Fascinating diagnosis, Bruce. You give us another hard-to-spot failure mode to be alert to. It brings home the most basic test of any component, "Does it work in the circuit?". Dave Wise

Bruce, what a delight to see a reference to condensers. Cheers, John Ferguson, AI4TO

I was doing some cleaning up in my shop and came across something from a Tektronix 454 scope that resonates with this transformer discussion. I think "contaminated" epoxy may have caused another

I may be mistaken here, but from what I understand, the problem with getting them scanned and in pdf format isn’t necessarily the funds, it’s getting the manpower to get it done. Of course they

What is option 4Z? I have a 2465 that back plate indicates present. Thank you, Don

Some various oldies for sale..... https://portland.craigslist.org/search/sss?query=tektronix&excats=137-8-1-39&sort=rel

I DO NOT have a dog  in this fight but seems to me that those who "contributed" last year when the museum was soliciting donations for a Fiche scanner should have first dibs on setting prioritizes on

Chuck, My apologies also, We got started off on the wrong foot, Can we Please forget all that and put it behind us!I do appreciate your help very much! I have this Supply now and am commited to fixing

Following the discussion of the offer of the big microfiche library from England, and the indication that the Museum already has a similar collection and is willing to scan specific materials on

I would love to have it!

great,the owner just told me I was not the first to inquire about it. i was actually interested if the delay sweep switch is same as in 464.So if in you ar planning to take it apart keep me in mind.

Dan, I'll take it!  We can do PayPal as we have done in the past.  Let me know.  Michael Lynch 479-226-0126 Home Phone479-477-1115 Cell

I am getting this scope - will pick up later in the week or over the weekend. I don't need it but would like to find it a good home. I would ship from 78732 for actual shipping cost (plus the $20

Good point Morris. There are ways to tell if the hv is failing on the one beam side. You can turn out the lights in the room and check the hv rectifiers for the familiar red glow. If the hv has failed

AFAIK the 555 does not have the HV transformer thermal runaway problem that plagues later models. One other component that sometimes causes these symptoms is the 1 nf resonating capacitor across the

Maybe I should just make my own boat-anchor and weld two of my 2 545's together. I would have a nice huge 4 trace 30 MHz oscilloscope, redundant power supplies and Dual CRT's and almost 200

Hi Chuck, Thank you for the tip -- indeed that's all it was, and I was able to remove it after some coercion. Unfortunately in messing with stuff, I also loosened the internal switch cog that

https://portland.craigslist.org/wsc/ele/d/banks-tektronix-7704-oscilloscopes/6968559065.html

Yes I think you are right, John. I don't want to get carried away. It is sometimes difficult coping with an addiction like this. :-)

Yes, I do think the 565 is a wonderful scope. I have one of those. It only goes up to 10 MHz whereas the 556 goes up to 50 MHz, which is where I foresee the part of the spectrum I would be working in