Re: SR-160 Vernier Dial Lubricaion
Hi Walt,
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I have cleaned the old grease and added a small amount of white grease to the gears.? That has helped quite a bit.? However, the dial still sticks a bit.??
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I also cleaned up the clutch plates.? Should I lube the clutch plates or leave them dry?
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Re: SX-62B alignment instructions
Scott, re? ?V8, I see it is called an FM limiter and AM detector, which is confusing; and now I see that the Plate and Screen voltage is switched by S1-BB? way over …so I believe V8 is switched to function between a FM limiter or an AM detector. The screen and plate voltage are both reduced [some books say 30 volts typical] for operation as a limiter. Perhaps you can measure that that band 5,6 FM ?reduces
? If not, it might have too much gain .? just a thought ? I started looking at the manual and saw that it has a Multiplex out phono jack. You might want to look/listen to the FM audio from there, which is before the switches, then you should know if the problem is in the limiter /discriminator or Not. Likely so, but better to narrow down with confidence. Seems to me, a sweep gen and scope might be needed,? but the usual? look and probe might reveal something ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Scott Petersen via groups.io
Sent: Monday, March 17, 2025 6:49 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] SX-62B alignment instructions? It looks like the area I'm having trouble with, I will study it for a while, I also have trouble with following the signal path. Thanks! going to spend some more time on it tomorrow., We just had corned beef and cabbage, overstuffed... -- don??? va3drl
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Re: SX-122 Calibration Questions
Thanks, Jim. ?Yes, it’s a bear to turn over. ?I don’t have full mobility in my left arm which makes it even more exciting. ?Yes, I’m receiving stations on all ham bands thanks in large part to excellent solar conditions.
Peaking the 50Khz in accordance with the manual. ?V3, a 6C4 removed to isolate the IF stages from the RF amp. ?Then signal form a TinySA ?input at Test Point B, measured with DMM at the designated point and the 50Khz If transformers peaked. ?Worked like a cham and no issues.
The test setup for the manual calls for the audio gain to be set at maximum for all the IF and RF adjustments so the technique of using ears and the speaker won’t work. ?Not that you can’t hear it but it’s at rock concert level. ?The book calls for a 3.2 ohn resistor across the speaker and the use a VTVM across the resistor to make the adjustments. ?No problem with that. ?I have a 4 ohm dummy load that I used when working on guitar amp that did the job quite well.
I’m scratching my head over the 1650Khz IF but will try it again after thinking about it for a while. ?It can’t be far off, if at all, because the set is working so well. ?
So I’m going to finish the RF alignment, skipping the slugs for the moment, hook up the antenna and see how much better it hears. ?Expect quite a difference since I’ve already seen big increases in output from 50Khz alignment and the partial RF tweaking even temporarily ignoring the slugs. ?
Obviously I’ll have to do at least the RF section again when I find the key to the slugs.
Hope that answered your questions and thanks again for your input.?
John - K8NN
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Re: SX-122 Calibration Questions
Thanks, Jim. ?I could have been clearer. ?The wax is not blocking access to the slugs so won’t need to melt it. ?I can see the top of the slugs but difficult to get enough light in there while seeing past it and determining what style alignment tool is required. ?Being extra cautious in case they’re brittle. ?
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Re: SX-62B alignment instructions
I would certainly invite you over if we were within driving distance!
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Scott
Please sir I hungry too ???well I guess it is actually ?“Please, sir, I want some more.”
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don??? va3drl
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Re: SX-122 Calibration Questions
John, can't help much with the alignment, but on other Halli's I have worked on, found that a hair dryer is a good bet on slugs that have wax above them... Simply invert the chassis (easier said than done), and melt the wax. Might be easier to leave chassis upright and blow the melted wax out.? Either way, you now have unrestricted access to the slugs...
Jim, k6lr
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Re: SX-62B alignment instructions
Scott Please sir I hungry too ???well I guess it is actually ?“Please, sir, I want some more.” -- don??? va3drl
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Re: SX-62B alignment instructions
Hi Don,
It looks like the area I'm having trouble with, I will study it for a while, I also have trouble with following the signal path. Thanks!
going to spend some more time on it tomorrow., We just had corned beef and cabbage, overstuffed...
