FRED Rectifiers

[David Root]

Me neither, but I only use UF4007s in bias supplies and across relay coils.

The 220AC soft recovery packages have gotten so cheap I use them in all HT supplies.

[glasman]

I also use UF4007 in my amps, which a hifi friend hinted me towards.

No sure I can really hear any difference between regular 1N4007s and the UF4007s.

Not sure that I hear it as well, but I can SEE the difference on a scope. So it must be gooder .

Gary

[lovetone]

They're good for hi power hi fi sound, i'd never put one in my guitar amp.

Which diodes do you recommend? part number I mean.

There are quite a few different type's mentioned not sure which one you go with.

Geoff

[renshen1957]

I would still use two in series for 1200V in this specific example though. I normally use two single 1200V FREDs or a double 1200V FRED, which takes up less space. I even have some 1800V FREDs which I'm holding for a Music Man iron ODS (700Vp).

I agree, the rule of thumb is that you want a PIV of 3x your DC voltage. 1200 would be about the minimum I would use.

In my amps I use 3 UF4007's (1000V PIV / 1 AMP) on a side.

Gary

Hi Gary,

I use UF4007s, too, I still incorporate capacitors and a few resistors as "hash" filters just as when I used 1N4007 to eliminate switching noises. Old habits are hard to break. I can't complain about the price on the UF4007.

Best Regards,

Steve

[glasman]

I would still use two in series for 1200V in this specific example though. I normally use two single 1200V FREDs or a double 1200V FRED, which takes up less space. I even have some 1800V FREDs which I'm holding for a Music Man iron ODS (700Vp).

I agree, the rule of thumb is that you want a PIV of 3x your DC voltage. 1200 would be about the minimum I would use.

In my amps I use 3 UF4007's (1000V PIV / 1 AMP) on a side.

Gary

Hi Gary,

I use UF4007s, too, I still incorporate capacitors and a few resistors as "hash" filters just as when I used 1N4007 to eliminate switching noises. Old habits are hard to break. I can't complain about the price on the UF4007.

Best Regards,

Steve

Back in the "old" days the practice used to be a .01uf cap and a 470K resistor across each diode in a string. The resistors were used to stablize the voltage drop across each diode. The first power supply I ever built as a kid was for a 4-1000A HF linear amplifier. It used a string of 10 diodes a side with a B+ of about 3KV. Nothing like the smell of the ozone from a good transmitting tube .

Yes, the UF4007 is cheap, only a couple cents more than the 1N4007.

Gary

[renshen1957]

I agree, the rule of thumb is that you want a PIV of 3x your DC voltage. 1200 would be about the minimum I would use.

In my amps I use 3 UF4007's (1000V PIV / 1 AMP) on a side.

Gary

Hi Gary,

I use UF4007s, too, I still incorporate capacitors and a few resistors as "hash" filters just as when I used 1N4007 to eliminate switching noises. Old habits are hard to break. I can't complain about the price on the UF4007.

Best Regards,

Steve

Back in the "old" days the practice used to be a .01uf cap and a 470K resistor across each diode in a string. The resistors were used to stablize the voltage drop across each diode. The first power supply I ever built as a kid was for a 4-1000A HF linear amplifier. It used a string of 10 diodes a side with a B+ of about 3KV. Nothing like the smell of the ozone from a good transmitting tube .

Yes, the UF4007 is cheap, only a couple cents more than the 1N4007.

Gary

Hi Gary,

""I love the smell of ozone in the morning... The smell, you know that electical smell... Smells like ... victory"

best regards

steve