Ok a little (actually a lot) back story. I intend to use this resistor in my HP 1720A oscilloscope, therefore the lead spacing isn't important.
So I have this oscilloscope, and it has -unfortunately- an annoying intermittent problem, the trace sometimes jumping in vertical plane. Sometimes it is barely noticeable, sometimes it makes the scope practically unusable. The problem is very intermittent, there was a 1 year period for example without any problems, lately it does it almost everytime I use it. Sometimes it produces when it is cold, sometimes when it is hot. I already sprayed a can of freezing spray on it without getting closer to the core of the problem.
Below is a less severve capture of the problem:
I've spent A LOT of time chasing this problem and narrowed down pretty much as well, still it isn't solved.
This is the schematic of the Vertical output amplifier. U1, U2 are proprietary HP parts, they are nonexsistent on the market, both of them coupled to the heatsink.
-U1 was in a socket, but I soldered in to rule out contact problems.
-The whole board was resoldered multiple times.
-Supply voltages are stable.
-The problem even comes out when the input of the Y amp is shorted (therefore it isn't coming from the preamp stage).
-It is not the "BAL ADJ" pot.
-I suspect U1 and U2 are not defective, since the jumping isn't affecting signal shape, it looks like a simple (but hard to find) contact problem in the load (or balance) resistance.
-It might be the tube itself.
Now, there is the A5A1 board with work resistors for the Y output, also proprietary HP part, two thick film power resistors on an alumina substrate. Thick film is important because of it's induction less nature (note the scope has 275MHz bandwidth, and that frequency appears on this resistor at some 30V amplitude) -It gets HOT too!.
This is it (picture was taken when the center lead came off):
It is very fragile, especially the lead out pads (they come up when I try to solder them), the resistor's middle leg already was repaired, the plug you see at the end of the gray wire go directly to the tube, that plug also feel very unsecure on the tube (although I tried to press it, but still). So I can't replace the plug because of the aforementioned very fragile lead out pads, so I'll leave it just as is, and try to replace the whole resistor with new one.
So here comes this TA810PW resistor. The schematic says this resistor should be 2x165 Ohm, however in the actual machine I measure mine to be 2x154 Ohm pretty accurately, this 300Ohm version shouts for center taping, and even if the resistance is not precisely halved I still can trim the resistors with a sharp needle or whatever. it's size and design would just fit here fine and I'd try out this one as a probable solution without destroying the original part.
I really think at this point that the problem is either caused by this resistor or the tube itself. The tube is electrostatically deflected although it is signed as a yoke, and apparently has two leads on the tube for each plate, and between the two leads there is a resistance around 1 Ohm (definitely more than a short). As I read this was called as distributed line deflection and was a state of the art technology back in 1976 when this oscilloscope originally came out, so I hope it's not the tube...
