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Old 26th Jul 2017, 10:28 pm   #35
1100 man
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Join Date: Apr 2016
Location: Ventnor, Isle of Wight, & Great Dunmow, Essex, UK.
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Default Re: Kolster Brandes RV 10 (Crown)

Originally Posted by sexton_mallard View Post
I left the set on for 10 mins to see if the LOPT was getting warm but the PL81 was definitely 'red plating' so I switched off! The LOPT remained cool despite being grilled from the PL81..
All the current flowing through the PL81 will be flowing through the primary (between the two top caps). As this is only 10 ohms, the power will be quite small and probably won't generate much heat in 10 mins.
If the coupling cap from the anode of the line oscillator to the grid of the PL81 is leaky, the PL81 will certainly get hot and bothered- certainly worth changing.
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