strips are riveted with lock washers. But in it's 60 year life someone else was in there. The function switch had one wire about 3 terminals off in the wrong direction. At 2 am this morning I fixed that wire and all the voltages fell into place.? I went to sleep.
?
Just got back from days activites. I put a new 6CX8 and new 6DQ5 in the rig. Oddly it still shows no grid current in tune but when I went to AM or CW I have power out. On CW I get about 55 watts out and can modulate the rig and hear myself on AM. The Drive control does function to peak the output, just have to figure out why it's not showing on the meter.
?
Thank you for all your help.?
Larry
WA2DGD
?
PS:? found a ground missing on the meter switch, now I can read Grid Current. Now to get it on the air.
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Hallicrafters S40-B Restoration Advice
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
|
Re: Need help with HT-40 MK 1 troubleshooting
I found this info on the web.? It's from the document "HT-40 Preferred
Upgrades.pdf".? You can search for it.? I think it's for the plain HT40
and not the Mark 1.? (I've still been trying to figure out the function
switch without any luck.? Clean it and make sure it's switching properly.)
>>>>>The Buffer-Multiplier-Driver Stage
The Buffer-Multiplier-Driver stage V1B uses the same 6CX8/6HF8 as
described above except the pentode section is used as the Buffer-
Multiplier-Driver. It buffers the oscillator from the Final, multiplies
the frequency when necessary, and also drives the grid of the 6DQ5
Final. See Page 2 of the manual for the frequency multiplication process.
Without the buffering function of this stage, impedance changes at the
output of the transmitter would be reflected back to the oscillator,
changing the crystal's oscillation frequency and V1A's stage gain.
Some Turkey-Bird owner had replaced R4 with a 1 Megaohm resistor.
Undoubtedly this contributed to the demise of R5 since this stage was
operating in saturation rather than in class C. Furthermore, with the 1
Megaohm resistor value, I doubt any frequency multiplication could
occur. You know, if 100k is good, then 1 Megaohm has to be 10X better!
After the necessary component changes and power-on, there was no RF
output even though the filament was lit. I checked this original tube
once again in the tube checker and wolla, it was failing on all counts,
most likely due to the R4 component change and subsequent suffering.
So a NOS tube went in and power output was restored. Always measure the
cathode resistor R5 and the screen resistor R6. I found R5 was
715 ohms so it was replaced with a metal film resistor of the stated
value of 470 ohms. R6 was right on and miraculously, I have found this
12K resistor to be stable in most HT-40's. In this case, and due to the
failure of the original V1B, I replaced both R6 and L2.
Another Turkey-Bird moment was found when the expected stage gain wasn't
as high as it should be. If this was originally a Kit, then
Turkey-Bird forgot to solder in C11 from the cathode Pin 6 and to
ground. With C11 now in circuit the stage gain was higher, with less RF on
the Keybias rail.
This stage feeds the 6DQ5 Final's grid via a pi-net input circuit. RF
feedback from the Final is fed to the junction of C14 and C15 to curb
any parasitic oscillations and is a Neutralizing circuit. I have never
experienced any neutralization problems in an HT-40 with or without a
stub at the 2 lug terminal strip next to the Final.
The Cathode Bias Rail:
This transmitter uses cathode bias to shut off the
buffer-multiplier-driver and Final tubes on Keyup. In Keyup a high
voltage is on the V1B
and V2 plates but very little current is flowing through the tubes, but
it is enough current (0.7 mA) to pull the cathodes up to a voltage of
32V across R2. This voltage reverse biases the tubes and keeps them from
amplifying RF.? On Keydown, the “Keybias” voltage goes to zero allowing
the V1B and V2 tubes to conduct.
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On 4/4/2025 3:51 PM, AJ8MH Radio wrote: I wouldn't worry abut the secondary voltage.? However, I have bucking
transformers on my outlets to lower the commercial AC down from 120v.
Question...? You wouldn't happen to have something connected to pins 1
and 2 on TA1.? You should only have a short across pins 3 and 4.
V1 pin 6 and pin 3 (L1 and C8) voltages look close enough.? I don't
understand why...with such a high voltage on pins 9 and 8 of V1.
It looks to me like the junction of L1 and C8 gets its voltage thru
the HOT R7 back thru R3, thru the S3 front function wafer pins 1 and
2.? But, only in tune.? In CW, that voltage appears to come from R20
and R21 thru front function wafer pins 3 and 5. That's in the same
circuit as R29 and the neon lamps, which should be on in CW (I think)
and flicker in AM with modulation.? My eyes have gone double vision
trying to figure it out.
