Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Weird Shit
84 views
Skip to first unread message
Jeff Urban
Jul 7, 2020, 9:02:23 PM7/7/20
to
I work on vintage audio. A but slow now but I am fine, I won't starve.
Anyway, lately I have been seeing very weird failures. It always used to be outputs and drivers. People beat on them running them under a rug and burning it up, shit like that. Or they had lower impedance speakers ad the amp was too wimpy. Whatever.
Now that this is all old the failure modes changed. We got three modes now.
The first is referred to as infant mortality. Some parts are simply no good ad they fail soon and it is all under warranty usually. The company will get them elsewhere.
Next comes normal failure. Zero to a hundred degrees all the time, that can take its toll. that was the usual outpts ad drivers.
Now with this stuff approaching fifty years old, it is not just a matter of bad caps. We are talking stupid ass resistors, standard diodes that the PC board glue ate up the leads, shit like this. Some obscure transistor nobody even knew the thing had.
The business is not what it used to be. "Order some 2SDXXX ad 2SB xxx and a 2SCXXX and the rest of it we got. Not no more.
For example, I forget the model now but the diff pair had all negative voltages, but there was no sound and no significant DC offset. The diode for the current source to the emitters of the diff pair was open. Who would ever have thunk that ?
Mechanical things are even worse, I won't even work on cassette decks anymore. I'll do some of the better turntables and reel to reels.
Yeah, a week or so ago I emailed a client with "I don't know if you can afford the parts for this, EIGHT CENTS".
That is what it is, you can't fix the new shit and the old shit takes some real skill sometimes. Like 25 years ago "Blown channel, we got 3281s and 1302s ? Not no more.
Anyway, lately I have been seeing very weird failures. It always used to be outputs and drivers. People beat on them running them under a rug and burning it up, shit like that. Or they had lower impedance speakers ad the amp was too wimpy. Whatever.
Now that this is all old the failure modes changed. We got three modes now.
The first is referred to as infant mortality. Some parts are simply no good ad they fail soon and it is all under warranty usually. The company will get them elsewhere.
Next comes normal failure. Zero to a hundred degrees all the time, that can take its toll. that was the usual outpts ad drivers.
Now with this stuff approaching fifty years old, it is not just a matter of bad caps. We are talking stupid ass resistors, standard diodes that the PC board glue ate up the leads, shit like this. Some obscure transistor nobody even knew the thing had.
The business is not what it used to be. "Order some 2SDXXX ad 2SB xxx and a 2SCXXX and the rest of it we got. Not no more.
For example, I forget the model now but the diff pair had all negative voltages, but there was no sound and no significant DC offset. The diode for the current source to the emitters of the diff pair was open. Who would ever have thunk that ?
Mechanical things are even worse, I won't even work on cassette decks anymore. I'll do some of the better turntables and reel to reels.
Yeah, a week or so ago I emailed a client with "I don't know if you can afford the parts for this, EIGHT CENTS".
That is what it is, you can't fix the new shit and the old shit takes some real skill sometimes. Like 25 years ago "Blown channel, we got 3281s and 1302s ? Not no more.
peterw...@gmail.com
Jul 8, 2020, 8:16:39 AM7/8/20
to
Wait until you start seeing low-end phenolic boards - mostly from Pacific Rim stuff - start to turn to powder. Or metal-fatigue on solid-wire connections.
On the other hand, we have better materials, better glues, better solvents, better lubricants, better belt materials - just plain better chemistry - and so forth.
Most of the stuff I deal with is either point-to-point vintage radios from pre-WWII, Zenith TransOceanics, or 1960s/70s US/Euro audio stuff. So far, so good on getting parts as needed.
Peter Wieck
Melrose Park, PA
On the other hand, we have better materials, better glues, better solvents, better lubricants, better belt materials - just plain better chemistry - and so forth.
Most of the stuff I deal with is either point-to-point vintage radios from pre-WWII, Zenith TransOceanics, or 1960s/70s US/Euro audio stuff. So far, so good on getting parts as needed.
Peter Wieck
Melrose Park, PA
Jeff Urban
Jul 8, 2020, 10:04:24 AM7/8/20
to
Man I like that old shit. Friend of mine is even worse.
