[R-390] re; R211

[Roy Morgan]

On Nov 7, 2009, at 6:51 PM, wli wrote:

> I am in the process of going through the RF deck on my 1952 Collins  
> R390A. The first thing that struck me was the chassis darkening in  
> the subcompartment under HR202. As we know the heater is *on* all  
> the time,

That heater is running all the time, but should not be engaged by the  
thermostat all the time.  It should cycle on and off.  A clever fellow  
would dope out the oven contacts, and/or devise a little indicator  
circuit to monitor that thing.  If the thermostat fails stuck on, the  
crystal will get too hot.  Most/all ovens of that size take 6 to 7  
watts of power, so at 6.3 volts an amp is running the heater when it's  
on.

I'd like a little LED to be nearby telling me if the thing is actually  
cyclling.

Roy


Roy Morgan
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Groton NY, 13073
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