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Author Topic: AL-80B Watt meters  (Read 1445 times)
N9XTF
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Posts: 282




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« on: February 02, 2006, 11:55:06 AM »

I have lost the peak reading feature on my forward and reflected watt meters.  I had a HV short to ground awhile back.  The manual refers to D117 a 1N4001 diode as meter protection for the IG and IP meters that will blow under this condition.  Is there a similar protection device for the watt meters that will cause the loss of peak reading capability?

Thanks,

Doug - N9XTF
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W8JI
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« Reply #1 on: February 03, 2006, 07:24:22 PM »

There is an op-amp on the metering board. It almsot has to be something in that circuit. You'll have to trace it from the schematic. If the meter reads pretty close to normal but does not read peaks and if the pointer moves fast, I'd suspect the two 2N3904 transistors Q301 and Q302.

Almost has to be them.

73 Tom
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