[Boatanchors] Never seen this before

[Francesco Ledda]

Here it is a beautifully restored National FRR-59.  All clean, with checked
tubes, perfectly aligned.

Nice radio, nice sound... ten minutes later goes dead!.

Turned on again, and now, it works again.  Ten minutes later, it is dead
again.

Turned on again, and now, it works again.  Ten minutes later, it is dead
again.

Same story again fro three more times.............

Now, I'll find the problem....   Here it is a bad 5654.
Strange, I checked all of them, and now, this is totally dead.  How can a
perfectly working tube go bad in few hours?

Now, I know it was an intermittent filament!
Learning never stops!


Francesco Ledda
Texas, USA