Collectible RCA Red 5693.   The Special RCA Red tubes were developed circa 1948 to support the growing need for low noise tubes.  They were advertised as "The 10,000 hour line" and employed tungsten filaments, extra mica, extra support rods all in effort to make a dead silent tube.  This tube will operate in any circuit that calls for a 6SJ7.

PLEASE NOTE: I have more of these in stock

TUBE TESTING NOTES:This tube was allowed to warm up for 10 minutes prior to taking GM measurements.  Tube was also tested for shorts/leakage, gas and mutual conductance.

No shorts, leakage or gas were found. GM measures 70 micromhos where 40 is the minimum for replacement.  Tests were completed on a calibrated Hickok TV7 .

Please note : small evidence or moisture/rust on the base

This Tube will be shipped in a new box and insured via USPS.  The cost of this is added into the shipping cost.

International buyers are welcome to bid but must have perfect eBay feedback, more than 40 ebay completed transactions and ship via the Ebay global shipping program. I only ship to US Domestic Addresses , so please use an international forwarding service.