Scott
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Scott, here is where I got to after slowly recalling some of the SX-42 ccts.
Is this AM/FM split? the way you and anyone sees it?? this stuff is tough to digest.
From the SX-62B on BAMA…….
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I have not recapped inside the Discriminator, or the IF's yet, maybe I have to do that, hoping I didn't need to, this unit seems to be the latest version, as the caps are the
plastic molded ones(replaced), unlike the SX-42, which were paper/ wax. The band switch looks like a later style also, as the shaft comes apart.
Hi Scott.? That’s good info. So the problem seems to be in the FM limiter /discriminator area ??I will do some head scratching, but others might have the answer first.
We had a day or two of nice weather, and I was out cleaning up flower beds so now I cant move.
?
?
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don??? va3drl
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don??? va3drl
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Re: SX-122 Calibration Questions
John, good to hear about your find. I am just trying to understand your situation, but I am a poor reader SO.. The 50kC? thru to the speaker works well ? The 1650 thru to speaker is not good .. weak output or noise, but works ?so something is not right in the 1650 despite attempting alignment? RE “But, as I said, the set is working” ?????means stations received ? What all do you have to test with?
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From: [email protected] [mailto:[email protected]] On Behalf Of John Limbach, K8NN
Sent: Monday, March 17, 2025 4:54 PM
To: [email protected]
Subject: [HallicraftersRadios] SX-122 Calibration Questions? Recently purchased an SX-122 in great condition.? ?Less cosmetic wear than you'd expect from an early '60s radio.? No mods or changes underneath and very clean there as well.? A few tubes had been changed but several still had the Hallicrafters markings.? Five of the tubes tested below acceptable level on my calibrated Hickok 539, so replaced them with NOS tubes that tested to spec.? The set performed well on my very short length wire that starts on the workbench in the basement and makes it's way up to the roof on the deck. -- don??? va3drl
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SX-122 Calibration Questions
Recently purchased an SX-122 in great condition.? ?Less cosmetic wear than you'd expect from an early '60s radio.? No mods or changes underneath and very clean there as well.? A few tubes had been changed but several still had the Hallicrafters markings.? Five of the tubes tested below acceptable level on my calibrated Hickok 539, so replaced them with NOS tubes that tested to spec.? The set performed well on my very short length wire that starts on the workbench in the basement and makes it's way up to the roof on the deck.
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With that done, I replaced the two discrete electrolytics, which showed increases in both capacitance and leakage. and ordered a replacement can cap.? Although the set is playing without any power supply hum, I change all 50+ year old electrolytics on general principles.? I located the five paper caps and found them to be high quality, not waxies, and looking as if they just came out of the box.? All five tested on my LCR meter to their nominal capacitance and the leakage was very small and virtually the same as the ones I would have replaced them with.? So, left them in.
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While waiting for the can cap, I decided to give it a preliminary alignment to see how far out it might be.? Tuning up the 50Khz made a big difference.? Had an issue getting an output on the 1,650Hhz IF.? Triple checked my setup, non-inductive 4 ohm dummy load on the audio output with the VTVM measuring across that, and still not seeing what I expected on the VTVM.? Even weirder with the speaker connected.? But, as I said, the set is working the second IF must be too.? Put that on the back burner waiting on some expert guidance and went ahead to the RF alignment.
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Starting with 30 & 14Mhz.? Pretty straightforward and was doing fine.? Got significant improvements at 30Mhz and was feeling good until I got to 14Mhz.? L12, L8, and L4.? Well L12 was no problem as it's threaded section comes an inch or two out of the top of the coil and uses a straight blade screwdriver adjustment (I use on ceramic screwdrivers wherever possible).? Man, that thing twitchy but finally conquered it and got significant improvement.? However things ground to a screeching halt with I hit L8, and L4.? The slugs are recessed and the opening on top has a lot of wax on it.? Doesn't block the hole, but it's darn hard to see down in there and figure out what shape tool is required.? I'm being very cautious about not damaging a slug.? One that I can see reasonably well apprears to have a wide, shallow, common screwdriver slot.? Wasn't able to get anything in that felt like it seated and no changes in output.
