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Old January 20th 04, 02:47 AM
Edward Knobloch
 
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In order to neutralize, you must first open the screen voltage
supply to the 6146's. This may require unsoldering the screen
grid supply at the 6146 sockets (pin 3 of each 6146 octal socket).
Leave the the tubes in their sockets, with plate
connectors attached. On the 10m band, feed some power to the grids
of the finals, and measure the output signal on the coax (50 Ohm load).
You can use a separate, loosely coupled receiver tuned to the frequency
for this purpose. (I.e., use a short antenna wire placed near
the output coax, connected to the separate receiver.)

Adjust the grid tune, plate tune and plate load capacitors
for maximum output signal, then adjust the neutralization capacitor
for minimum signal. There should be a point of the neutralization
adjustment where the output signal has a definite minimum.
Congratulations - you are now neutralized.

Be careful - you are working near lethal voltages, and you should use a
insulated, non-metalic tool to adjust the neutralization capacitor.

Keep one hand in your pocket when you reach into the transceiver,
so you won't get high voltage across your chest. If you don't +know+
what you are doing, ask another ham to help. Don't be alone
in the house when you are reaching around the 800VDC.

Both final tubes should be the same type. It is not good practice
to mix a 6146 or 6146A and a 6146B.

73,
Ed Knobloch

gil wrote:

Just recently got a Yaesu ft-101e that needed some alignment and the only
thing I cant seem to get "accurate" is the neutralization, the best I can do
is to rotate the adjustable plate capacitor till I get the lowest output
reading on the power meter, which range from 50 to 80 watts depending on the
band and it seems to put out a clean signal this way.
Trying to get a higher output reading only sends the finals into oscillation
with lots of hum and a somewhat "dirty" signal.
Am I on the right trak here or should I do something different?
Any info appreciated....thanks

Gil n2wjw