[TenTec] Centurion loading

Ken Brown ken.d.brown at verizon.net
Tue Jun 21 00:05:27 EDT 2005


Hi Mike,

> Highest output 
>is still obtained with the Load control on 10. 
>
Most amplifiers do not have enough capacitance in their variable loading 
capacitor to operate much lower than on about 14 MHz. Fixed capacitors 
are switched in parallel for the lower bands. An air variable of high 
enough capacity to work on 160 or 80 meters, without paralleling some 
fixed capacitors, would be huge, and the amplifier cabinet would have to 
be much larger to accomodate it. My guess is that in your amplifier one 
of the fixed capacitors that should be paralleled with the variable 
loading capacitor has failed, become disconnected, or changed value, so 
that when you're on 80 meters, your pi-net really does not have enough 
loading capacitance. Could be a burned contact in the band switch or a 
loose screw terminal on a doorknob capacitor.

Disconnect all power and short the HV to ground before checking it out.

DE N6KB




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