Re: Yet another 465B restoration question
The boards say (c)1978 so I¡¯m thinking 1979 low serial is probably closer.
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Re: Tek 2236 scope repair
Did you check or replace Q944? It's possible for it to be damaged during output transistor failure. If Q944's B-C junction blows open, it's possible for Q939 to supply enough base drive through R944 and Q944's remaining B-E, to start up and run poorly, without the current gain it would normally provide. Measure Q944's collector voltage to make sure some reasonable current is flowing through R945. Also check the base resistors R946 and 947.
Ed
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Re: Yet another 465B restoration question
The 107437 is a Tektronix Guernsey numbering - unrelated the Bxxxxxx number from Beaverton - I imagine there's a correspondence but I doubt it was documented.
You best bet is to compare the board level revisions against those the low/high Bxxxxxx manuals.
David
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Tom Phillips Sent: 13 February 2024 16:00 To: [email protected]Subject: Re: [TekScopes] Yet another 465B restoration question On Tue, Feb 13, 2024 at 04:19 AM, Don - AC2EV wrote: "How does one tell if the scope is a low serial number or a high serial number? My unit is #107437 as indicated on the front face. There¡¯s no letter indicator." The "high" serial numbers for the 465B are S/N B0600000 and up. That's how it is stated on the cover of the high S/N version of the 465B service manual. The 465B high S/N manual is marked copyright 1982. The previous version was marked copyright 1979. The leading alpha character designates the manufacturing location and I am not sure how Tek controlled the assigned numeric characters with respect to the alpha characters. Hopefully, someone can clarify that. Note that the High/Low break point is different for the 465 Model.
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I all.
I am a lucky owner of an old DSA602 From tektronix. It work fine but the batteries (Memory and CPU) are tired. On power up, the scope show an battery error.
Is anybody know what type of battery i need to replace them (techno, voltage, reference, distributor in europe). Is exist a special procedure to replace them. Is this replacement risky?
Thank's in advance for your answer.
Best regards
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Re: Tek 2236 scope repair
The scope shots in the last post were taken on the output
I probed the collector and emitter voltages and it looks like the transistor is in saturation.
The first two show the transistor emitter and collector voltages on the input side. You can see that the collector voltage (trace in yellow, with a 10x probe) goes all the way down to zero, so the transistor seems to be hard switching.
The third one shows what happens when the scope fails to start properly. The power supply oscillates at 1 MHz.
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Re: Tek 2236 scope repair
I replaced the transistors with a more matched pair (hFe for both transistors was 73 at a Vbe of 550 mV).
The circuit still does not start up reliably. There is another mode of oscillation at a few hundred kHz which the circuit sometimes falls into. I had to crank the 8.6V potentiometer all the way to get it to start.
Here are the oscilloscope captures.
There is still ringing.
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Re: Tek575 Serial No: 100082 Guernsey Ltd HV Transformer ?
Just got the pictures from the seller, it is the old type/brown one.
So not sure where to go from here and if it even make sense to start restoring it or sell it for parts (again)..
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Re: Yet another 465B restoration question
On Tue, Feb 13, 2024 at 07:59 AM, Tom Phillips wrote:
"...The "high" serial numbers for the 465B are S/N B0600000 and up..."
That should read "B060000 and up."
Apologies for the typo. I sure wish we were allowed to edit our own posts.
Cheers,
Tom
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Re: FS: Tek 453, and a few other items, near Madison, WI, USA
On Mon, Feb 12, 2024 at 02:46 PM, Eric wrote: I could be interesting in doing a pickup if there is enough to make the trip worth it. Local pickup would be ideal. I'm told there is more Tek stuff, but I haven't seen it yet. The owner now knows there's interest, so there's likely to be more info soon. -- Jim Adney Madison, WI USA
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Re: FS: Tek 453, and a few other items, near Madison, WI, USA
On Mon, Feb 12, 2024 at 02:35 PM, Dale H. Cook wrote: The subject line of this thread says "near Madison, WI, USA." And I THOUGHT I had also set that up in my sig file, but now I see that it's not there. Now it is. -- Jim Adney Madison, WI USA
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Re: Yet another 465B restoration question
On Tue, Feb 13, 2024 at 04:19 AM, Don - AC2EV wrote: "How does one tell if the scope is a low serial number or a high serial number? My unit is #107437 as indicated on the front face. There¡¯s no letter indicator."
