This is a balanced single Philco 6X4 vacuum tube. This tube has a 7 pin tall glass bottle with Philco markings on the tube. It was made in the legendary Philco Lansdale factory before Sylvania purchased the factory. It tests very strong, with greater than NOS readings. This tube has black plates, clear glass, faded or yellow lettering, and square top getters. These are excellent Philco 6X4 tubes that are highly sought after, act quickly before they sell out!! More available upon request.
Be careful buying tubes from sellers who list tubes as matched if they do not provide test results or the equipment that they tested their tubes on.
I personally tested these tubes on my recently calibrated Hickok 600a and my TV7D/U and the results are as follows:
Pass/Pass
*Rectifiers test on a pass fail scale, they are not measured on gm or transconductance.
| Listed | a year ago |
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| Condition | Excellent (Used) Excellent items are almost entirely free from blemishes and other visual defects and have been played or used with the utmost care.Learn more |
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Product safety information may be available here.

