On 12/3/2010 3:26 PM, Ron Castro wrote:
> There was an article from a ham in Texas on the internet on modifying the
> 425 for 3CPX800's but I can't find it. I recall it required an entire new
> supply, including a custom-built Hypersil transformer from Peter W. Dahl
> that ran more voltage and current than the original and fit in the power
> supply cabinet. With the higher plate voltage, less drive was required, and
> lower grid current for legal power, but I think the real object was to run
> much more than legal power. The author claimed he tested the modified amp
> at 3.2 kW PEP out..."on a dummy load of course" (yeah, right!). I guess
> everything's bigger in Texas!
yah sure, and he got that 3.2 Kw through RG8X and a PL-259.
73, Jerry, K0CQ
> Like one Texan told me: "Go big or stay home"....
> Ron N6IE
> ----- Original Message -----
> From: "Jim Brown"<firstname.lastname@example.org>
> Sent: Friday, December 03, 2010 1:04 PM
> Subject: Re: [TenTec] TITAN 425 PS maintenance
>> One thing you would need to consider is what other high voltage
>> capacitors are in the RF deck that might need to be replaced with parts
>> rated for higher voltage.
>> As I understand it, the main reason for using higher voltage with 3CPX
>> tubes is that you can achieve legal power with less plate current. I
>> don't know if there would be reduced drive requirement, or less grid
>> current. Since the primary failure mechanism in these tubes is excessive
>> grid current, that's what I would pay the most attention to.
>> Also, I don't know what's in this board, but to get higher voltage, you
>> would probably have to replace the power transformer as well.
>> The only condition under which I would look at this board as a
>> replacement is if most of the power supply went up in smoke. :)
>> 73, Jim K9YC
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