The "high" serial numbers for the 465B are S/N B0600000 and up. That's how it is stated on the cover of the high S/N version of the 465B service manual.
The 465B high S/N manual is marked copyright 1982. The previous version was marked copyright 1979.
The leading alpha character designates the manufacturing location and I am not sure how Tek controlled the assigned numeric characters with respect to the alpha characters. Hopefully, someone can clarify that.
Note that the High/Low break point is different for the 465 Model.
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Re: Removal of Pull-tabs on older TM500 series plug-ins
I'd very carefully drill it out.? You might find that they glued the tab on the shaft.? I haven't tried to remove this kind of tab, but that's what I likely do.
Harvey
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On 2/12/2024 11:39 PM, Benjamin Badrakh wrote: Yes, it appears they glued this particular one. Even when I put my entire body weight on the pin, it wouldn't budge.
Any recommendations in this scenario?
-Benjamin
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Re: Removal of Pull-tabs on older TM500 series plug-ins
You won¡¯t be happy with the results of a ¡°cheep 3D Printer¡±.
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Re: Removal of Pull-tabs on older TM500 series plug-ins
Greetings All,
I have been using JLC3DP.com for printing my parts. Their quality and available processes are very good. They can print 316L stainless steel. Very good stuff! The pull tab parts are about $1 each in Black nylon. About $5 in 316L. A sub panel in 316L runs about $35 and $3 in white resin.
The only down side is the shipping cost.
PCBWay also offers similar services.
I was not satisfied with the parts I bought on eBay and done by my friends.
Barry
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Re: Removal of Pull-tabs on older TM500 series plug-ins
Adam:
Thanks for the link, Very nice looking replacement latch parts.
I was unaware of the inner parts, although only needed for a full replacement
As for the pull tab part, I made a bunch of these in the past and they were more than stiff enough to last, maybe even better than the originals.
ed
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Re: Yet another 465B restoration question
How does one tell if the scope is a low serial number or a high serial number?
My unit is #107437 as indicated on the front face. There¡¯s no letter indicator.
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Re: Removal of Pull-tabs on older TM500 series plug-ins
Re: Adam R. Maxwell
Wow, I didn't know such a 3D model existed for those! My school has a cheap 3D printer so I can use that to print it.
If I'm happy with how the new 3D printed version works, I may consider replacing all my TM500 plug-ins with the new 3D printed one.
Thanks!
-Benjamin
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Re: Removal of Pull-tabs on older TM500 series plug-ins
I have always hated those suckers. I've broken far more than I've saved over the years. I think in the later years a new design was adopted that could be taken apart and put back together. Probably about when TM500 was going obsolete.
Ed
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Re: Removal of Pull-tabs on older TM500 series plug-ins
On Feb 12, 2024, at 20:39 , Benjamin Badrakh <benbadr2009@...> wrote:
Yes, it appears they glued this particular one. Even when I put my entire body weight on the pin, it wouldn't budge. Barry Breaux just posted photos of a sectioned pull tab, and it looks like you might be out of luck even if you can drill that dowel out, unless the hooks spring back. Reminds me of a fox-wedged tenon. /g/TekScopes/message/203481Any recommendations in this scenario? Destructive removal and replacement with the newer three-piece latch (assuming the slot is the same size). I just 3D printed this in PETG for a TG 501 that came with a busted latch, and it works so far. I had to print a pair of them to keep the tip from overheating. Adam
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Re: Removal of Pull-tabs on older TM500 series plug-ins
Yes, it appears they glued this particular one. Even when I put my entire body weight on the pin, it wouldn't budge.
Any recommendations in this scenario?
-Benjamin
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David C. Partridge
Board
Tom Phillips
Benjamin Badrakh