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Big Valve!

PostPosted: Thu May 12, 2016 7:35 pm
by jskinner97
A friend of mine sent me a load of pictures of radios she and her dad have in their loft, she also sent me a picture of this massive valve on display in their house!

Whatcha' think it is? Im guessing TV Transmission Valve in the power circuit??

Says Thompson....
She adds
Apparently it was used for mri scans or normally operates submerged in a tank of oil for cooling and insulation.

Re: Big Valve!

PostPosted: Thu May 12, 2016 8:06 pm
by Marconi_MPT4
Could be this one manufactured by Thales!

Link points to an adobe pdf data sheet.

Heater power alone is roughly 130W with a peak cathode current of 5 Amps.


Re: Big Valve!

PostPosted: Sat May 14, 2016 10:10 am
by alanworland
Wow! What a beauty.
Used in Gulliver's Travels?


Re: Big Valve!

PostPosted: Sat May 14, 2016 4:50 pm
by crackle
Wow, hook it up to an industrial microwave transformer PSU and make a nice class A amp, and see if it will irradiate the neighbourhood.


Re: Big Valve!

PostPosted: Mon May 16, 2016 6:00 am
by Dr Wobble
Nice one Mike. ; ) pity she doesn't have a pair. Looks to be about a foot to 18" tall going by the CD rom case bottom right. What an amazing bit of engineering.


Re: Big Valve!

PostPosted: Wed May 18, 2016 8:52 pm
by Herald1360
I doubt that's been anywhere near an MRI scanner- from the datasheet it looks more like it was used to control the EHT supply to an X-ray tube, so a CT scanner would be more likely. TBH I don't think valves have ever featured in MRI scanners, even in the RF transmit role- by the time MRI was invented, solid state RF was well up to the job.

I doubt it would be any use at UHF either; it might do as an audio bottle, though it's rather large for its 1KW average anode dissipation rating compared with say four 4CX250s or a couple of 3-500Zs.

Re: Big Valve!

PostPosted: Thu May 19, 2016 8:38 pm
by cobaltblue
Yes in terms of anode dissipation it looks kinda small compared to my favored doorstop the the QY5-3000A

Used for 405 transmitters the 3 examples i still have came from Carradon in the early 1970's


Mike T