For less than ~$100 in parts you can build your own. For example see the last page of https://www.digikey.com/htmldatasheets/production/80467/0/0/1/ltc2485-datasheet.html. The ltc2485 is a 24 bit ADC

Good catch. I now note that the 535 which is offered is Grey, not blue, and has square corners. The lower left corner of the photo in question shows blue and a rounded corner case. Sure glad I did not

https://detroit.craigslist.org/wyn/msg/d/livonia-tektronix-535-vintage-tube/7271634106.html

With regard to left hand drill bits, at the Ohio State Imaging Sciences Lab our motto was, when it comes to mechanicals: "If McMaster doesn't have it, you don't need it". https://www.mcmaster.com/ Kee

Thanks Dave, as far as I can tell all the 7904 manuals on the TekWiki are for s/n b260000 and up.

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

My 561 has a bad HV XFMR, will cryo tubes and special audio cables fix that?

Sorry, that's 7904 not 7004

#photo-notice

I'm rewinding the HV XFMR in my 561 but would not mind a backup plan. How is the T600 in yours? As an aside, does yours have a 4.3 Ohm resister in series with the 1 turn secondary for the filament of

Use a "BNC Wrench" to hold or tighten the BNC connector. There are many different ones available or you can make your own..just a hole and a slot. Here is one that looks well made but a bit pricey. I

Hear! Hear!

Data sheet: https://www.tek.com/datasheet/active-power-rail-probes Interesting, but U$4300.00 for the cheap one. Accessories are extra.

Perhaps to control reflected light. Reflected light goes through the filter twice while light from the phosphor once.

See http://w140.com/smb/DC508A_SM.pdf page 1-1.

( I sent this some time ago but I think I only sent it to myself, I'll try again) When I was servicing TV's (mid 60's!) we carried, in our tube caddy, tiny auto-transformers that would, for most BW tu

When I was servicing TV's (mid 60's!) we carried, in our tube caddy tiny auto-transformers that would, for most BW tubes plug inline with the socket and boost the heater voltage by a volt or so. For C

Just as an op-amp (with negative feedback) nulls the voltage between the inverting and non-inverting inputs here the nulling is done with wetware and the center zero meter.

I the corrosion/staining shown in the photos below a known problem? Can it be cleaned or has the finish been eaten? It is CL about an hour away and I'd like to know what to look for. thanks [cid:part1

Thanks to John, Bert Trevor Dennis, David, and John H for your informative and insightful comments on the 7613 and the 7603. I've got my fingers crossed for a ham-fest on the 19th. cheers

Hi Bert, After reading the comments about the 7613 I have to agree that the 7603 is a better deal. Good luck selling your 7623 cheers