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So, to wrap up, I'd appreciate any thoughts on the 1,650 Khz alignment.? And also some guidance on what's needed to turn the slugs on all the recessed slugs.
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Thanks,
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John - K8NN?
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Re: SX-62B alignment instructions
Scott, here is where I got to after slowly recalling some of the SX-42 ccts. Is this AM/FM split? the way you and anyone sees it?? this stuff is tough to digest. From the SX-62B on BAMA…….
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From: [email protected] [mailto:[email protected]] On Behalf Of Scott Petersen via groups.io
Sent: Monday, March 17, 2025 1:41 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] SX-62B alignment instructions? I have not recapped inside the Discriminator, or the IF's yet, maybe I have to do that, hoping I didn't need to, this unit seems to be the latest version, as the caps are the plastic molded ones(replaced), unlike the SX-42, which were paper/ wax. The band switch looks like a later style also, as the shaft comes apart.
Hi Scott.? That’s good info. So the problem seems to be in the FM limiter /discriminator area ??I will do some head scratching, but others might have the answer first. We had a day or two of nice weather, and I was out cleaning up flower beds so now I cant move. ? ?
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don??? va3drl
-- don??? va3drl
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All…?? I have? SN 118296, it must be much older??? Is the run number on the inside or outside of the chassis?? Does the first run have a printed “run 1” and do run nums restart with mark 1 and mark 2 ? ??? -- don??? va3drl
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Re: SX-62B alignment instructions
I have not recapped inside the Discriminator, or the IF's yet, maybe I have to do that, hoping I didn't need to, this unit seems to be the latest version, as the caps are the plastic molded ones(replaced), unlike the SX-42, which were paper/ wax. The band switch
looks like a later style also, as the shaft comes apart.
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Hi Scott.? That’s good info. So the problem seems to be in the FM limiter /discriminator area ??I will do some head scratching, but others might have the answer first.
We had a day or two of nice weather, and I was out cleaning up flower beds so now I cant move.
?
?
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don??? va3drl
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Re: SX-62B alignment instructions
Hi Scott.? That’s good info. So the problem seems to be in the FM limiter /discriminator area ??I will do some head scratching, but others might have the answer first. We had a day or two of nice weather, and I was out cleaning up flower beds so now I cant move. ? -- don??? va3drl
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Re: SX-62B alignment instructions
Hi Don,
After I do the AM alignment part of the 2 high bands 88-108 and 27-55, I switch to FM, and there is no sound, because the RF gain control is all the way up,
as I lower the RF gain it begins to howl out of the speaker, then it finally drops into the normal audio hush. My o-scope is in storage, but I am using a frequency counter, and an RCA WR-50b signal generator. The generator output attenuator seems fine, and
cuts off the output on it's lowest setting.
The RF control works the same way with or without the generator running, and sounds terrible on a FM station, overdriven sounding, even with the RF control at its "best sounding position" between 2-3.using the settings as in the alignment setup. On AM the high
bands work, but not well on FM stations. The RF gain control can be advanced to 10 on the 2 top bands in the AM position, and pick up AM signals ok.
When I received the receiver all bands worked, but poorly, I don't remember if FM was proper before the recap, but it barely worked.
The general condition of the receiver is great, with all of the original tubes, which test as new. CW does work, but is turned off. The callibrator works, but is also turned off.
Thanks,
Scott
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Scott, I’m not too smart and also can’t read between the lines and words.?
What is oscillating?, and at what frequency? I guess you see it on a scope unless it is from the BFO and out the speaker.??
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You mentioned nothing about the history and if you have ever had it receiving or not on any band. ?
Will it work on AM/CW on all bands ? ?and it is just the FM detector?
On FM what happens with the signal generator off and an antenna ..nothing?, stations? Oscillations most of the time?
