ACOM 1000 HV Bridge rectifier replacement?

[n2len]

Hi everyone,
I am hoping that someone can suggest a replacement rectifier...
I have been troubleshooting a problem with my Acom 1000 amplifier.
I replaced some capacitors and found a blown diode/rectifier on the HV bridge.
There are 4 of these diode rectifiers.
Part number is BY6 by Diotek
Rated at 6KV at 1amp (Not available in USA)    Is there a drop in Sub available in the US?
I can order a new replacement upgraded rectifier from Acom in Bulgaria for $7.00 each.
I would have to replace all four, which I am prepared to do anyways.
But before I order the replacements, It was suggested to tie 6 1N4007's together to replace the blown diode.
I would like to try this to confirm that this is the last remaining fault with the amplifier and hopefully will complete a full power cycle instead of giving a auto protection fault LCD reading?

I've checked around the net, Found K2AW/SK HV modules, etc...but no longer available.
Here is a picture of the HV bridge and Capacitor bank and a second picture of the newer updated Rectifier replacements...

Thanks,
Len

[KA2DZT]

I wouldn't use the 1N4007s,  I use (1N1540s not) 1N1508s rated 1KV 3amps.  Never had one fail.  I think I got the number right (wrong). TNX to Pete 1N1508 is correct.  I buy 200 of them each order.  Probably less than $20.  Check on ebay.

I put a 470K 1/2W resistor and a .01ufd 1KV cap across each diode but many will say you don't need the cap or resistor.  I use them anyway.  You may not have enough room for all of this.

I also use way more diodes in series than the B+,  probably at least 4-5 times the B+.  2500VDC supply would have at least 6 diodes in each of the four legs of a FWB rectifier.  That gives you 12 diodes in series on each side.  Remember that a 2500VDC supply would have a peak AC voltage of 1.4 times the 2500 volts.  That's about 3500 vac.  3 times 3500 volts is about 11KV.  The diodes are rated at peak inverse volts (PIV).

What is the B+ for the amp??

Fred

[Pete, WA2CWA]

1N1540's are stud mounted 3 amp rectifiers. I think you're probably referring to 1N5408, the axial leaded 3 amp version.

[KA2DZT]

Thanks Pete,

I thought that number wasn't right,  I'll correct my first post.

Fred

[WD5JKO]

That BY6 has some lofty ratings:

http://doc.chipfind.ru/html/diotec/by6.html

I would look at the "as-used" application to see what the degree of over-kill the Acom designers chose.

For a possible replacement, look at Rectron:

http://www.mouser.com/Semiconductors/Discrete-Semiconductors/Diodes-Rectifiers/Rectifiers/_/N-ax1mb?P=1z0z5fm&Keyword=rectron+diode&FS=True

Spec's
http://www.mouser.com/catalog/specsheets/hvp.pdf

Take note of the continuous and surge current capability. Also HV diodes have multiple PN junctions in series inside, so the forward conducting drop will be several volts to 10V or more depending on the PIV rating of the diode.

The BY6 has <6V drop, so it likely has six PN junctions inside. The link above for BY6 has a PDF data sheet link at the top of the page...There are more detailed spec's there.

Jim
Wd5JKO