I wish someone else would tell us if their neon lamp is on during
CW...? Well, that's it from me.? Someone else needs to chime in.
On 4/4/2025 1:44 PM, Larry - WA2DGD via groups.io wrote:
Joe Hutchens
AJ8MH - Radio
Marquette, MI
--
Joe Hutchens
AJ8MH - Radio
Marquette, MI
|
Re: Need help with HT-40 MK 1 troubleshooting
TA1 Terminals 1&2 have nothing connected to them and 3&4 are shorted together.
?
I'll try and find a youtube video demonstrating the HT40 and see if the neon bulb lights on CW.
?
Next week if no one else chimes in I'll try getting in touch with Walt Cates for help.
?
Have a nice weekend and thanks again.
?
PS..checked youtube. The modulation lamp should be on in the CW position.
?
Larry
WA2DGD
|
Ahh Jim ?, yes I guess it means that too many.? I use pre-octal [it doesn’t sound so demonstrative], but I am trying to confirm that I was really sending what the AI experts know. Do you agree with them? ? Back to the 5-T, I would agree, about the tubes suggesting that it was designed perhaps before about ?may, june, july 1935 ?when the new octal tube data became known the first ad I saw for the 5-T?? was in: ?? ?somewhere,??? BUT a bigger one was in: ??? ?? pdf page 8??? ? ?still?? Marion???? Indiana I just wonder they used all the new octal/metal sockets and tubes for the ?flagship Super sky-riders and left the older stuff for the sky buddy. That might make good business sense. I worked in an industrial electronic plant for a while, so I wonder who bends and punches the steel chassis, front panel, and cabinet ? were machines easily available to do some bends?? Maybe it depends on just what is available? maybe they contract out the steel, maybe not The month after this last ad, they changed the address to 2611 indiana so the first 5-Ts might be made at either place ? Wandering back to the early skyriders, and where they were actually made; nobody seems to have evidence of what happened to the SMI license from RCA when the they split up in Oct 1932. ??? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Wednesday, April 2, 2025 6:00 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] New to Group? By "big pin" I was referring to tubes that were common before the arrival of the octal tube around 1935.? The hallicrafters 5T uses all pre-octal tubes found in the RC-11 RCA tube manual (circa 1933) so it's design was completed before the octal tube was available to the radio designer.? The 5T must have been on the drawing board of a company bought by hallicrafters or it was the pet project of an early hallicrafters employee. Sorry for the confusion and the use of the term, I assumed that everyone was familiar with this?idiom. ? -- don??? va3drl
|
Richard,? loctal /? loktal? ..s were spoken about ?in this? 1938-12 article: ? pdf??? 20?? -----  ??
but ?March 1939 revealed some data ? pdf?? 59??? ----- From some reading it seems that RCA? and philco? were in a battle so philco started a deal with Sylvania ??much earlier maybe ?? Probably, the RF tubes for TV is what drove the loktal design ahead of octals due to lower ?capacitance ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow via groups.io
Sent: Wednesday, April 2, 2025 6:20 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] New to Group? Turns out that octal base tubes were introduced by General Electric
when they introduced metal tubes, 1935. My memory was incorrect about
Locktal base, it was introduced by Sylvania. Don't have a date but mid
to late 1930s.
-- don??? va3drl
|
Are the SR-160/SR-500/SR-150 control knobs the same size as the HT-44/SX-117 knobs?
Thanks. 73, Scott WA9WFA
|
Re: Need help with HT-40 MK 1 troubleshooting
I wouldn't worry abut the secondary voltage.? However, I have bucking
transformers on my outlets to lower the commercial AC down from 120v.
Question...? You wouldn't happen to have something connected to pins 1
and 2 on TA1.? You should only have a short across pins 3 and 4.
V1 pin 6 and pin 3 (L1 and C8) voltages look close enough.? I don't
understand why...with such a high voltage on pins 9 and 8 of V1.
It looks to me like the junction of L1 and C8 gets its voltage thru the
HOT R7 back thru R3, thru the S3 front function wafer pins 1 and 2.?
But, only in tune.? In CW, that voltage appears to come from R20 and R21
thru front function wafer pins 3 and 5. That's in the same circuit as
R29 and the neon lamps, which should be on in CW (I think) and flicker
in AM with modulation.? My eyes have gone double vision trying to figure
it out.
I wish someone else would tell us if their neon lamp is on during CW...?
Well, that's it from me.? Someone else needs to chime in.
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On 4/4/2025 1:44 PM, Larry - WA2DGD via groups.io wrote:
Joe Hutchens
AJ8MH - Radio
Marquette, MI
|
Re: Need help with HT-40 MK 1 troubleshooting
I tend to agree with your feeling that the voltages are high because no current is being drawn.