Talk about old shit ? Alright, an HP VTVM, I THINK a 412A. This thing has four lightbulbs in it and a spinning disk that somehow tells it the reading. The range of this thing is almost incredible, and the input impedance is non existent. We are talking 100 meg on many of the ranges. Those ranges are really out of this world, down to millivolts full scale n shit. Look up the specs. You might just throw that Fluke in the trash.
He won't sell it. Fucker.
But this is a prime example of something that is older and better and that they probably can't even build today.
And that is progress.
Talk about old shit ? Alright, an HP VTVM, I THINK a 412A. This thing has four lightbulbs in it and a spinning disk that somehow tells it the reading. The range of this thing is almost incredible, and the input impedance is non existent. We are talking 100 meg on many of the ranges. Those ranges are really out of this world, down to millivolts full scale n shit. Look up the specs. You might just throw that Fluke in the trash.
He won't sell it. Fucker.
But this is a prime example of something that is older and better and that they probably can't even build today.
And that is progress.
peterw...@gmail.com
Jul 8, 2020, 10:15:33 AM7/8/20
to
https://www.mercari.com/us/item/m47623413470/?gclsrc=aw.ds&utm_source=google&utm_medium=cpc&utm_campaign=2065917279&utm_content=t0&adgroup=78855541600&network=g&device=c&merchant_id=189924233&product_id=m47623413470&product_id=527918100373&gclid=Cj0KCQjw3ZX4BRDmARIsAFYh7ZL03v9YhvN8j22nd7sMbQWqsq07LkLQqKlcht_Boa52NtNzvcTZxhcaArUAEALw_wcB
Not that hard to find. The internet is your friend.
Not that hard to find. The internet is your friend.
Jeff Urban
Jul 8, 2020, 10:22:54 AM7/8/20
to
Hey, do you have anything that gets the forbidden bands ?
Those are the bands that are omitted on most SW radios sold here because they are supposed to be for foreign audiences. You have to pay extra to get those.
That reminds me of something fro the 1980s. We hired this Black guy at the shop (he was surprised) and he said he would like to make a all band receiver. From zero to as high as it gets, or at least got back then. I like the idea actually. but now that I know more about engineering and all that I know how much of a pain in the ass it would be. It is easy to just say "Do it" but it is not quite as easy to do it.
I learned alot in the last 25 years or so, they can't do this and that. They would love to because their pockets would be busting out with money.
Like, alright politics but not too much. One party in the US wants to mandate all kinds of shit about new energy sources. They don't realize that there are people working on that. BECAUSE THEY WANT TO BE THE ONES WHO SELL IT. there is no more power than money. A fuckig corporation, they don't give a fuck about the law, they give a fuck if they can get sued. Some of you have been there.
>start to turn to powder
I have never seen that but I guess I believe you. Why would you make it up ? Maybe you are working on things that are older and my little experience has not reached that point. Well, whaddya gonna do ?
But you would love some of the old shit my friend has. I was thinking of telling him to put me in his will for a few things but he might outlive me.
An HP 412A and he fixed it without my help. Damn. I am so useless.
Those are the bands that are omitted on most SW radios sold here because they are supposed to be for foreign audiences. You have to pay extra to get those.
That reminds me of something fro the 1980s. We hired this Black guy at the shop (he was surprised) and he said he would like to make a all band receiver. From zero to as high as it gets, or at least got back then. I like the idea actually. but now that I know more about engineering and all that I know how much of a pain in the ass it would be. It is easy to just say "Do it" but it is not quite as easy to do it.
I learned alot in the last 25 years or so, they can't do this and that. They would love to because their pockets would be busting out with money.
Like, alright politics but not too much. One party in the US wants to mandate all kinds of shit about new energy sources. They don't realize that there are people working on that. BECAUSE THEY WANT TO BE THE ONES WHO SELL IT. there is no more power than money. A fuckig corporation, they don't give a fuck about the law, they give a fuck if they can get sued. Some of you have been there.
>start to turn to powder
I have never seen that but I guess I believe you. Why would you make it up ? Maybe you are working on things that are older and my little experience has not reached that point. Well, whaddya gonna do ?
But you would love some of the old shit my friend has. I was thinking of telling him to put me in his will for a few things but he might outlive me.
