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? ?I listen often to my SX-62, almost all FM. ?It takes about 7 to 10 minutes to stabilize on frequency. ?My question is that I have two peaks when I tune (88.7), ?is that sort of normal or was I just a bit sloppy when I aligned it 4 or 5 years ago?
Skip Magnuson W7WGM?
Spokane, WA
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I have an SX 42 that does the same thing. It was restored when I
got it, and I've never investigated this issue. It does have
excellent FM sensitivity and both peaks sound the same to me on an
R 42 speaker. Hope this helps.
73, Mike Gorniak, NM7X
On 11/2/2022 4:44 PM, Waldo Magnuson
via groups.io wrote:
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? ?I listen often to my SX-62, almost all FM. ?It takes about 7 to
10 minutes to stabilize on frequency. ?My question is that I have
two peaks when I tune (88.7), ?is that sort of normal or was I
just a bit sloppy when I aligned it 4 or 5 years ago?
Skip Magnuson W7WGM?
Spokane, WA
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I am not familiar with the construction of rhe SX 62 but wonder if it's possible that the rotor is going past maximum capacitance so that it's tuning higher again.? Visual inspection would probably tell.
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-------- Original message -------- From: "Waldo Magnuson via groups.io" <magnuson@...> Date: 11/2/22 2:44 PM (GMT-08:00) Subject: [HallicraftersRadios] SX-62 FM respons
? ?I listen often to my SX-62, almost all FM. ?It takes about 7 to 10 minutes to stabilize on frequency. ?My question is that I have two peaks when I tune (88.7), ?is that sort of normal or was I just a bit sloppy when I aligned it 4 or 5 years ago? Skip Magnuson W7WGM? Spokane, WA
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IF might have two peaks? and capture ratio can “lock” onto ?either ..depending on cap position Don VA3DRL ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Wednesday, November 2, 2022 6:50 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] SX-62 FM respons? I am not familiar with the construction of rhe SX 62 but wonder if it's possible that the rotor is going past maximum capacitance so that it's tuning higher again.? Visual inspection would probably tell. -------- Original message -------- From: "Waldo Magnuson via groups.io" <magnuson@...> Date: 11/2/22 2:44 PM (GMT-08:00) Subject: [HallicraftersRadios] SX-62 FM respons ? ?I listen often to my SX-62, almost all FM. ?It takes about 7 to 10 minutes to stabilize on frequency. ?My question is that I have two peaks when I tune (88.7), ?is that sort of normal or was I just a bit sloppy when I aligned it 4 or 5 years ago?
Skip Magnuson W7WGM?
Spokane, WA
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If I understand the question the double.tuning is at one frequency at the bottom of the FM band.? It seems to me that an IF problem would show up on all stations.? A problem with the oscillator should show up on AM as well.? Am I misunderstanding something?
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-------- Original message -------- From: don Root <drootofallevil@...> Date: 11/2/22 4:16 PM (GMT-08:00) Subject: Re: [HallicraftersRadios] SX-62 FM respons
IF might have two peaks? and capture ratio can “lock” onto ?either ..depending on cap position Don VA3DRL ? ? I am not familiar with the construction of rhe SX 62 but wonder if it's possible that the rotor is going past maximum capacitance so that it's tuning higher again.? Visual inspection would probably tell. -------- Original message -------- From: "Waldo Magnuson via groups.io" <magnuson@...> Date: 11/2/22 2:44 PM (GMT-08:00) Subject: [HallicraftersRadios] SX-62 FM respons ? ?I listen often to my SX-62, almost all FM. ?It takes about 7 to 10 minutes to stabilize on frequency. ?My question is that I have two peaks when I tune (88.7), ?is that sort of normal or was I just a bit sloppy when I aligned it 4 or 5 years ago?
Skip Magnuson W7WGM?
