[TenTec] tripped up... or down, as the case may be

[Jim Goudie]

Thanks, Jerry


On Jan 17, 2011, at 5:17 PM, Dr. Gerald N. Johnson wrote:

> 
> 
> On 1/17/2011 3:10 PM, Jim Goudie wrote:
>> Hello all,
>> 
>> A tale of misfortune and fortune.  And before I decide which way to go, I thought I'd check and see if the symptoms  ring any bells out there...
>> 
>> I was on the air with my Omni VI opt 3...  I was switching bands fairly often, and the last switch was to 160.  I set the tuner, which for 160 produced a rather sharp null.  When I keyed the rig, the breaker tripped.  That's odd, I thought.  I hadn't tripped the breaker like that in many, many moons.
>> 
>> Shortening the story, after resetting the breaker, I found it would trip as soon as the output power got up over a watt or two....  And it did it on 80 meters... and 20 meters without the tuner in line.  I shut down for the night.  Today, going into a dummy load, it put out power until about 50 watts out, and then the needle on the power meter went erratic, but the breaker never tripped.
>> 
>> The side story&  symptom are that last night, after fooling around, I realized the rig wasn't receiving any signals.  This morning, when I first turned it on, it received ok.  But, after doing my dummy load testing, the received signals were gone again.
>> 
>> So... I pulled my trusty 544 off the shelf to replace the Omni VI at my operating position... and operated for three hours with that.
>> 
>> I'm guessing the problem lies in the SWR-sensing, tx-rx switching stuff in the output...  I haven't cracked it open or even looked at the schematic yet...  Any thoughts?
>> 
> I think that's the first place to look but be sure all the board grounds 
> are tight so that the PA or RF board isn't oscillation at some out of 
> band frequency.
> 
> I recall losing the diodes in the SWR sensing/ALC detect area has made 
> several TT radios do weird thiings.
> 
> 73, Jerry, K0CQ
> 
>> Jim, AF3Z
>> _______________________________________________
>> 
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