Is your RG gain pot in good shape, or is it noisy, erratic? ???
I have a sx-62 of some version in sick bay so I am extra curious but it will take a while to understand things.
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I did both alignments, and all seemed well until I switched in FM, and the gain was too high, and it wouldn't receive until I turned the RF control to 2-3, and only "works" in a small range,
either too high, and oscillates and blanks, or too low a gain to hear anything.
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don??? va3drl
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Re: SR-160 Vernier Dial Lubricaion
Hi Walt,
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Excellent advice! ?Thank you very much for your help!
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Re: SX-62 alignment instructions
Scott, I’m not too smart and also can’t read between the lines and words.? What is oscillating?, and at what frequency? I guess you see it on a scope unless it is from the BFO and out the speaker.?? ? You mentioned nothing about the history and if you have ever had it receiving or not on any band. ? Will it work on AM/CW on all bands ? ?and it is just the FM detector? On FM what happens with the signal generator off and an antenna ..nothing?, stations? Oscillations most of the time? Is your RG gain pot in good shape, or is it noisy, erratic? ??? I have a sx-62 of some version in sick bay so I am extra curious but it will take a while to understand things. ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Scott Petersen via groups.io
Sent: Sunday, March 16, 2025 9:26 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] SX-62 alignment instructions? I did both alignments, and all seemed well until I switched in FM, and the gain was too high, and it wouldn't receive until I turned the RF control to 2-3, and only "works" in a small range, either too high, and oscillates and blanks, or too low a gain to hear anything. -- don??? va3drl
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Re: SX-62 alignment instructions
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Don
Your IF alignment instructions are missing an important caveat.? You must lower the SG output to below where the AVC begins to operate.? Not doing so will cause the IFTs to be misaligned.? With the volume and RF gain controls at maximum, the
SG modulation should be heard but just barely over the background noise as the IF alignment progresses.??
Better to measure the voltage at the speaker terminals and not rely too much on one's hearing, especially as we get older, right Richard?.? This IF alignment method would be useable for all superhetrodyne receivers, not just hallicrafters.
Might as well mention that if the radio has a crystal filter in the IF chain, the frequency that this crystal passes through the filter is used to align the IFTs, not the SG dial reading.
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
Scott, as an aside, this is what they say for the S-20R .. they use the converter but disconnect it from upstream.
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Thanks!, I didn't look up which pin did what, I thought it could have been the plate, and pulling the tube would isolate the RF coming in. SX-62B
Scott, It is a SX-62 {no suffix} ?
Since the signal is injected on the grid, it would seem the tube would have to be in service. ??
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don??? va3drl
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Re: SX-62 alignment instructions
I did both alignments, and all seemed well until I switched in FM, and the gain was too high, and it wouldn't receive until I turned the RF control to 2-3, and only "works" in a small range, either too high, and oscillates and blanks, or too low a gain to hear
anything.
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Show quoted text
Don
Your IF alignment instructions are missing an important caveat.? You must lower the SG output to below where the AVC begins to operate.? Not doing so will cause the IFTs to be misaligned.? With the volume and RF gain controls at maximum, the SG modulation should
be heard but just barely over the background noise as the IF alignment progresses.??
Better to measure the voltage at the speaker terminals and not rely too much on one's hearing, especially as we get older, right Richard?.? This IF alignment method would be useable for all superhetrodyne receivers, not just hallicrafters.
Might as well mention that if the radio has a crystal filter in the IF chain, the frequency that this crystal passes through the filter is used to align the IFTs, not the SG dial reading.
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
On Sunday, March 16, 2025 at 01:53:14 PM CDT, don Root <drootofallevil@...> wrote:
Scott, as an aside, this is what they say for the S-20R .. they use the converter but disconnect it from upstream.
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Thanks!, I didn't look up which pin did what, I thought it could have been the plate, and pulling the tube would isolate the RF coming in. SX-62B
Scott, It is a SX-62 {no suffix} ?
Since the signal is injected on the grid, it would seem the tube would have to be in service. ??
