polypropylene caps failures ?
from Tim P (UK)
Having another look at my 5116 with no HV (the one blowing the 5R1 resistor
in the oscillator). Before I delve in the output HV side (with appropriate
precautions !!!!!), are there any 'usual suspects'? ie the polyprop
capacitors in the filter circuit or the HV rectifier from the transformer
secondary? A quick unpowered continuity check shows no shorts to ground.
The polyprops are Sprague 6KV. White, black lettering, yellow ends.
many thanks
Tim
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Re: 152-0310-00 replacement
Well, apparently these are the 151-0130-00 diodes in DO-17 package, same diodes as all 4 in my 454. These are soldered and I suspect deliberately with the number down since I also could read part of the number in one case only. I have seen the clip-type packages for instance in 3T77(A) plugins. Much later 454s used TD-3A (1N3717) DO-17 diodes but only in the sweep circuits.
Albert
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On Fri, Mar 8, 2019 at 07:29 AM, SR77 wrote:
I opened up the scope and the parts in question are small and completely gold
in colour with two leads also gold in colour. I¡¯m not sure if I got all the
writing but I managed to see ¡°0310GE¡± written on them. So, which ones do I
have in my scope?
(I had tried to post this the other day but it doesn¡¯t seem to have made
through. I apologize if it eventually does!)
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Hi there: Have a nice 2467B, before any CAL, adjusting CRT.
Its fine but there is a 1/10 div upward bending of horizontal lines at the upper right.
In all other respects the CRT display is fine.
At lower and middle lines are straight.
I did trace rotation, which is OK, so this is a distortion.
Use geometry trimmer, R4350, distortion only gets worse and screen scale changes.
Best adjustment is original position, full CCW.
Anyone have experience in geometry problems?
I Need to fix this before I can do a CAL!
Many thanks
Jon
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Peter, trace is central, doesn't move at all with plugin controls. Just a nice sharp? horizontal line. Time base is fine, focus etc are perfect. The "up" trace finder is lit permanently. Plug in controls have no effect. No chop or dual trace. Rich On Fri, 8 Mar 2019 at 13:57, Peter H<p.holzleitner@...> wrote: Where on the screen is the trace?? Do the vertical position controls have any effect (even just on the neons?), and when you use alt or chop do you get a dual trace?
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Nenad, thanks for your suggestions.I shall do those checks you suggest. I don't have a spare plugin. I will also test the valves in the vertical amplifier area, and check voltages there. Avo MK3 tester will get some use!The scope has been stored dry and in a clean area? Rich On Fri, 8 Mar 2019 at 9:17, Nenad Filipovic<ilmuerte@...> wrote: Switches and contacts. If you have another vertical plugin, try it. The biggest issue witch these old scopes is dirt and patina on electrical contacts and switches, so: - Give plenty of workout to all controls (rock every knob back and forth many times) while observing the trace on a powered scope. Noisy contacts will clearly reveal themselves. - Check/clean the plug of the vertical plugin (both male and female part). - Re-seat the tubes. Check if tube pins show signs of corrosion. Visual inspection of the state of switches (corrosion, patina) could indicate if the whole instrument suffered from humidity and requires restoration of switches. This is recommended for such old instruments, but you may get away without that if the instrument was carefully preserved in dry environment. Nice scope though. Wish I had a 581/585 to restore... Best Regards, Nenad Filipovic On Fri, Mar 8, 2019 at 8:35 AM Rich Collins via Groups.Io <richanny= [email protected]> wrote:
My old 581a scope with 82 plug in hasn't been used for a year and when
switched on, there was no vertical response, just a horizontal trace. The
time base is working fine.The neon indicator is showing the trace is
up.I've never had to repair it in the 30 years I've owned it!I have the
service manuals. Any advice on what to check initially?
Rich
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Where on the screen is the trace? Do the vertical position controls have any effect (even just on the neons?), and when you use alt or chop do you get a dual trace?
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Re: 465 timebase switch fingers not soldered completely?
Thanks for your advice. I have left them as-is, other than cleaning the contacts and re-aligning the a&b timebase knobs.
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Re: tektronix 475 help power supply
Is the fan working OK? If the fan stalls due to age and lack of lubrication or due to mechanical damage (mine was damaged around the fan filter on the rear panel) it will draw too much current from the +15V supply and force the +15V regulator into current limiting mode. It still caused CR1442 to fail on my 475. You can temporarily disconnect the fan at the two pin connector on the fan PCB.
Roger
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Re: Source for 4-40 UNC pan head pozidriv machine screws
It turns out that the actual source for these was:
ACT (Fasteners and Components) Ltd.
