For sale U22 single diode EHT rectifier valves / vacuum tubes by Ediswan Mazda, new in original box and recently fully tested and working at 100% of nominal new emission.

Originally designed for early small black and white TV service, the U22 rectified the high voltage EHT to drive the cathode ray tube anode. It has a 2 volt 2 amp heater and can deliver 1mA EHT current at up to 5,200 volts. Be warned the U22 is on a MAZDA Octal base (not the same as a standard international octal base) so you will need one of these (or equipment that already has them) before you can use this valve.

It was first introduced in 1939 for the start of public television service, which was quickly withdrawn on the start of WWII. Throughout the war, the U22 was then used in various items of early radar and test equipment, so it gained no less than three services CV numbers, before returning to its original purpose from 1945 onwards.  

Nowadays the U22 is an ideal purchase if you have an early vintage TV set, such as a Murphy, that uses one of these, or it is an interesting valve for general high voltage experimentation (be careful!)

Fully tested on my Mullard High Speed Valve Tester and showing zero faults and 100% of nominal new emission. A reasonable price for this fully working, new in box example of an interesting old valve/tube. Ideal for vintage TV set restorers, experimenters, collectors alike.

U22

Heater = 2V @ 2A

Diode:
Anode / Plate:  5200V / 1mA max continuous

I offer a full, money back guarantee if you are not completely satisfied with this purchase (see terms). We have been trading since 1927 so bid with confidence. Most of our valves / tubes have been in our own stock room for many, many years. See our EXCELLENT FEEDBACK on quality valves / tubes previously supplied!

We have thousands of valves / tubes in stock - standard and rare; US, UK and European. If you have any particular requirements, please send a message and if we have what you want, we will list it here.

We ship worldwide and are very happy to combine items for multiple postage.

TERMS

GUARANTEE: In case of dissatisfaction, buyer must return item at own expense. We will only refund if you return the EXACT SAME VALVE / TUBE to us that you have purchased, with the heater still intact and passing continuity test. Believe it or not, some evil people have tried to send us back their dud tubes to try and get a full refund for a perfectly good tube we have just sold them! So, refund is a genuine offer, but at our discretion that we have been sent back what we actually sold you in the first place and that you haven't destroyed it through misuse! All returns under guarantee are limited to within 21 days of shipping.

PAYMENT: We accept all normal eBay payment methods. We are happy for you to collect from Bristol BY APPOINTMENT ONLY, but will require payment in GBP CASH on collection.