[TenTec] Omni C -- It's Alive!

[denton sprague]

reminds me of having to tighten down all the nuts, bolts and screws in the final bricks of my old TT Delta and Paragon II rigs….heat from the finals and B+ connectors to the finals would cause the hardware to work a bit loose. 
I was running a lot of full bore out rtty in those days!

On Oct 22, 2013, at 8:37 AM, Paul Harker <paul.r.harker at gmail.com> wrote:

> Much thanks to all who contributed to the thread regarding my OMNI C. I'll
> save you the long and whining road of my internal torment, but I ended up
> going with a matched pair of Motorola MRF458s (same as original). I took
> the middle road between "it's not worth fixing" and "better than original
> parts".
> 
> Including a shipping and a pair of 3.3 ohm resistors to replace two which
> had developed a tan, the repair was just under $70 -- not including a much
> needed upgrade to my soldering station.
> 
> Final assembly and checkout revealed another problem, possibly what caused
> the meltdown in the first place. The 13.x volts to the PA goes to a
> pass-thru connector consisting of a nut, screw, insulators, and two
> star-washer type solder lugs, one on the inside an one on the outside.
> 
> The solder lug on the inside had developed a high resistance (hundreds of
> ohms) between itself and the pass-thru nut/bolt. This resulted in a low
> voltage to the finals, but proper voltage to the driver stage which has a
> separate power pass-thru. It wouldn't be hard to see how that could blow
> the finals.
> 
> I replaced the MRF458s without incident, cleaned up the 13.x VDC power feed
> through, and had previously found and replace a leaky sense diode in the
> SWR meter circuit. All seems back to normal, except for my frayed nerves
> whenever I turn up the DRIVE control.
> 
> Thanks again to all who contributed answers to my original thread!
> 
> Paul
> AC8OI
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