[Amps] titan 425 dimming, drop in power, hv

[gudguyham at aol.com]

Hello Alek Happy New Year, the Titan 425 step start circuit works on the premise that the 28 vdc control voltage power supply and hence the 28vdc step start relay will automatically have a slight delay coming up after the main switch is turned on.  The 28vdc step start relay cuts out the step start resistor which has a fuse in series with it.  If there is a major PS short the step start fuse will blow and the amp will go dead.  OTOH if the step start relay does not engage to short out the resistor, the resistor will get very hot just supplying idle voltages to the amp.  If allowed to saty that way long enough the step start resistor will get so hot and start smoking until it opens up.  The Titan 425 transformers are well know to failure as they get up in years.  i have already done 3 replacements.  The chap with the smelly power supply here should be able to get his nose in there and find the culprit.  Lou



-----Original Message-----
From: Alek Petkovic <vk6apk at bigpond.com>
To: AMPS <amps at contesting.com>
Sent: Sun, Jan 7, 2018 10:36 am
Subject: Re: [Amps] titan 425 dimming, drop in power, hv

Here's a total stab in the dark.

Does it have a step start resistor/relay setup?

If so, the relay may not be coming in or the contacts ar not making, 
which will leave the resistor in circuit. When you draw current through 
it for a prolonged period, it will get might hot and perhaps be the 
cause of that smoke.

73 and good luck.
Alek. VK6APK

On 6/01/2018 6:12 PM, mike george via Amps wrote:
> thanks to all who responded to my post on 12-11-17 on this amp problem. i tried to follow every suggestion from all who responded till i got to the filter lytics. was not sure so went ahead and dropped too much $$ on a re-cap kit on ebay. sadly the problem remains. i thought at first i caught a slight smell when the problem occured but dismissed it as the wood stove fumes from next room. this time with new caps installed i ran it a little longer and tried to touch up the tuning. yup, the smell was stronger and i stuck my head under the table to see smoke. i could not kill power, remove the cover and look for the source in time to see it. after voltage safty check felt for hot part but found none. i dont think a rf deck problem is the cause, but not real sure how to proceed finding this. any further ideas will be greatly appreciated. 73 mike  Kilowatt Six
> No High Voltage. how could i know a vanity call sign could come true.....
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