[TenTec] Blown Up Centurion

[David Propper]

Mike,

Big Bang is typically the HV filter caps.  Once you need to go in there, re-do the entire power supply, i.e.: diodes, filter caps, and THE BIAS TRANSISTOR ! I had the HV xfmr fail on me about 10 years ago.  Check for shorts across the windings, as you mentioned below, if you are reading 50 ohms from the secondary to ground, your xmfr is toast.  If you are reading the winding itself, 50 ohms, sounds ok. I’m not sure that1 megohm from the winding to ground is good.  I still have the old xfmr, so if you like, I can measure mine, but I won’t have a chance to dig it out until tomorrow.

10 years ago, TenTec was able to provide a new xfmr for approx $500 !!!!  Not sure if you can still get them from TT or perhaps  Peter Dahl.

By the way, the bias transistor failure symptom has been well documented on the TT reflector if you need more info on that.

Good luck, let me know what you are finding.

73,
Dave, K2DP


> On Sep 2, 2017, at 12:35 AM, Michael C. Marx <sndtubes at vacuumtubes.com> wrote:
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> 		Well I was using my Centurion tonight in the CW Open.  All was fine until ....BANG!  When I went to test it later, there was no plate voltage. I don't see anything obvious.  I pulled the tubas and still no plate voltage.  Testing the secondary of the power transformer showed 50 ohms across the secondary and 1 megohm plus from either end to ground. I haven't tested further.  Anybody have any suggestions?
> 73 Mike WB0SND 
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