Re: [TenTec] Titan 425 Transformer needed

["Ron Castro" <ronc@sonic.net>]

The primary to secondary short is a known problem with the 425's, and mine 
went back to the factory some years ago for a replacement which is still 
running fine today.
You can't go wrong with a Peter Dahl transformer as a replacement, but I 
would suggest calling them on the phone.  Here is a link to an article about 
beefing up the venerable 425 which is good for future reference even if you 
keep the finals and the plate voltage the same.  The author used a specially 
built Peter Dahl transformer for the project which turns the 425 into 3.5 kW 
ground pounder!
http://www.hamradiomarket.com/articles/Titan%20P%20Hybrid.htm

        Ron N6IE
     www.N6IE.com


----- Original Message ----- 
From: "Carlin Royal" <n5oe@nctwb.net>
To: <tentec@contesting.com>
Sent: Saturday, August 18, 2007 11:49 AM
Subject: [TenTec] Titan 425 Transformer needed


> Sorry for the long delay on the re-post. After replacing/upgrading the
> rectifier board, installing new filter capacitors the initial problem is
> still there. I carried the amp to a local repair shop and it has been
> determined for sure the secondary leads have shorted with the primary in
> the transformer. SOOOO I am in need of a new transformer for the Titan
> 425 at this time. Since I have already come this far money wise and time
> wise, I think it would be best to get a "really good" transformer this
> time. I have emailed Peter Dahl with no response, are they still doing
> this sort of thing for amateur use?
>
> _"I have a Ten Tec Titan 425 that I have only had myself for about 6 
> months now.
> The amp when I received it had 1 bad HV capacitor in the power supply. Due 
> to
> lack of funds at the time I replaced the one known bad capacitor. A few 
> months
> later I was operating the amplifier during a cw pileup for about 30 
> minutes, I
> set everything on standby and went to lunch. When I returned to the shack 
> I
> find the amp had blown one of the 20amp fuses in the supply.
> After checking in the PS, I found that R1 the 10ohm 25watt wire wound 
> resistor
> on the rectifier board had went open. I replaced the blown resistor and 
> powered
> the amp back up, this time again blowing a 20ampfuse and the same 
> resistor. Ten
> Tec advised to replace the original rectifer board with a new one, (82112 
> rev E
> I beleive) since they thought some diodes were probably leaking and was 
> the
> cause of all my troubles. Now after replacing the old rectifier board with 
> the
> new one from Ten TEc, I power the amp on and it blows another 20amp fuse 
> but
> did not appear to fry the resistor this time. Here is the main question to 
> the
> list; Could I have another bad capacitor that is failing under high 
> voltage
> since they do not read any shorts on the VOM when individually beng 
> tested. I
> have on order 8 new 400uf 450v caps from Newark Electronics and will be
> replacing them this week, but I am looking for more input as to the 
> trouble. It
> just seems odd to me that when sitting idle for just 3
> 0 minutes the thing went south and now I have had all this trouble. 
> Hopefully
> I am on the right track and it will be one of the caps in the PS, but 
> would be
> interested to hear any other areas that I might could check within reason 
> here
> on the very limited bench. Thanks for any advise/comments.
> 73 "_
>
>
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec