[Amps] Q meter [TSPA]

[G3rzp at aol.com]

In a tank circuit, rather than use a Q meter, I prefer to put a suitable  
resistor from the plate to ground (and with no HV, of course) feed a signal in  
from the output Then use a valve voltmeter to measure the RF volts that appear  
at the plate, while an SWR bridge in the feedline shows when the tank is  
correctly tuned. This enables you to check for choke resonances, and yet you  
don't hit the physical problems of trying to connect a Q meter - which is, after  
all, a pretty unwieldy beast physically to try to connect into an amp. You 
can  measure working Q by finding the 3dB points, too.
 
Incidentally, does anyone make Q meters anymore? Over the eyars, I've used  Q 
meters a lot at work, but I'm not convinced that they're something you can't  
do without - like grid dip meters - that's another thing you can get away  
without.
 
73
 
Peter G3RZP