Indeed, the Philips PCC88 datasheet appear to be somewhat inconsistent I found one that says 7.6 V, and two (incl. La Radiotechnique) that say 7 V. Anyway, 8.2 V is out of tolerances. Did you measure at the pins?
Best regards!
Best regards!
Close to the pins. the voltage drop in the wires between the pins and the test tips (socket, short wires) was surely not more than 0.1...0.2 V.
Well, then this specific tube isn't representative. But in a series string it really doesn't matter ;-).
Best regards!
Best regards!
Perhaps they were manufactured to the customers requirements in which the equipment had a different voltage supply. I have 2 lots of valves, 1 which have heaters which don't conform to the datasheet and the other that does. I found that by matching the heater to their required wattage yielded a glow that looked about correct and the measured curves were about the same after making the adjustment. I can't quite remember the difference in voltage but it was something like 4.2v instead of 6.3v
But they'd still need to match each other in that sting so that they are consuming about the same power.
... and apologies for digressing
That. The archetype was the E88CC/6922, which in about 1953 was found to be of much lower noise than the PCC84 that was used in European TV frontends before. To circumvent warranty issues, tube manufacturers developed the consumer quality PCC88 from the E88CC by providing another heater that required more power, for whatever reason.
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Not necessarily. As there were tubes of very different heater power requirements in the same heater string anyway, main criterion was matching warmup time.
Best regards!
Yesterday I was looking at XRK shop on this forum and he recomend the 6n1p over other 6922 types . 6n6p a good one . 6CG7 family as slow turn on and they last for ever. I like the Sylvania ones . The key is the circuit . A 6np1-ev sing at 250 v .
Sometimes there is nothing better than original ones as they were sorted between thousands.
Sometimes there is nothing better than original ones as they were sorted between thousands.
6N1P and 6922 aren't even comparable and even less interchangeable! The only Russian tube that corresponds to a 6922 etc. is the 6N23P or it's -EV variant, as yet mentioned.
Anyway, Matthias is looking for real Western originals.
Best regardas!
Anyway, Matthias is looking for real Western originals.
Best regardas!
With full documentation that is practically never delivered with tubes (not even with tubes for weapon/nuclear purposes). With bog standard RF tubes even less chance.
He didn't say that the manufacture had to provide it, just the seller which isn't that difficult to do in modern times now that products like the Utracer kit are available for reasonable money.
Buying a premium tube for a premium price, I would expect it to be tested and offered with returns accepted. I consider that to be reasonable, but sellers don't always see it that way.
I do agree that the OP will need to be a little bit lucky as I expect the cream of the crop would have been cherry picked long ago and used until they were worn out.
Buying a premium tube for a premium price, I would expect it to be tested and offered with returns accepted. I consider that to be reasonable, but sellers don't always see it that way.
I do agree that the OP will need to be a little bit lucky as I expect the cream of the crop would have been cherry picked long ago and used until they were worn out.
That!
Some of these tubes were made 60+ years ago, and it's very unlikely that anyone will know the full history of the ones that are still kicking around today. That's why it's always useful to have some measurements to assess the health of the parts. Attaching an "NOS" label to any old tube is a very common practice, but a measurement is so much more meaningful.
The PCC88 vs ECC88 question is interesting -- but let's not dilute this thread with the PCC88 heater question. I might take a good look and compare my PCC88 tubes to the ECC88 sometime and post the results in a dedicated thread.
Thanks everyone for your offers! I found what I needed, so please don't send any more offers to my PM inbox. 🙂