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Re: Troubleshoot TEK 465
Seems like an unblanking issue.? Trace the signal that is supposed to raise the CRT control grid potential during sweep.? Sweep gate.
By Bob Albert <bob91343@...> · #175991 ·
Troubleshoot TEK 465
I am trying to repair a TEK 465 oscilloscope that my friend bought from ebay. It does not have a trace unless I push the Beam Finder button. A trace then appears that I can move vertically,
By wes Bolin · #175990 ·
Re: Peter Keller's Book Mailing Status (Minor Correction)
I don't dispute the issues you are experiencing with mail delivery but it is not like this . Dennis Not that it matters but my latest Media Mail experience is I shipped a book to Southern California
By Craig Cramb · #175989 ·
Re: Intermittent power on problems with 2465B
Histrionics, I love it! You must live in an alternate universe from the rest of us. I would rank electrolytic capacitors as being the second least reliable part in modern electronics, narrowly being
By Chuck Harris <cfharris@...> · #175988 ·
Re: Tek 7904 In Pulse Mode Related to C1511 on LV Regulator
I haven't looked at the schematic, so I can only speak in general terms. If that cap is indeed part of a loop compensator, I think it's ill advised to go about modifying it in any ad hoc way. Whether
By Tom Lee · #175987 ·
Early 7904, no readout
My new (to me) s/n B041515 7904 arrived DOA. (ebay, "not working, for parts".) With the help of my mostly trusty DSO138 I found the shorted 47/25V dipped tantalum on the -15 supply. Replaced it with a
By Bruce Atwood · #175986 ·
Re: Intermittent power on problems with 2465B
Let's see your stats for Tektronix equipment. I have never seen tants from Tek gear eject into ceiling tiles. I reject any dogma that is uninformed by relevant data. -- Prof. Thomas H. Lee Allen Ctr.,
By Tom Lee · #175985 ·
Re: Intermittent power on problems with 2465B
Re. recapping 2465B Youre on the cusp of learning the *hard way* why advice to NOT replace caps is extremely bad. Out of the multiples of semi load after semi load of equipment I worked on "back in
By David Campbell <k_8_b_y_p@...> · #175984 ·
Tek 7904 In Pulse Mode Related to C1511 on LV Regulator
Hey Guys, I'm in the process of (mostly done I think) repairing a 7904 power supply that goes into pulse mode. I replaced a number of the bad tantalums on the cap rectifier board which brought some
By rgpierce1@... · #175983 ·
Re: Peter Keller's Book Mailing Status (Minor Correction)
I don't dispute the issues you are experiencing with mail delivery but it is not like this everywhere. I mailed the books on Saturday morning. Monday afternoon I received an email from a member that
By Dennis Tillman W7pF · #175982 ·
Re: Quick question 564B
I have seen tektronix ferrite transformers broken for epoxy stress https://antiqueradios.com/forums/viewtopic.php?f=8&t=259178&start=20 -----Mensaje original----- De: [email protected]
By Miguel Work · #175981 ·
Re: Intermittent power on problems with 2465B
To Chuck, perfect advise as always. A few notes please: 1/ PSU fail to turn on is likely NOT solved by a recap of the PSU. Caps failure are rare but ESR goes up and C down as the electrolyte dries
By Jean-Paul · #175980 ·
Re: Quick question 564B
I don't like to assume anything. When they fail, worry about them. Some go on forever, it seems. Any of the transformers that use the brown epoxy are likely to fail at some point. It doesn't seem to
By Chuck Harris <cfharris@...> · #175979 ·
Re: Intermittent power on problems with 2465B
I recommend that you leave the A1 board alone. It is very difficult to remove without damaging something, and the capacitors on the A1 board are rarely bad. I would say never bad, but I am sure
By Chuck Harris <cfharris@...> · #175978 ·
Re: 7613 Mainframe - Readout problem
Yes, thank you, thank you, thank you. I just finished reassembling the 7613 mainframe, after replacing the U214 chip (155-0022-00) on the vertical interface board. The board can be accessed from the
By Attilio · #175977 ·
Re: Quick question 564B
Hello Chuck, My RM565 does have the aluminum can, but so far, it has been working like a champ so far. I am assuming that this will eventually fail. I do hope that it will hold out. But both of my
By Brenda <brendda75@...> · #175976 ·
Re: Intermittent power on problems with 2465B
Chuck, Thanks for the advice! Saw your earlier work on getting the 2018 cap list up dated. Thank you for that work too! I am going to give the re-cap a try (love the dead fish analogy on those SMD
By Mark Hatch <mark2382@...> · #175975 ·
Re: Slightly OT: How can I dissolve Potting Compound?
Dennis, You might take a look at "Attack Epoxy Solvent" https://www.gesswein.com/p-5097-attack-epoxy-solvent.aspx I used something like "Attack Epoxy Solvent" from Varian Associates in the late 1960's
By George Kerber · #175974 ·
Re: Intermittent power on problems with 2465B
On SMD caps: Take the cover off of your scope. Set it on the bench CRT side of the chassis down, A5 board up. Find the 4 SMD caps, and look at the solder joints that hold them to the circuit board.
By Chuck Harris <cfharris@...> · #175973 ·
Re: Intermittent power on problems with 2465B
I was hoping not to have to recap.... But it sounds like that is where this is going. I will just order the A5 SMD caps to have on hand when I dig through it instead of waiting for another order thru
By Mark Hatch <mark2382@...> · #175972 ·