It would be fine with me if any extra went to the Tek museum. Bob

so Dennis, did you get mine, I used the address after changing the spaces and changed the at to @. Bob

Dennis, When I enter @Dennis_Tillman_W7PF (copied from your note), I get an error saying please enter valid email, name or mobile phone m=number. Bob

Fans in scopes seem to be fairly weak compared to other fans. For example kitchen exhaust fans, house fans etc. Try blowing through a regular house filter and you can see how restrictive they are. One

Craig, Thank you for all your posts and the many times you have helped me. Bob

Received and installed a new Thermister and 15Ohm resistor. The fan does start up better but there is still a problem. Watching it carefully, I see that the fan shaft has about 1/32 inch forward and b

The Mobil 1 5W30 sounds good. Also, I ordered replacement parts which are scheduled to arrive later next week. It will be interesting to see how adding back in the thermistor makes in fan startup. Bob

This is what I have https://www.liquidwrench.com/product/silicone-spray/ Model M914

Chuck, What oil do you recommend? I would like to try some. Bob

A careful check shows only the other resisters. Does anyone know the operating parameter of this part (1D1618, tek 307-124-00) ?

Chuck, yes Silicone Oil. Late evening typing has its risks. As to why that product, years ago I wanted to fix some sleeve bearing house fans. After some research, tried Silicone oil which has worked f

Wu Who! (yeah). Success, C8064 was bad. I only had 10uf 50V, but it worked. Started right away. One note. I tried it several times and found I need to wait 20-30 seconds or it doesn't start. But if I

Ah, Interesting, thank you for the reply. Had not thought of that. Unfortunately that doesn't sound fixable (at least not by Me). Looks like some kind of replacement. In researching 465B fans, Walter

Trying to get the fan in a 465B working. Initially I noticed the PCB under the IC was dark brown as if the IC had overheated. So I replaced both the IC and the transistor, just in case. Also, the fan

Strange, my 7904 does not show that kind of flare at normal settings. Initially I did have to fix the HV supply. I also changed out some DC restorer diodes that were leaky. Its been working fine ever

Unfortunately I already have a 465 and this is two hours from where I live...but if it were closer, well, https://sfbay.craigslist.org/sby/ele/d/san-jose-hp-oscilloscope-465/6985927239.html

I may have the NVRAM with internal battery as SN B013872, so I may try the grind and CR2032 trick. Or, could I add a larger battery like a 18650 (3.7 V fully charged) wired to each chip? Bob

Thanks, that simplifies the replacement ( and price) Bob

The 2440 manual lists the lithium backup battery as primary. As was pointed out elsewhere a primary battery is not rechargeable. So does the 2440 lithium backup battery need to be rechargeable and thi

Might be helpful, a 1978 transistor reference manual https://ia600607.us.archive.org/34/items/NationalSemiconductorDiscreteDatabook1978/NatSemiDiscreteDatabook1978.pdf