Unit 13
Four Ashes Industrial Estate
Station Road
Wolverhampton WV10 7DB
Phone 01902 791880
Hth
David
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of David C. Partridge Sent: 27 February 2019 15:41 To: [email protected]Subject: Re: [TekScopes] Source for 4-40 UNC pan head pozidriv machine screws I'm just waiting for confirmation, but Modern Screws seem to have come up trumps! Web: <www.modern-screws.co.uk> Email: sales@... Not dagger cheap, but beggars can't be choosers! Cheers David -----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of george edmonds via Groups.Io Sent: 27 February 2019 14:02 To: [email protected]Subject: Re: [TekScopes] Source for 4-40 UNC pan head pozidriv machine screws Hi Dave How many do you want, I have a scrap 465 which you can have the screws from. They are 4-40 Pozi unc with captive washers. Regards George On Wednesday, February 27, 2019 1:47 PM, David C. Partridge <david.partridge@...> wrote: So far it appears that no-one in the UK has these in Pozidriv, only in Phillips. (Pan head Pozidriv, 4-40 1/4" and 3/16" long) Does anyone know of a source outside UK? All the screws in a 7000 series 'scope are Pozidriv UNC (and maybe some UNF), so someone must have made them ... Dave
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Re: 2465B fan replacements?
Hi Jon, This was the subject of a thread back in 2016. The title of the thread was " 2465B fan replacement". This was one reply. Colin. Here is fan info, anyone have a fan to spare or where to get them? TEK part 1192102-00
12V 1.5W 3200 RPM 24 CFM 3.5" x 1" Seems these can work:
NMB Technologies Corp. #3108NL-04W-B30-P00.
Nidec, Mod. D08G-12TH MANY THANKS!
Jon -----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Jean-Paul Sent: 07 March 2019 20:25 To: [email protected]Subject: Re: [TekScopes] 2465B fan replacements? Hello all, anyone have the exact or best DigiKey or Mouser part number to replace the fans, I opened the fan hub and oiled, they are better but still noise and one is not reliably starting. I recall the forum had a good SKU. Many thanks Jon
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tektronix 475 help power supply
hello to the group the problem that the oscilloscope turns on and it works but after a few minutes it breaks Q1446 2n2222 and the rectifier CR1442 warms the line + 15v, the electrolytics have already been replaced
Robertp
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Re: 465 timebase switch fingers not soldered completely?
Hi,
I think this is supposed to be like that. I had one otherwise quite
expensive TM500 module (maybe an SG503?) that I got for nearly nothing,
because someone dropped it onto its face and besides bending the faceplate,
the drum for the range switches was pushed inwards and bent nearly all the
switch contacts.
Initially this seamed like a disaster, but then to my great surprise I
found out that they were in fact not bent, but simply rotated and I could
actually rotate the contacts back around the point they were fastened to
the PCB. So to me it looks like they are actually socketed in same way.
I did not dare to experiment more, like trying to pull them out, because I
was happy to move them back to the original position and the module lives
happily ever after. Of course I had to fox other damage, but the switches
were surprisingly easy to fix.
Szabolcs
<bbortnick@...> ezt ¨ªrta (id?pont: 2019. m¨¢rc. 7., Cs, 18:49):
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Hi all,
Now working on the cranky timebase rotary switch. After pulling out the
timing board (not hard; skip step 2.c - remove 3 wire cable - as it's
redundant with step 3 which removes the other end of the cable from the A
TRIG HOLDOFF pot.)
Found the inner knob was off by 2 notches, so could not turn into x-y
mode. Easy adjustment with the knob's grub screws.
However I see that a number of the fingers appear to not be soldered
properly to the top of the board (see linked photo).
/g/TekScopes/album?id=86374
Should I re-solder all of these?
Thanks for the help!
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Re: 465 timebase switch fingers not soldered completely?
Good Day,
I second Tom¡®s advice. Resoldering of the contacts shall be done only if really necessary and with great caution. It took me several attempts and sweat when I had to do it on similar Tek units,?
If really needed, use a good solder flux, a perfectly fitting solder iron tip and do it quickly to avoid neighboring contacts- as these can get misaligned very easily. Remove all residue when done.?
Cheers,
Magnus
You do not want to attempt to re-solder those contacts as it will
disturb the alignment of the contacts.
Regards
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On 3/7/2019 12:49 PM, bbortnick@... wrote: Hi all,
Now working on the cranky timebase rotary switch. After pulling out the timing board (not hard; skip step 2.c - remove 3 wire cable - as it's redundant with step 3 which removes the other end of the cable from the A TRIG HOLDOFF pot.)