An HP 412A and he fixed it without my help. Damn. I am so useless.
peterw...@gmail.com
Jul 8, 2020, 10:42:18 AM7/8/20
to
The Grundig Satellit 700 gets the "forbidden bands".
The Zenith RD7000Y also gets them, along with the US Weather Band. I keep both.
It is entirely legal to *receive* any transmission from any source in the United States, as the "people" own the airwaves.
It is NOT entirely legal to transmit on certain frequencies - where this gets awkward is with super-het sets receiving some signals - as super-het sets also 'transmit' in the process. Look it up.
During WWII, the US military through proxies, routinely crippled SW sets owned by foreigners in the US.
Only Italy and Saudi Arabia (in the so-called 'free' world) would forbid the manufacture or sale of SW receivers capable of receiving certain frequencies. Of course, China, the USSR, and once-up-a-time Cuba do so today, and India severely limits amateur bands.
Peter Wieck
Melrose Park, PA
p.s.: Funny thing, though - I purchased my Grundig NIB in a Souk in Al Khobar, along with 18 others that I distributed around the world, and which paid for two very elaborate vacations for my wife and me.
The Zenith RD7000Y also gets them, along with the US Weather Band. I keep both.
It is entirely legal to *receive* any transmission from any source in the United States, as the "people" own the airwaves.
It is NOT entirely legal to transmit on certain frequencies - where this gets awkward is with super-het sets receiving some signals - as super-het sets also 'transmit' in the process. Look it up.
During WWII, the US military through proxies, routinely crippled SW sets owned by foreigners in the US.
Only Italy and Saudi Arabia (in the so-called 'free' world) would forbid the manufacture or sale of SW receivers capable of receiving certain frequencies. Of course, China, the USSR, and once-up-a-time Cuba do so today, and India severely limits amateur bands.
Peter Wieck
Melrose Park, PA
Tim R
Jul 8, 2020, 11:15:12 AM7/8/20
to
On Wednesday, July 8, 2020 at 10:22:54 AM UTC-4, Jeff Urban wrote:
> Hey, do you have anything that gets the forbidden bands ?
>
> Those are the bands that are omitted on most SW radios sold here because they are supposed to be for foreign audiences. You have to pay extra to get those.
>
SDR. DC to Daylight.
> Hey, do you have anything that gets the forbidden bands ?
>
> Those are the bands that are omitted on most SW radios sold here because they are supposed to be for foreign audiences. You have to pay extra to get those.
>
You're still going to have to build an antenna tuner I imagine.
John-Del
Jul 8, 2020, 2:14:54 PM7/8/20
to
On Wednesday, July 8, 2020 at 10:42:18 AM UTC-4, pf...@aol.com wrote:
> The Grundig Satellit 700 gets the "forbidden bands".
> The Zenith RD7000Y also gets them, along with the US Weather Band. I keep both.
>
> It is entirely legal to *receive* any transmission from any source in the United States, as the "people" own the airwaves.
> It is NOT entirely legal to transmit on certain frequencies - where this gets awkward is with super-het sets receiving some signals - as super-het sets also 'transmit' in the process. Look it up.
> During WWII, the US military through proxies, routinely crippled SW sets owned by foreigners in the US.
My grandparents were legal U.S. immigrants from Italy, and they had to bring their radio to a local radio shop to have the SW defeated during the war - *while* my dad (their son) was fighting in the Third Armored Division and collecting 5 battles stars in the effort. My understanding was that both my grandparents had achieved their citizenship by the time the war started. Weird time, but at least there was no relocation for them.
> The Grundig Satellit 700 gets the "forbidden bands".
> The Zenith RD7000Y also gets them, along with the US Weather Band. I keep both.
>
> It is entirely legal to *receive* any transmission from any source in the United States, as the "people" own the airwaves.
> It is NOT entirely legal to transmit on certain frequencies - where this gets awkward is with super-het sets receiving some signals - as super-het sets also 'transmit' in the process. Look it up.
> During WWII, the US military through proxies, routinely crippled SW sets owned by foreigners in the US.