?
Here are the measurements you requested. These were done with the original 6CX8 and 6DE7. I also repeated the measurements with?
2 new 6CX8's and 2 new 6DE7...all measurements were within 1 volt of each other. I checked all the grounds on V1 and did notice that C7, a .01?
had the ground attached but not soldered, I resoldered it...no joy.
?
V1 Pin 6? Keyed = 14 vdc,? Unkeyed = 40 vdc
V1 Pin 3 at L1-C8 junction? Keyed = 107 vdc,? Unkeyed = 125 vdc?
?
As I said both neons flash turning function switch but front panel neon does not light during cw.
?
I also noticed the 6DE7 acts a series regulator..replaced it also...no change.
?
Another voltage that is way off is V1 Pin 8 should be around 210 vdc, I have full B+ at Pin 8 >585 vdc.?
R3 measures 22k and R7 measures 2500 ohms but gets very hot. Also the seondary of the transformer should be around 195 vac, I have 225 vac. My line voltage is usually around 123 vac.
?
I appreciate your help, this is almost driving me to go back to work...it was easier.
?
Thanks,
Larry
|
Re: Need help with HT-40 MK 1 troubleshooting
No lamp in tune or AM.? Only CW.? Just checked.
On 4/4/2025 11:57 AM, Joe Hutchens
wrote:
I still feel like V1 isn't doing much.? Have you tried a new 6CX8?
Have
you checked the heater voltage?? How about any tube socket grounds
to
the chassis?? If all the voltages are high, current isn't being
pulled
from the power supply...I think.? What is pin 6 at keyed and
un-keyed??
What about the V1 pin 3...200 v? I would measure that at L1 and
C8. I
believe both neon lamps are lit in AM or CW.? Maybe, in tune
also.? I
haven't check my transmitter.? The 6DE7 acts as a series regulator
when
in CW.
On 4/3/2025 7:09 PM, Larry - WA2DGD via groups.io wrote:
Joe Hutchens
AJ8MH - Radio
Marquette, MI
--
Joe Hutchens
AJ8MH - Radio
Marquette, MI
|
Re: Need help with HT-40 MK 1 troubleshooting
I still feel like V1 isn't doing much.? Have you tried a new 6CX8? Have
you checked the heater voltage?? How about any tube socket grounds to
the chassis?? If all the voltages are high, current isn't being pulled
from the power supply...I think.? What is pin 6 at keyed and un-keyed??
What about the V1 pin 3...200 v? I would measure that at L1 and C8. I
believe both neon lamps are lit in AM or CW.? Maybe, in tune also.? I
haven't check my transmitter.? The 6DE7 acts as a series regulator when
in CW.
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On 4/3/2025 7:09 PM, Larry - WA2DGD via groups.io wrote:
Joe Hutchens
AJ8MH - Radio
Marquette, MI
|
Re: Need help with HT-40 MK 1 troubleshooting
The -50 vdc on the grid is the effect?of grid leak bias. It is developed across R9 and R10. It will only reach -50vdc with proper drive and normal power output.
Walt Cates, WD0GOF
?
A majority of acceptance is not proof of correctness.
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Hi Joe,?
?
Thanks for the reply.
?
I left a few things out in my first post.?
?
As you suggest, I have RF at V1, same as the crystal frequency, 7.125. I can trace the rf signal all the way from the oscillator, to the buffer, thru the bandswitch and to the grid of V2 pins 1,5. I can see the 7.125 signal at the output of V2 and the
SO239 connector. The biggest issue the grid drive, looks like V2 pin 1,5 should be -50vdc and I only have -5.00vdc. I'm not sure where the -50vdc originates.
?
The power supply is giving me over 585 vdc on a VTVM in AM and the same in CW, the schematic shows 430 vdc CW and 500 VDC AM. I'm not sure these are off due to the problems with the Grid Drive. The 210 vdc at V1 pin 8 is much higher, almost at supply voltage,
575vdc and the 12k measures good. Also pin 9 is at same voltage as pin 8. ?
?
As suggested in a previous post, I can trace the -5vdc Grid from V2 back thru the switched inductors and bandswitch, but I can't find -50vdc anywhere.
Both neon lamps are working, the original under chassis one was blown and I replaced it, I can see both flash when I turn the rig on or off.
?
I thought possibly C19 shorted and was pulling down the voltage, I disconnected it, voltage rose to -15vdc but it tested at 9pf on my capacitance meter. I replaced it.
?
Thanks for the help. If you think of anything else, please let me know.
?
