K3 - KAT3 C10 blew up!

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K3 - KAT3 C10 blew up!

J. Heide
After running a little Olivia on 80 meters last night at abour 40 watts, I switched over to my 6 meter repeater channel to call a friend. Upon keying on 6, I heard a little "pop" from the radio area. Didn't think too much of it, just thinking it was expansion of the case from transmitting (it's cold in the radio room.) This morning I was playing around with the new auto calibrate and noticed bad SWR on 15, 12, 10, and 6 meters with the tuner bypassed and transmitting into my IFR1900 service monitor. Power seemed low at the higher settings, but I thought it might be the power cable that is wee bit too small. Then there was a smell...Not the normal burned electronics smell, but a sweet, smokey smell. I decided to look inside and also to pull the synth to put in the 56k resistor per the new mod. Carrying the radio to the bench, it rattled. C10 on the tuner decided to blow up, so it's a call to the big E tomorrow for a replacement. Everything else looks fine
 except for some residue on the relays. I wonder why this happened. Radio ran fine on 80, and this happened the first keyup on 6 FM, using a memory channel for the 6 meter freq. I have run data at more power for longer times in the past with no problems.

And the KRX3 comes tomorrow....

Josh K6ZRX
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Re: K3 - KAT3 C10 blew up!

KF4VTT
Wow...This happened to me today on very similar circumstances.  I was warming up for the VHF contest and "POP".  I was having problems get the 6M beam to tune with a low SWR.  Strange...it was a perfect 1:1 on the antenna analyzer.  C10 finally burned open leaving the parallel inductor to complete the path to the antenna port.  When I get back to the states I will replace the capacitor and hope for the best.

73,
Doug KF4VTT/VP9