[Amps] SB-200 power supply diodes

[Glen Zook]

I disagree!  Yes, you do have to enlarge the holes to use the 1N5408.  However, the added protection of both the higher current rating and the surge of the 1N5408 over the 1N4007 will assure that if one of the electrolytic capacitors "goes" then the circuit breaker (or fuse, depending on the linear) will open before any of the diodes short and that, in turn, will save the transformer.

That usually will not happen with the 1N4007.

I realize that the 1N5408 costs a little more than the 1N4007.  I pay 2.7 cents each per 1N4007 and 11 cents each for the 1N5408.  But, for less than a dollar the added protection of the 1N5408 is well worth the money.  I do "stock" 1N4007 diodes because they work in so many applications.  However, for high voltage in linear amplifiers I use the 1N5408.

Glen, K9STH

Website:  http://k9sth.com


--- On Sat, 3/26/11, Jim W7RY <w7ry at inbox.com> wrote:

Agreed Jim!  3 amp diodes are an overkill on the SB-200 and SB-220.

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From: "Jim  Garland" <4cx250b at muohio.edu>

Kathy,

I'd advise replacing the diode string in your SB-200 with 1N4007 diodes instead of 1N5408. Not that there's anything wrong with the 1N5408, but the holes in the circuit board will have to be drilled out to make them fit. The 1N4007 will be a perfect fit, and with a 1A/1000V rating, will be more than adequate for an SB-200. You should probably also replace the elderly electrolytics in the amplifier while you have it apart.