Regards,
Larry
|
Re: Need help with HT-40 MK 1 troubleshooting
Hi Joe,?
?
Thanks for the reply.
?
I left a few things out in my first post.?
?
As you suggest, I have RF at V1, same as the crystal frequency, 7.125. I can trace the rf signal all the way from the oscillator, to the buffer, thru the bandswitch and to the grid of V2 pins 1,5. I can see the 7.125 signal at the output of V2 and the SO239 connector. The biggest issue the grid drive, looks like V2 pin 1,5 should be -50vdc and I only have -5.00vdc. I'm not sure where the -50vdc originates.
?
The power supply is giving me over 585 vdc on a VTVM in AM and the same in CW, the schematic shows 430 vdc CW and 500 VDC AM. I'm not sure these are off due to the problems with the Grid Drive. The 210 vdc at V1 pin 8 is much higher, almost at supply voltage, 575vdc and the 12k measures good. Also pin 9 is at same voltage as pin 8. ?
?
As suggested in a previous post, I can trace the -5vdc Grid from V2 back thru the switched inductors and bandswitch, but I can't find -50vdc anywhere.
Both neon lamps are working, the original under chassis one was blown and I replaced it, I can see both flash when I turn the rig on or off.
?
I thought possibly C19 shorted and was pulling down the voltage, I disconnected it, voltage rose to -15vdc but it tested at 9pf on my capacitance meter. I replaced it.
?
Thanks for the help. If you think of anything else, please let me know.
?
Regards,
Larry
|
Re: Need help with HT-40 MK 1 troubleshooting
Sounds like you don't have any RF at V1.? I'm assuming you're using xtal
control.? S1 should be in XTAL.? I have a jumper across? TA1 3 and 4 and
a key plugged into the key jack.? You should be able to hear the crystal
on a nearby receiver when in tune without keying the radio. See what
happens at V1 pin 6 when you key the transmitter in tune.
My schematic shows 2.5 mh for L1 and 190 volts thru to the plate V1 pin
3.? L2 100 uh and 350 volts thru to the plate V1 pin 9. It's 210 volts
on pin 8 thru R6 (12K 2watt).
Make sure the two neon lamps are working. One is under the chassis.? The
other is the right lamp on front panel.? Hope it's not a wafer switch issue.
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On 4/3/2025 12:56 PM, Larry - WA2DGD via groups.io wrote:
Joe Hutchens
AJ8MH - Radio
Marquette, MI
|
Re: Need help with HT-40 MK 1 troubleshooting
Since you state you cannot get any grid drive probably is the root of your problem.? Troubleshoot backwards and find out where you lose the grid drive. k6lr
|
Need help with HT-40 MK 1 troubleshooting
Hi all,
New member here and recently retired, have been a ham since 1967 and started to fix/refurb old ham radio equipment in my leisure time now.
So far successful with some old receivers..Knight Kit Star Roamer, Heathkit 303 and most recently a Hammarlund HQ-100A.
?
So now I decided to try a transmitter to go along with the HQ-100A and picked up a beautiful Hallicrafters HT-40 Mark 1 in great physical condition but known problem.....only can get 2 watts out. I thought this would be a great project but now I'm not so sure. I think I'm reaching the point where I could use some help.
?
I've attached the schematic I've been working from that closely matches my rig. When I received it I brought it up slowly on a variac and sure enough.,.Only 2 watts out.
I figured I'd do the basics since it appears all original...I replaced all electrolytics and any HV paper caps,? also replaced any resistors or caps that were more than 10% off, (except all disc ceramics) and cleaned all switch contacts.
Fired it up again...only 2 watts out.
?
Long story short... I replaced each tube individually and then tried all new tubes..... still 2 watts out.
The biggest issues are.
1) cannot get any grid drive in tune position
2) I have only -5 vdc to +1.0 vdc on the Grid of the final V2 depending on position of Drive cap instead of -50vdc according to schematic.
3) Again, the Final V2 Pin 4 and 8 should have 130vdc in CW and 30vdc in AM. I have 26vdc in CW and 12 vdc in AM??
4) Tube V1 Pin 8 should have 210vdc but I'm getting 350vdc and I've replaced R3, R6 and R7.
?
I've resoldered almost all connections, wiggled each tube socket terminal during transmit...nothing changes.
The only thing I found different was L2 is a 5uh choke instead of 100uh, don't know if this was a modification or mistake. I put a 100 uh in its place....still 2 watts out.
I'm really stuck at this point and tested most components except the .001 and .005 ceramic disc caps, any of those I did pull and tested were good.
?
I'm hoping someone could lead me in the proper direction.
