[Boatanchors] restored radio question

[Flowertime01 at wmconnect.com]

Gerry,

Nothing like a math problem with lots of variables.

Check the rubber your mileage may vary.
That's one variable.

The R390 Fellows while beating a horse to death found lots of old data from 
the prime days of tubes (before sand state).

Tube life is at least 5000 hours. Filament on off cycles is about 2500 cycles.

If you turn the radio on, then leave it on for at least 2 hours.

That's two variables.  

Electrolytic need two cycles a year, Four is better.

That a fourth variable.

Some of the other caps may leak with age.
These usally result in power hums or low output.
You likley eyeball these problems while inspecting the rubber parts.

That's a fifth variable.

So once every three months, inspect the rubber for cracking and play the 
radio for two hours.

That should keep each of your receivers running for 625 years on a new set of 
tubes.

With this in mind any one should be able to keep a good old receiver running 
for almost forever. 

Just eyeball it for the obvious mice nest and broken insulation, then operate 
it for four hours twice a year minimum. Four times a year preferred. And if 
you do it just once a year and leave the set on all day, the set should play 
until you pop a filament open at the time of power on.

Turn them on and enjoy them

Roger AI4NI

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