04-07-2015, 12:35 PM
An ordinary analogue meter will load the AGC line (obviously) but how much it loads depends on where the connection is made.
AGC diode loads can vary quite a bit depending on the circuit design, eg: a megohm or greater down to 200k or less.
The point I was trying to make is that for myself and lot's of other folks it is easier to interpret a moving needle against a background scale as opposed to a purely numerical and sometimes erroneous representation with a digital voltmeter display in the context of obtaining a peak reading when adjusting tuned circuits etc.
Using an analogue meter was/is a quick way to establish if the local oscillator is working in a valve receiver although in most cases the impedance of the oscillators grid circuit will less than what's typical in an AGC line.
If I had one I would use a valve voltmeter.
But hey ho each to their own.
Lawrence.
AGC diode loads can vary quite a bit depending on the circuit design, eg: a megohm or greater down to 200k or less.
The point I was trying to make is that for myself and lot's of other folks it is easier to interpret a moving needle against a background scale as opposed to a purely numerical and sometimes erroneous representation with a digital voltmeter display in the context of obtaining a peak reading when adjusting tuned circuits etc.
Using an analogue meter was/is a quick way to establish if the local oscillator is working in a valve receiver although in most cases the impedance of the oscillators grid circuit will less than what's typical in an AGC line.
If I had one I would use a valve voltmeter.
But hey ho each to their own.
Lawrence.