Spokane, WA
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HI Richard; he didn’t say? anything about what goes on for other stations .. But if only at the end of the dial , what you propose is possible i guess, if cap can go over the hill ?.. Don VA3DRL ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Wednesday, November 2, 2022 7:27 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] SX-62 FM respons? If I understand the question the double.tuning is at one frequency at the bottom of the FM band.? It seems to me that an IF problem would show up on all stations.? A problem with the oscillator should show up on AM as well.? Am I misunderstanding something? -------- Original message -------- From: don Root <drootofallevil@...> Date: 11/2/22 4:16 PM (GMT-08:00) Subject: Re: [HallicraftersRadios] SX-62 FM respons IF might have two peaks? and capture ratio can “lock” onto ?either ..depending on cap position Don VA3DRL ? ? I am not familiar with the construction of rhe SX 62 but wonder if it's possible that the rotor is going past maximum capacitance so that it's tuning higher again.? Visual inspection would probably tell. -------- Original message -------- From: "Waldo Magnuson via groups.io" <magnuson@...> Date: 11/2/22 2:44 PM (GMT-08:00) Subject: [HallicraftersRadios] SX-62 FM respons ? ?I listen often to my SX-62, almost all FM. ?It takes about 7 to 10 minutes to stabilize on frequency. ?My question is that I have two peaks when I tune (88.7), ?is that sort of normal or was I just a bit sloppy when I aligned it 4 or 5 years ago?
Skip Magnuson W7WGM?
Spokane, WA
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Skip:? Its too bad that you didn't get more response from others; i seem to recall this sort of thing on an EICO HFT-90 FM tuner [1959], and /or a Heathkit AR-15 stereo receiver [1969], but have no details, and did no investigation, just noted it and listened on one or the other. I still have the Heath..In sick bay, but the EICO sadly vanished long ago. Both were home built.
don VA3DRL
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I seem to recall that there's a chronic problem with bad mica caps inside the FM discriminator can. If I remember correctly, those caps can cause all kinds of strange problems with FM performance.
? ? ? ? ? ? ? ? ? ? ? ?Joe Connor
On Friday, November 4, 2022 at 12:47:29 PM EDT, don Root <drootofallevil@...> wrote:
Skip:? Its too bad that you didn't get more response from others; i seem to recall this sort of thing on an EICO HFT-90 FM tuner [1959], and /or a Heathkit AR-15 stereo receiver [1969], but have no details, and did no investigation, just noted it and listened on one or the other. I still have the Heath..In sick bay, but the EICO sadly vanished long ago. Both were home built.
don VA3DRL
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Joe; i guess you are speaking of SMD [silver mica disease] that apparently seems to make them erratic and then die shorted out and is common in many 455 kH IF transformers for AM etc.? The original posting mentioned only the one station and that it came in at two frequencies, so we don't have much to go on.
73 DON ? VA3DRL
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I don't believe SMD affects the SX-62 or SX-71, as they have the larger IF transformers that came before the miniature transformers with the Mica caps built in the base.
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Joe; i guess you are speaking of SMD [silver mica disease] that apparently seems to make them erratic and then die shorted out and is common in many 455 kH IF transformers for AM etc.? The original posting mentioned only the one station and that it came
in at two frequencies, so we don't have much to go on.
73 DON ? VA3DRL
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Scott, you're right that the SX-62 doesn't have the IF cans susceptible to SMD, but I believe the problem is plain old leakage, not SMD. I'm sure there's information on this on the various boatanchor forums. I remember reading it when I worked on my SX-62.?
? ? ? ? ? ? ? ? ? ? ? ? ? ? Joe?
On Friday, November 4, 2022 at 03:02:11 PM EDT, Scott Petersen <s-petersen@...> wrote:
I don't believe SMD affects the SX-62 or SX-71, as they have the larger IF transformers that came before the miniature transformers with the Mica caps built in the base.
Joe; i guess you are speaking of SMD [silver mica disease] that apparently seems to make them erratic and then die shorted out and is common in many 455 kH IF transformers for AM etc.? The original posting mentioned only the one station and that it came
in at two frequencies, so we don't have much to go on.
73 DON ? VA3DRL
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Scott and others
I am sticking with my first guess for now --two peaks on the IF [ If response is not flat enough]? .. but I have no conviction on that.
i agree that SMD, even if it is possible in the 62? seems to be a remote possibility
I just ran across a? somewhat similar posting on some other? group? and? i would guess from that, it is hard to rule out repeaters until they are checked out in that area.?
-- now i just saw a new email from Joe? and after a few moments of thought, it could be that old caps change value a bit and UNTUNE the IF’s rather than fail shorted .. but that is still just one possibility. ? 73,, don?? VA3DRL ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Scott Petersen
Sent: Friday, November 4, 2022 3:02 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] SX-62 FM respons? I don't believe SMD affects the SX-62 or SX-71, as they have the larger IF transformers that came before the miniature transformers with the Mica caps built in the base.
