Maybe you can find a few boats in need of anchors. When I was repairing
K3ZO's Titans, I had two that had bad transformers. According to my notes
it was one of the 120V primary windings shorted to the 1010V secondary.
It is most likely the transformer. I'll poke around a bit more to see if I
can somehow confirm it.
73
Ken K4ZW
On Fri, Jun 6, 2025 at 5:49 PM gudguyham@aol.com <gudguyham@aol.com> wrote:
> I have a rack full of blown transformers from those amps. The usual short
> I’ve seen several times is one 120v primary winding shorts out. It’s been
> a while but sometimes they have an impedance short to the case. Often
> times it takes out one leg of the bridge. Turn on the transformer and
> probe all wires to ground on 1000v AC scale.
>
>
> Sent from the all new AOL app for iOS
> <https://apps.apple.com/us/app/aol-news-email-weather-video/id646100661>
>
> On Friday, June 6, 2025, 4:56 PM, Ken Claerbout <kenk4zw@gmail.com> wrote:
>
> I've been trying to repair a Ten Tec Titan Model 425 amp and I'm about out
> of ideas. Here's where I'm at.
>
> The Soft Start 1.5 amp fuse blows.
>
> This model power supply has the separate rectifier and filter board,
> mounted on top. The soft-start and bias circuitry are on the lower board.
> With the rectifier/filter board disconnected, the fuse does not blow. I
> have the gray cable connected between the PS and RF deck but not the HV
> cable. Anytime I connect the rectifier/filter board the soft start fuse
> blows instantly. Seems simple enough. Most likely something on that
> board, bad cap, diode, the usual suspects. Nope! Everything checked OK.
> But NR4M had new caps from a project he did so I "borrowed" eight of those
> and replaced the caps. Still blows. Replaced diodes and resistors. Same
> thing, fuse blows. Everything on the board has been replaced at
> this point. I don't see any burned traces on the board, like what happens
> sometimes.
>
> I pulled the lower board and looked it over. I don't see anything wrong
> with it either. I don't see any DC shorts on the transformer. I've had a
> few of those go bad in the past. They take out the 20 amp line fueses and
> I can measure the short. So to recap
> 1. The soft start fuse is blowing
> 2. It doesn't blow with the rectifier/filter board disconnected
> 3. All components have been replaced on the rectifier/filter board.
>
> What am I missing??
>
> 73
> Ken K4ZW
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>
>
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