This vacuum tube has only been tested on my B&K DYNA JET 606 TUBE TESTER

(I can not check for transconductance)

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The B&K is newly refurbished and calibrated to the original factory specifications.

The DYNA JET 606 is a very reliable emissions tester that can automatically check for shorts and leakage to approximately one megohm.

Grid emissions, gas, grid contamination, or obscure grid to cathode leakage are all disclosed by an exceptionally sensitive grid current check.

Each tube is checked for quality in a test circuit that determines the full capability of cathode emission under current loads simulating actual operating conditions.

After letting the tube warm up for over 10 minutes, it is tested for shorts, grid emissions, and then placed under load for around 4 seconds to check the quality.

The 1952 SYLVANIA JAN CHS 7N7 quality tested very high at 91%-92% and has no shorts or emissions leakage.

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This tube is SOLD AS IS with no returns accepted.

The utmost care will be used in packaging the product to ensure the same quality will be delivered to the purchaser.

Orders will be shipped during weekdays, when permitted, with Free Shipping Using the USPS.

Thanks for looking!