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don??? va3drl
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Thank you, Jim. Well, I'm in Tacoma, if that's considered close to the Canadian border (+/- 3 hr drive on a good day). Shipping it to Arkansas? Return shipping would be a few times the worth of the thing, and who knows what UPS or one of their cousins would do to it, even if double boxed (as I know from experience).
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In the meantime, my SX-28 stopped working last fall and I've been avoiding it ever since. I need to take a deep breath and dive into it, but not just yet.
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Tom
On 03/16/2025 2:08 PM PDT Jim Whartenby via groups.io <old_radio@...> wrote:
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Tom
That is a shame.? I was just wondering if you had made any progress.? Perhaps a list member up in the north-west area of the country would be interested in having a go at it?? How far are you from the Canadian border?
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I'm in Arkansas over 2000 miles away from you so that would be a lot of shipping expense for me to take a look at it.? That said, the furthest I have done a repair was for a gentleman in Fukushima, Japan.
Regards,
Jim
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Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
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I certainly appreciate all the advice, hints and overall help I received in my attempt to resurrect this fine old survivor but, for me at least, I think the journey is over. Properly servicing the mixer section means that the LO coil assembly will have to be sufficiently lifted or even removed from the chassis. I found that doing so is beyond my ability. This assembly is connected to the main tuning capacitor by a connection that I am unable to de-solder in such a tight spot. It would take a heftier soldering iron than either one of the two I have, and even if I could, I doubt my ability to reconnect it. I'm a hobbyist, not a technician with the experience to deal with such a challenge.
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It's a pity--I think this receiver would be very serviceable if repaired, and be capable of performing as well as most vintage, single conversion receivers lacking a crystal filter. So, back on the shelf it goes. I'll hold on to it for a while--after all, not too many people are going to want to tackle a receiver with challenges like this one.
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Thanks again,
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Tom
On 03/09/2025 6:11 PM PDT don Root <drootofallevil@...> wrote:
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Jim & Tom?
The Hexode signal grid has a max? or min? voltage of -3? presumably to the cathode [depends who you read] , but my conclusion from a Sylvania ??blurb? is that it can go as positive as -3 volts, and as negative as -30 where there is little transconductance, and so is often connected to the AVC, but apparently not in the S-20R. but that does not help the situation.
As Jim says, on band 1 ?there is no ground, and I say there is no control of THAT grid voltage by ground, AVC or other, so it floats. On the other bands the bottoms of ?3,2,1 can be grounded [all depending] providing a DC ground ?but it goes thru the coil{s} so is strange to me. But band 1 is a real mystery to me too. ?
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Tom, I suggested a test for the bandswitch area? was it not practicle? ?
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That is interesting.? The tube manual indicates that -3 volts should be there.? Have you replaced C5 and C8?? Minor leakage in either could cancel the expected negative bias on G3 of the 6K8.? From the QST article, I expect that there are unintended interactions when the expected voltages are out of spec.
In looking at the schematic for the umpteenth time, I see how the upper band tank coils are returned to ground through switch 7D rotor that shorts the bottom of the band coils to ground.? Not sure how L13 is grounded when the band switch is in the BCB setting.? If you measure the DC resistance from the grid cap to ground you should measure R12 (33 ohms +/- 20%) plus the coil resistance for each band switch setting.? Is this the case???
Measuring from the switch side of R12, you should measure just the tank coil resistance to ground.? That resistance should increase as the band switch connects to the next lower tank coil.? If you don't see the coil resistance then perhaps the oscillator stator sections of either C1 or C2 is grounded?
Likewise, the switch side of C37 should measure the LO coil resistance to ground for each band switch setting.? Like the above, each lower band coil resistance will be higher.? Is this the case?
Remote troubleshooting is a s-l-o-w process,
Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
On Sunday, March 9, 2025 at 11:47:14 AM CDT, Allthumbs via groups.io <btse1@...> wrote:
Thank you, Jim. The 6K8 control grid (grid cap) measures 0.00 vdc, pretty much as expected.
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don??? va3drl
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don Root
Allthumbs