Found the inner knob was off by 2 notches, so could not turn into x-y mode. Easy adjustment with the knob's grub screws.
However I see that a number of the fingers appear to not be soldered properly to the top of the board (see linked photo).
/g/TekScopes/album?id=86374
Should I re-solder all of these?
Thanks for the help!
|
Switches and contacts. If you have another vertical plugin, try it. The biggest issue witch these old scopes is dirt and patina on electrical contacts and switches, so: - Give plenty of workout to all controls (rock every knob back and forth many times) while observing the trace on a powered scope. Noisy contacts will clearly reveal themselves. - Check/clean the plug of the vertical plugin (both male and female part). - Re-seat the tubes. Check if tube pins show signs of corrosion. Visual inspection of the state of switches (corrosion, patina) could indicate if the whole instrument suffered from humidity and requires restoration of switches. This is recommended for such old instruments, but you may get away without that if the instrument was carefully preserved in dry environment. Nice scope though. Wish I had a 581/585 to restore... Best Regards, Nenad Filipovic On Fri, Mar 8, 2019 at 8:35 AM Rich Collins via Groups.Io <richanny= [email protected]> wrote:
My old 581a scope with 82 plug in hasn't been used for a year and when
switched on, there was no vertical response, just a horizontal trace. The
time base is working fine.The neon indicator is showing the trace is
up.I've never had to repair it in the 30 years I've owned it!I have the
service manuals. Any advice on what to check initially?
Rich
|
Re: Tektronix AM503S AC/DC Current Probe Amplifier system
If you need it done urgently and well, you should see about finding a cal
lab that still supports it.
Calibration requires the appropriate quality of signal generators, some
special adapters, and the GPIB board from an AM5030. I have most of the
kit, but not enough to do it right.
It also appears to be a somewhat intensive process: take measurements, fill
out a worksheet, measure % error in several ranges, then update the
constants over GPIB. If there's Tek software out there to automate things,
I haven't seen it.
Dave Casey
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On Fri, Mar 8, 2019 at 12:34 AM Mark Weimer <inxsof1@...> wrote: Hello all,
I have a Tek AM 503B in a TM502 mainframe.
Tektronix AM503S AC/DC Current Probe Amplifier system. The battery on the
plugin went dead and it seems to have lost all of its default calibration
coefficients.
Does anyone here know of a way or of a someone who could do a reload on
this plug and calibrate it.
Regards
Mark
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Re: More on TEK-Meter THM 565 Repair
Hi Jim! how are you? Pips here from New Zealand, lucky coincidence my wife used to live in Minneapolis for a couple of years she did an Au pair exchange many moons ago, and she of course remembers it very fondly.
I found this THM565 at the bottom drawer of the old manager of the company we run now, and I am experiencing similar faults to what you describe, in my case I'm trying it with batteries, I can clearly hear a beep and a relay contacting when pushing the ON button but no image on the screen, I been told that that was the main problem that's why they left it in that drawer. I could really use it because its very handy and would like to fix it, I'm an old electronics technician and audio engineer, but could use some guidance on what to check and how? from the manual it says that the screen could fade but they only say to take out the battery pack and re instate it. so to me sounds similar to the problems you have experienced.
Thank you very much
Cheers!
Pips
Gisborne
New Zealand
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My old 581a scope with 82 plug in hasn't been used for a year and when switched on, there was no vertical response, just a horizontal trace. The time base is working fine.The neon indicator is showing the trace is up.I've never had to repair it in the 30 years I've owned it!I have the service manuals. Any advice on what to check initially?
Rich
|
581a no vertical movement
This scope has a 82 plugin.The up neon trace finder is lit, but trace is horizontal flat in the middle. Time base fine.Any ideas welcome.
Rich
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Tektronix AM503S AC/DC Current Probe Amplifier system
Hello all,
I have a Tek AM 503B in a TM502 mainframe.
Tektronix AM503S AC/DC Current Probe Amplifier system. The battery on the
plugin went dead and it seems to have lost all of its default calibration
coefficients.
Does anyone here know of a way or of a someone who could do a reload on
this plug and calibrate it.
Regards
Mark
|
Re: 152-0310-00 replacement
I opened up the scope and the parts in question are small and completely gold in colour with two leads also gold in colour. I¡¯m not sure if I got all the writing but I managed to see ¡°0310GE¡± written on them. So, which ones do I have in my scope?
(I had tried to post this the other day but it doesn¡¯t seem to have made through. I apologize if it eventually does!)
|
Jean-Paul
David C. Partridge
Roberto
mrlepipi