Joe; i guess you are speaking of SMD [silver mica disease] that apparently seems to make them erratic and then die shorted out and is common in many 455 kH IF transformers for AM etc.? The original posting mentioned only the one station and that it came in at two frequencies, so we don't have much to go on.
73 DON ? VA3DRL
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I still sm not clear on a couple of things.? Is the double peak on one station only?? And secondly how are you seeing it?? I thought the 62 does not have a tuning indicator, am I wrong?? ?A problem with the IF or detector should show up on all stations.? If this appears on one station it is something else ?
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-------- Original message -------- From: don Root <drootofallevil@...> Date: 11/4/22 1:35 PM (GMT-08:00) Subject: Re: [HallicraftersRadios] SX-62 FM respons
Scott and others
I am sticking with my first guess for now --two peaks on the IF [ If response is not flat enough]? .. but I have no conviction on that.
i agree that SMD, even if it is possible in the 62? seems to be a remote possibility
I just ran across a? somewhat similar posting on some other? group? and? i would guess from that, it is hard to rule out repeaters until they are checked out in that area.?
-- now i just saw a new email from Joe? and after a few moments of thought, it could be that old caps change value a bit and UNTUNE the IF’s rather than fail shorted .. but that is still just one possibility. ? 73,, don?? VA3DRL ? ? I don't believe SMD affects the SX-62 or SX-71, as they have the larger IF transformers that came before the miniature transformers with the Mica caps built in the base.
Joe; i guess you are speaking of SMD [silver mica disease] that apparently seems to make them erratic and then die shorted out and is common in many 455 kH IF transformers for AM etc.? The original posting mentioned only the one station and that it came in at two frequencies, so we don't have much to go on.
73 DON ? VA3DRL
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jan 18 ? attempting to edit??? original which mostly went into "quoted text" i have got this topic still dangling in my drafts-unresolved basket ..and am trying to get closer to an answer. On Fri, Nov 4, 2022 at 02:12 PM, Richard Knoppow wrote:
- I still am not clear on a couple of things.? Is the double peak on one station only?? And secondly how are you seeing it?? I thought the 62 does not have a tuning indicator, am I wrong?? ?A problem with the IF or detector should show up on all stations.? If this appears on one station it is something else
Richard; I believe he does not need to see it with a tuning meter; as one tunes, the station audibly becomes fairly clear then becomes weak and/or distorted, then becomes clear again.. that's from my memory of some stations back in the late 1950's I bypass the other fragments for now. Re: an earlier comment...Re:" the rotor is going past maximum"...
- I am not familiar with the construction of the SX-62 but wonder if it's possible that the rotor is going past maximum capacitance so that it's tuning higher again.? Visual inspection would probably tell.
Richard; you really pulled the wool over my eyes, and i guess the others too..I've been conned!, cant think!!! It seems to me the frequency of 88.7? is close to the bottom of the official new FM band [ center frequency = 87.9?MHz ], as we knew it? after 1945, but we hardly need to inspect the tuning cap; just look at the SX-62's specs or better, just look at the dial scale. i clearly see it starting before 54 Mcees and ending just over 108 Mcees ----so 88.7 will be near mid range of the sx-62 scale, so the tuning cap must be near mid rotation; nowhere near the end of "normal-nice-curve" of capacitance vs degrees of rotation. also; you likely meant "below minimum", not "past maximum" , which could also apply.? Now, I somewhat? agree, with some suggestions that the problem might be in the IF, and due to bad alignment, or some IF cap [not SMD] shifted, but we expect double tuning all over the FM band, and we never had any input from Waldo? on that.. I am going out on a limb to suggest an alternative: especially if the signal is weak, the limiter action are is poor, and normal Fm detection fails, but the wide side slopes of the old IF circuits, will allow [AM] slope detection when tuned to either above or below the center frequency. Likely, poor tuning of the IF will make this more likely.. 73 don VA3DRL?
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On Sun, Jan 15, 2023 at 03:13 PM, don Root wrote:
73 don VA3DRL?
re what i just posted ... somehow it all ended up under "quoted text" dunnoWatImdoin 73 don VA3DRL?
