Not sure whether the amp is in CW or SSB position. If CW, that plate voltage looks a little too high; if it is SSB, it is 600 volts too low. Then again, most people don't check the accuracy of the internal voltmeter so they don't know the actual voltage accurately.
Might be worth a peek through the vent holes on the bottom or the fan on the rear to see if both tubes have their filaments lit. Too, one of the tubes, or both, could also be bad/soft. The plate blocking capacitor should be measured. Visual inspection of RF chokes for grounding the grids on both tubes should be inspected for heating or open circuit. 73, Evan, K9SQG -----Original Message----- From: Curt Nixon <[email protected]> To: drakelist <[email protected]> Sent: Fri, Jan 4, 2013 12:34 pm Subject: Re: [Drakelist] Drake L7E Low Power Out Can he use a different wattmeter/and dummyload link? At that kind of DC loading, something has to be getting REAL hot if it aint going into the dummy load. Is the plate voltage staying up with key down? Also, you might try testing with each tube individually to see if a tube got shorted in transit. FWIW Curt KU8L On 1/4/2013 12:01 PM, Richard Emrich wrote: I sold my L7 to another ham and he has sent me the following. I see very low RF output. Here are some numbers: plate volts 1900 idle plate current 180ma 30 watts input RF 60 watts output to 50 ohm resistive load (dummy load) plate current 440ma grid current 120ma I see little or no dip in plate current with plate control - all bands same effect. I checked the tube hardware, cleaned the output relay etc., there is no arcing, popping or gassy look on the tubes. The tube plates do show color on key down...I did let them warm up for several hours. I have gotten more output by increasing the drive but not over 160 watts out...don't want to hurt anything by pushing it. Any help would be appreciated Have a good new year Thanks NN6U _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
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