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Old 28th Apr 2006, 1:59 pm   #15
steve1811uk
Retired Dormant Member
 
Join Date: Mar 2006
Location: Manchester
Posts: 33
Default Re: Roberts R200 LW reception poor

Phil, It sounds like the local oscillator is not running on LW when the battery is getting low. This could be normal behaviour as there is more capacitance added to the oscillator in LW mode and I think this makes it harder to oscillate. As the battery voltage is reduced the base voltage and hence emitter voltage are reduced. This leads to a reduction in emitter current that could cause the oscillator to stop. It could also be due to leaky capacitors at the base or emitter of the oscillator transistor. I will see how my Roberts behaves when the battery goes low but that could be a while. Why not measure the battery voltage, base and emitter voltages with the radio switched on when the LW stops and post that info here. Steve.
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