Allodoxaphobia
Jul 8, 2020, 2:43:06 PM7/8/20
to
On Wed, 8 Jul 2020 07:04:20 -0700 (PDT), Jeff Urban wrote:
> Man I like that old shit. Friend of mine is even worse.
heh... I'm pretty old shit, myself. :-)
> Man I like that old shit. Friend of mine is even worse.
I have and still use from time-to-time an old
James Millen Grid Dip Meter model 90651 -- that uses the old "acorn" tubes.
https://www.radiomuseum.org/r/millen_grid_dip_meter_90651.html
https://en.wikipedia.org/wiki/955_acorn_triode
Tho', I most often use an old Heathkit Tunnel Dipper.
https://www.radiomuseum.org/r/heath_tunnel_dipper_hm_10_a_hm1.html
I have an old BC-221 frequency generator that I still put to use.
http://www.richardsradios.co.uk/bc221.html
Jonesy
--
Marvin L Jones | W3DHJ | W3DHJ | https://W3DHJ.net/
Pueblo, Colorado | @ | Jonesy | __ linux FreeBSD
38.238N 104.547W | jonz.net | DM78rf | 73 SK
Jeff Urban
Jul 10, 2020, 4:43:51 PM7/10/20
to
If I may be so bold as to get back to the topic... (I am not bitching, we cool)
"We" got a whole bunch of CROs. New scopes are LCD so they are old. They are getting the same way. Problems you wouldn't fucking believe.
We got a nice Kikusui, this thing runs like a Tek, but now it has a fault all the sudden. My cohort is trying to get it back up, he foud a few voltages low, once he adjusted them he got his trace beck but it won't calibrate.
It is weird, the HV is low but the trace is too small. Lower HV increases deflection sensitivity so what now ?
(Kikusui COS6100A)
The HV runs off the 12 volts. It has the usual multiplier for the HV, in this case a sextupler. It does not have direct feedback, just regulates from the front. (that means just by sampling the transformer pulses, no big resistor) that voltage was low, he adjusted it up and got horizontal sweep back.
Now how the hell can that happen ? the two have noting to do with each other. Except for that 12 volt source maybe, but he knows how to measure that, in fact I think he said it was 11.8 or something the should not keep it from working.
These are nice scopes. I like them better than some Teks, well the 2200 series. I don't care for them at all but would use them at gunpoint. I mean with no alternative I am sure they are fine, but I just don't like them. They don't have that Tek feel, but the Kiks do. A little bit different but still, Man they got split on the delayed time base, the controls are well layed out. We got an HP 1725A which cost a bunch more but at twice the price I would take the Kik.
In fact that 1725A, it has a haze. The trace is actually sharp but there is like a halo around it. there is a mesh in the CRT and I checked the voltage to it. It is probably a defective CRT. We got one I think, there was one that needed the vertical output and that is unobtainium. It was not much prioritized because we got others.
i actually built a vertical circuit for the other one and it worked. Frequency response was great, linear, all that - but not enough gain. I could not find a way to increase it and I got the best transistors I could find. It just would not calibrate because there was not enough range, and that means there was not enough gain ahead of it to compensate.
But you should have seen the 50MHz square wave on that thing. In fact they also have 50 ohm termination built in.
When anything gets old things get weird. Like my Jimmy. nice in some ways and nice and tough for the shit roads, and 4WD. i let it go because it needed yet ANOTHER radiator, tires, brakes, injectors and it was a Vortec which meas the cost ten times more. But what REALLY did it was the wiring. The switch did not work to pop the rear window, but it did pop when you put it in reverse. That was "Man I do not want to even try to deal with this".
HA, I had roomies at the time and let them drive it sometimes. I do not set the stations on the radio, it is along with me not wearing clothes with writing on them, I will tell you my views if I choose. I am not a billboard. Anyway, I made the guy go and find the right fuse to pull to return it to factory. "And no disconnecting the battery, I don't want the computer to have to relearn everything".
But it really was getting weird. And my Buick, I liked that car but towards the end same shit. Weird wiring problems. First it was the fuel pump, I had my wrench just wire it to "IGN". then the heater. the HEATER ? That wiring does not go to the back, there is no reason for it to screw up. But it did. Don't think I couldn't afford a good(er) car, I didn't want one. All but a few cars, I consider disposable. i mean the big block V8s, yeah I want to keep them. But the rest ? Even this Park avenue the engine eventual fell out of which was a nice comfortable car that drove really well was only a V6.
