| Author |
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Allagator
| | Posted on Friday, October 03, 2003 - 7:37 pm: | 
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I have a Varmint XL-350 that makes me sound like im running my radio off a battery charger !!!! could it be bad filters or what and if it is what should they be ???????
Thanks Allagator |
307
| | Posted on Friday, October 03, 2003 - 8:35 pm: |
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Hmmm..Most likely the diodes in the HV ladder are going bad...The XL-350 is an AC configuration and really does not have so called filtering except on the AC side. I would replace all 8 of the HV (1000V-PIV) diodes and possible the doubler capacitors. This should rid the problem.
307 |
Bullet
| | Posted on Saturday, October 25, 2003 - 12:05 am: |
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since its an older amp,
id go ahead and up grade the rectifier diodes like 307 said. i changed mine to the 3amp 1000piv i would also change out the hv capacitors anyway, i mean if you plan on keeping it for many years these things will need replaced in the near future anyway and they dont cost much.
the ones i put in my phantom 500 were like 2.95 a piece. i changed the caps from the stock configuration of eight 100uf @ 350volts to a more compact size of four 220uf @ 450volts.
looks much neater under there and shows better power with the new caps/equalizer resisters and hv bleeder setup.
i wanted to up grade it after refitting my sb220 and wanted the phantom to have some of the the same design in the hv section.
ive got another phantom to redo ive got the 5408 diodes and the nichon 220uf 450volt caps comming from rf parts its gona be about 14.75 in parts to redo this so that's cheap enuff for anyone. |
Bullet
| | Posted on Saturday, November 01, 2003 - 5:19 am: |
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after getting my parts and starting work on this i have seen that my old amp guy had made a mistake you cannot replace 8 100uf 350volt caps with just 4 220uf 400volt caps.
he forgot a bank of caps all together in the hv section were they run paralle!
in stock form its fitted with 2, 100uf 350vt caps for the low side and 2, sets of 3 100uf/350vt caps for high stage. so i ended up installing 8 220uf/400volt caps in the hv section and used the 5408 diodes for the recifiers.
seems to be working a bit better than before.
the amp my old amp guy worked on i uninstalled his cap work and used some good caps that were the stock ones for d&a, amps 100uf/350vt but im having a relay issue with this one.
i hope this clears up any confusion of the post above if you were adding up the voltage to be handled by the caps it fell way short huh!
i wonder how he missed it! i didnt think about it till i started to re fit my other phantom with new caps and thought hey this aint right.
i wondered why it was acting odd on hi stage im sure now this was why. its a wonder it didnt let its smoke out.
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