In an attempt to establish base drive levels from the Oll to drive the
Centurion Amp to 500 and 1000 watts I discovered that the out put of the Oll is
more than the indicated pwr out on the display. For instance 100w on the
display was actually 116 w out through and Bird wattmeter with a newly
calibrated slug from Bird. From the Bird I went to a 50 ohm dummy load with its
own pwr meter built in. Military TS1771/u. With 80 w indicated on the display,
the actual pwr out was 100 as measured with both meters.
I did find on the TT Wiki a procedure for adjusting the pwr output. It is on
the A9 board under the speaker. R179
This gave me cause to check the Oll SWR calibration against a known load. As
suspected the internal SWR meter is off. I checked the SWR through my 238B
antenna tuner and my old Heathkit HM-11 and also through the bird. With 100
watts forward there was 6w reflected which is 1.6 to 1. All of these meters are
quite close. The Oll meter showed 1.9/2.0 to 1. Sometimes the auto tuner would
not tune, so I suspect that the SWR bridge in the Oll needs calibrated.There
are adjustments on the A5 board for fwd and reflected pwr. R20 &R21.
I have not been able to find a procedure to do that. Anyone have information????
Andy, W3LI
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