When things get old. One nice thing is it is making me get better at my skills. Troubleshooting. I no longer assume anything.
"We" got a whole bunch of CROs. New scopes are LCD so they are old. They are getting the same way. Problems you wouldn't fucking believe.
We got a nice Kikusui, this thing runs like a Tek, but now it has a fault all the sudden. My cohort is trying to get it back up, he foud a few voltages low, once he adjusted them he got his trace beck but it won't calibrate.
It is weird, the HV is low but the trace is too small. Lower HV increases deflection sensitivity so what now ?
(Kikusui COS6100A)
The HV runs off the 12 volts. It has the usual multiplier for the HV, in this case a sextupler. It does not have direct feedback, just regulates from the front. (that means just by sampling the transformer pulses, no big resistor) that voltage was low, he adjusted it up and got horizontal sweep back.
Now how the hell can that happen ? the two have noting to do with each other. Except for that 12 volt source maybe, but he knows how to measure that, in fact I think he said it was 11.8 or something the should not keep it from working.
These are nice scopes. I like them better than some Teks, well the 2200 series. I don't care for them at all but would use them at gunpoint. I mean with no alternative I am sure they are fine, but I just don't like them. They don't have that Tek feel, but the Kiks do. A little bit different but still, Man they got split on the delayed time base, the controls are well layed out. We got an HP 1725A which cost a bunch more but at twice the price I would take the Kik.
In fact that 1725A, it has a haze. The trace is actually sharp but there is like a halo around it. there is a mesh in the CRT and I checked the voltage to it. It is probably a defective CRT. We got one I think, there was one that needed the vertical output and that is unobtainium. It was not much prioritized because we got others.
i actually built a vertical circuit for the other one and it worked. Frequency response was great, linear, all that - but not enough gain. I could not find a way to increase it and I got the best transistors I could find. It just would not calibrate because there was not enough range, and that means there was not enough gain ahead of it to compensate.
But you should have seen the 50MHz square wave on that thing. In fact they also have 50 ohm termination built in.
When anything gets old things get weird. Like my Jimmy. nice in some ways and nice and tough for the shit roads, and 4WD. i let it go because it needed yet ANOTHER radiator, tires, brakes, injectors and it was a Vortec which meas the cost ten times more. But what REALLY did it was the wiring. The switch did not work to pop the rear window, but it did pop when you put it in reverse. That was "Man I do not want to even try to deal with this".
HA, I had roomies at the time and let them drive it sometimes. I do not set the stations on the radio, it is along with me not wearing clothes with writing on them, I will tell you my views if I choose. I am not a billboard. Anyway, I made the guy go and find the right fuse to pull to return it to factory. "And no disconnecting the battery, I don't want the computer to have to relearn everything".
But it really was getting weird. And my Buick, I liked that car but towards the end same shit. Weird wiring problems. First it was the fuel pump, I had my wrench just wire it to "IGN". then the heater. the HEATER ? That wiring does not go to the back, there is no reason for it to screw up. But it did. Don't think I couldn't afford a good(er) car, I didn't want one. All but a few cars, I consider disposable. i mean the big block V8s, yeah I want to keep them. But the rest ? Even this Park avenue the engine eventual fell out of which was a nice comfortable car that drove really well was only a V6.
When things get old. One nice thing is it is making me get better at my skills. Troubleshooting. I no longer assume anything.
Cydrome Leader
Jul 12, 2020, 1:28:11 AM7/12/20
to
heating elements bug me the most. Not sure how they age. Other fuses
sometimes just seem to die too. Remember when cheap-o imported AGC type
fuses touted "electronically tested" on the packages? Guess it's nice to
get 5 fuses out of a pack of 5 that work.
Just had the solid wire break off a crimp terminal as I flipped some over
180 degrees to put on more cover screws. That's annoying.
Anybody know what's in that beige "glue" all over 1980s electronics,
usually on ribbon cables soldered directly to a board, like on receivers
with digital displays? It's somtimes porous and seems to get way harder
with time. Those ribbons cables seem to have a 3 flex endurance as well.
They're the completely tinned ones just stiff enought ot press into some
connectors.
0 new messages