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For some reason I could not get the SX-62 to play FM broadcast as good
as a cheap table radio, I was disappointed that a radio as nice as the 62 couldn't beat a tabletop. I have 2 of them, both pretty much the same.
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On Sun, Jan 15, 2023 at 03:13 PM, don Root wrote:
73 don VA3DRL?
re what i just posted ... somehow it all ended up under "quoted text"
dunnoWatImdoin
73 don VA3DRL?
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On Sun, Jan 15, 2023 at 03:55 PM, Scott Petersen wrote:
For some reason I could not get the SX-62 to play FM broadcast as good as a cheap table radio, I was disappointed that a radio as nice as the 62 couldn't beat a tabletop. I have 2 of them, both pretty much the same.
Scott, mine is still in sick bay, so i cant say either way, but I wonder if you have a reasonable antenna as was needed/expected back then? ? newer? table tops often are designed for an internal whip. you didn't mention if you had weak signals or poor audio on the 62. hope maybe you can get it performing. 73 Don VA3DRL
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The audio is a bit muffled, the signal has 2 closely spaced narrow peaks,
but even when the clearest peak is selected, the audio is not strong and clear, I think I've heard it has something to do with the bandwidth of the IF transformers, and the compromise of narrow band FM.
Signal reception is good, but it is only a guess as there is no signal
meter on the 62
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On Sun, Jan 15, 2023 at 03:55 PM, Scott Petersen wrote:
For some reason I could not get the SX-62 to play FM broadcast as good as a cheap table radio,
I was disappointed that a radio as nice as the 62 couldn't beat a tabletop. I have 2 of them, both pretty much the same.
Scott, mine is still in sick bay, so i cant say either way, but I wonder if you have a reasonable antenna as was needed/expected back then? ?
newer? table tops often are designed for an internal whip.
you didn't mention if you had weak signals or poor audio on the 62.
hope maybe you can get it performing.
73 Don VA3DRL
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The FM on the SX-62 should give you great audio quality. ?If not, the FM IF chain?may need re-alignment or something else is wrong. ?
73 - Steve, KW4H?
Sent from Proton Mail for iOS
On Sun, Jan 15, 2023 at 5:22 PM, Scott Petersen < s-petersen@...> wrote:
The audio is a bit muffled, the signal has 2 closely spaced narrow peaks,
but even when the clearest peak is selected, the audio is not strong and clear, I think I've heard it has something to do with the bandwidth of the IF transformers, and the compromise of narrow band FM.
Signal reception is good, but it is only a guess as there is no signal
meter on the 62
On Sun, Jan 15, 2023 at 03:55 PM, Scott Petersen wrote:
For some reason I could not get the SX-62 to play FM broadcast as good as a cheap table radio,
I was disappointed that a radio as nice as the 62 couldn't beat a tabletop. I have 2 of them, both pretty much the same.
Scott, mine is still in sick bay, so i cant say either way, but I wonder if you have a reasonable antenna as was needed/expected back then? ?
newer? table tops often are designed for an internal whip.
you didn't mention if you had weak signals or poor audio on the 62.
hope maybe you can get it performing.
73 Don VA3DRL
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toggle quoted message
Show quoted text
The FM on the SX-62 should give you great audio quality. ?If not, the FM IF chain?may need re-alignment or something else is wrong. ?
73 - Steve, KW4H?
Sent from Proton Mail for iOS
On Sun, Jan 15, 2023 at 5:22 PM, Scott Petersen < s-petersen@...> wrote:
The audio is a bit muffled, the signal has 2 closely spaced narrow peaks, but
even when the clearest peak is selected, the audio is not strong and clear, I think I've heard it has something to do with the bandwidth of the IF transformers, and the compromise of narrow band FM.
Signal reception is good, but it is only a guess as there is no signal meter on
the 62
On Sun, Jan 15, 2023 at 03:55 PM, Scott Petersen wrote:
For some reason I could not get the SX-62 to play FM broadcast as good as a cheap table
radio, I was disappointed that a radio as nice as the 62 couldn't beat a tabletop. I have 2 of them, both pretty much the same.
Scott, mine is still in sick bay, so i cant say either way, but I wonder if you have a reasonable antenna as was needed/expected back then? ?
newer? table tops often are designed for an internal whip.
you didn't mention if you had weak signals or poor audio on the 62.
hope maybe you can get it performing.
73 Don VA3DRL
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don Root