I shorted it right at the B+ and the supply caps, bleeders, etc are not near
the point of the smoke puff which was around the tube sockets. I guess I
should power it up, use a lighbulb current limiter and see what happens? tnx
john
> Date: Tue, 9 Apr 2013 21:03:46 -0700
> From: k2vco.vic@gmail.com
> To: amps@contesting.com
> Subject: Re: [Amps] Basic Question Finding Passive Component Up in Smoke
>
> Well, if you grounded the B+ on the plate side of the RF choke, you could
> have heated the
> choke enough to make smoke without burning it out. It would probably be
> discolored in that
> case.
>
> Where did you ground the B+ and what was between that point and the power
> supply?
>
> On 4/9/2013 8:41 PM, john starr001 wrote:
> > I am a beginner learning amplifier basics and decided to build a simple
> > 6146 class C final CW rig with a 6CL6 driven crystal oscillator much like
> > the Eico 720 or Globe Scout. The power supply is a full bridge 600v B+ and
> > 300v non-regulated screen supply. I did something stupid and accidentally
> > grounded the B+ supply. So I blew the 3A AC line fuse but just before one
> > of the components in the 6CL6 or 6146 circuitry went up in a cloud of
> > smoke. I have visualized every cap, resistor and inductor and find no
> > damage. I have measured every resistor, directly or indirectly, in-circuit
> > and all are to spec. No open inductors and no shorted ceramic caps (all in
> > -circuit). I tested the power supply disconnected from the RF circuit and
> > the supply, without load seems fine. The 6146 and 6CL6 test fine as well.
> > I want to put it all back together again and test the voltages with the
> > 6146 and 6CL6 removed but I am a chicken worrying about blowing up
> > something else (like my transfom
er
> t
> > he next time). There was a obvious puff of smoke so something was lost.
> > I figure approaching this kind of problem must be routine for you guys
> > working on amps so would appreciate learning what would be your next steps
> > to find the bad part while minimizing further damage. I thought the 6146
> > screen would burn up if the plate B+ were suddenly lost but it tests fine
> > on my Hickock. tnx and 73john
> > _______________________________________________
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> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
>
> --
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco/
>
>
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