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OP was looking for a more available part - not a jelly bean part, whatever that is. If the original is still available, why the subs? And no, most of us buy our parts in onesie-twosie fashion. What

Under $2 is not cheap for a jelly bean part. 2N3904 transistors are like 3.4 cents each. Even an MPSH11 which is a closer match to the 2N918 can be had for 8 cents each. Note that the above prices are

For those interested in the fixes I found for my 2247A where channel A sweep would not visibly function and the unit would not work at all? ????? What I found was two pins bent under on two

Thanks for the replies. I picked up two of these at the same time. Both work but both had transistors removed. I was looking for what were the most available parts for me that would work. Thanks for

Er, make that "two" places, and that doesn't include evilbay.... Cheers, Taylor Why all the subs? 2n918's are still very available, and at least tow places have them under $2 each. Hard to rationalize

Why all the subs?? 2n918's are still very available, and at least tow places have them under $2 each.?? Hard to rationalize subbing an available, cheapo transistor. ? Cheers, Taylor

No, not really. The 2N2222 has a higher power rating than the others and the 2N4401 has a higher current rating than the 2N3904 but none of that will matter in this application. As far as performance,

I don't know shy this has not been mentioned but the 475M is the same as the 475A with some mechanical differences. If you want to compare the 475M to the 475, use the 475A. This is quoted from the

That was my typo on the 2N918. Of the 3 you list is one offer any better performance? 2N2222, 2N3904, and 2N4401 Thanks

It is 2N918 and not 2N198. The 2N918 was a very common early VHF transistor. My 184 has 2N3605 transistors as well. The 2N918 is: 900 MHz @ 4 mA 30 Vcbo 15 Vceo 50 mA From the Tektronix parts book the

Thanks Victor, the heat sink is actually electrically isolated. It also has just enough clearance that you would really have to do some damage to the scope in order to get it to impact. Good piece of

Doubtful it's heat related. The chip runs at ~117F with no heatsink, that's pretty low. Search for U800 you'll find hundreds if not a thousand posts on the subject. Be careful with how large a

The problem is that the transformer is very fragile and is almost invariably the broken part. It is also unrepairable. Spare transformers, if they are good, could in theory help revive a "for parts"

I have been asked about price several times. I am asking $650 for the 495P and $500 for the TR503. The screen discoloration is not burn in. It is really not an issue, but I want to want it out ahead

Is all of this heat related? One of the first things I did when getting my 2465BDM was strap a very large heat sink to the U800 chip with good quality thermal compound and very secure mounting. It's

Now that I think about that is the 2N198 missing a digit? They are all listed in the SM as 2N198, semms like the last digit is missing?

I have another transistor question on this one. The unit is up and running as stated and looks to be within specs. I was checking the rest of the transistors on the countdown board and their are quit

Hi Chip, That was me! I do remember because you were very nice with the refund even though I had left Pos FB already. Not many would do that. I have seen three main failure modes on U800: 1. The trace

You can often pick up a "for parts" P6042 for the price he is asking for just the sensor. The only problem with that approach is that you might end up with a few P6042s and no time to fix them...

So, with the help of the folks here and some troubleshooting, I've gotten my 475 closer to being usable again. However, I'm stuck at a new spot now. I am getting almost perfect voltages at each test