Thanks,
Larry
WA2DGD
|
Turns out that octal base tubes were introduced by General Electric
when they introduced metal tubes, 1935. My memory was incorrect about
Locktal base, it was introduced by Sylvania. Don't have a date but mid
to late 1930s.
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On 4/2/2025 2:31 PM, Richard Knoppow via groups.io wrote: I always understood "big pin" tubes to be those made before octal
sockets were introduced. Many octal tubes are essentially the same as
earlier "big pin" tubes except for the sockets and dimensions of the
glass envelopes.
Big pin tubes could have four or more pins, as many as six (maybe
more) and often top caps for grids or plate. The pins of big pin tubes
were not all the same, usually two were larger to "key" the tubes so
they would fit in only one way.
I don't know the date when octal tubes were introduced, sometime
around the mid 1930's I think. It seems to me that metal tubes were
introduced not long afterward. A little later came "locktal" tubes,
introduced by Zenith (again by memory and could be wrong). These were
similar to octal base except had locking pins and a metal base. Many
similar types were made with both bases (and different numbers). Loktal
base tubes were popular for automobile radios where they tended to be
more firmly connected.
On 4/2/2025 2:20 PM, don Root wrote:
Hi Jim, I have been trying to reply but keep getting diverted.
One problem is understanding the definition of a “big pin” tube. How
big
is “big”? ?I can find no definition. the 4,6,and older 7
Ing tubes have two ?0.156 ?[5/32?] inch pins and some .125 [1/8]inch
pins but the 5 pin tube has only the smaller pins.
Anyhow, I googled with “what is? a "big pin" radio tube?” and AI
replied
as follows”
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Don By "big pin" I was referring to tubes that were common before the arrival of the octal tube around 1935.? The hallicrafters 5T uses all pre-octal tubes found in the RC-11 RCA tube manual (circa 1933) so it's design was completed before the octal tube was available to the radio designer.? The 5T must have been on the drawing board of a company bought by hallicrafters or it was the pet project of an early hallicrafters employee.
Sorry for the confusion and the use of the term, I assumed that everyone was familiar with this?idiom. Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
Hi Jim, I have been trying to reply but keep getting diverted. One problem is understanding the definition of a “big pin” tube. How big is “big”? ?I can find no definition. the 4,6,and older 7 Ing tubes have two ?0.156 ?[5/32?] inch pins and some .125 [1/8]inch pins but the 5 pin tube has only the smaller pins. ? Anyhow, I googled with “what is? a "big pin" radio tube?” ????and AI replied as follows” AI Overview A "big pin" radio tube, also known as a vacuum tube or electron tube, is a type of electronic device that uses the flow of electrons in a vacuum to control electrical signals, often used in older radio and audio equipment.? Here's a more detailed explanation: A "big pin" radio tube is a type of vacuum tube, a device that uses the flow of electrons in a vacuum to control electrical signals.? ·? ·? How it works: Inside the tube, a heated filament (cathode) emits electrons, which are then controlled by a grid (a metal mesh) and attracted to a positively charged plate (anode).? ·? ·? Why it's called "big pin": The term "big pin" likely refers to the size and shape of the base or connector pins on the tube, which are larger than those on smaller tube types.? ·? ·? Examples: Some common "big pin" tube types include the 6L6, 6V6, 6K5, and 6C5.? ·? ·? Historical Context: Before the advent of semiconductor devices, vacuum tubes like these were widely used in various electronic applications, including radios, audio amplifiers, and television sets.? ·? ·? Modern Usage: While largely replaced by transistors and other solid-state devices, vacuum tubes are still used in some applications, particularly in audio amplifiers and specialized electronic equipment where their unique sound characteristics are desired.? ? More stuff later. ?
From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Sunday, March 23, 2025 11:49 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] New to Group ? AFAIK, all of the hallicrafters listed below have metal front panels and are housed in metal cases.? The S-10 / SX-10 did have an optional mahogany?case that the metal case slipped into but I doubt that any were actually sold.? If the production numbers are correct, at one time I owned 1.5% of production!? That would be three of them out of some 200 reportedly made. Still have two. The 5T is an odd one.? It uses all big pin tubes so it is obviously a much earlier design.? It is either the first or fourth superhetrodyne design sold by hallicrafters. hallicrafters receiver models Information gleaned from Max de Henseler and Chuck Dachis books S-1, S-2, S-3 TRF-regen, 5 tubes, manufactured by Silver-Marshall?, 1934 ++++++++++++++++++++++
--
don??? va3drl
|
Dexter
Anthony W. DePrato
Richard AG5M
don Root
waltcates
Jim Whartenby