6 Burroughs/Ultronics B-7971 tubes for sale

[donf99]

All,

 

I have 6 assorted Burroughs/Ultronics B-7971 tubes for sale on Ebay:

 

http://www.ebay.com/itm/140902384188?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

 

The tubes have all been tested and all segments are working at equal brightness within each tube. I've tested each segment of each tube at the minimum recommended voltage of 170 VDC, and confirmed that each segment's current draw is within spec, using a 2.35 Kohm anode resistor.. The test data for each tube and segment is in the pictures section of the listing.

 

3 Tubes are labeled "Burroughs". One tube's markings have been rubbed off, but is likely a Burroughs tube. Two tubes are labelled "Ultronics". One Burroughs tube has the "antenna" wire present and is slightly taller than the other 5 tubes. One tube shows some darkening of the envelope and is slightly dimmer in appearance when lit, due to the envelope darkening. The tube pins have some slight darkening due to age.

All tubes have been completely tested. All segments are working at equal brightness within each tube and show no signs of "cathode poisoning" which can reduce the brightness of some segments.

I do not represent that these tubes will work in any specific circuit, only that all tubes and segments are operational at the manufacturer's minimum voltage and current ratings. It is up to you to insure that your application meets these requirements.

Absolutely no returns!

Please email me with any questions.