[Hallicrafters] Testing tubes

[Roy Morgan]

At 03:03 PM 9/28/03 -0600, Barrie Smith wrote:
>I noticed that 6 of the 7 12AX7s tested off-scale (to the right, above 100).
>New 12AX7s that I tested ran from 80 to 90 on the scale.
>
>Is there a problem with an off-scale reading?

That's odd.. maybe they are actually 12AT7's not AX7's (I may be 
remembering the gain values wrong...)


>  Upon powering them up in the tester, the wires in the base that evidently
>connect to the cathode lit up bright red to almost white for a short period
>of time, perhaps a second or two.

This is typical of such tubes made in Europe, perhaps from Mullard or 
Seimens.. I don't know.. but don't worry about it.

Roy

- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
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