Replace the diodes with 1N5408 which are cheap from Mouser and have a much
better safety level than the original diodes. Mouser does not have a minimum
order.
http://www.mouser.com
You will have to increase the size of the holes in the existing circuit board
to accommodate the larger diameter leads of the 1N5408.
However, you need to determine why the diodes "went". Probably due to failing
electrolytic capacitors. You can get suitable capacitors from Mouser at
reasonable costs.
Glen, K9STH
Website: http://k9sth.com
--- On Thu, 3/24/11, Kathy Bookmiller <wb2aio@yahoo.com> wrote:
I know many of you probably consider a SB200 as a driver for your real amps,
but for us QRPers, it is as good as it gets:) I just blew a diode in HV chain.
Now one friend I respect says I should put in the Harbough board, soft start,
etc. Trouble is, that's money I don't wish to spend if I don't have to. Put in
new board is easy to say when you have money, but us poor underpaid nurses....
Taking a look at mine, I noticed there are 3 diodes already replaced in the two
strings by placing them under neath or on the bottom of the board. When I first
looked at it, I thought they had been vaporized:), so this isn't a new problem.
I'm hoping to find something at Radio Shack I could use and just change out the
newly blown diode, maybe even using the trick the previous owner employed of
just putting in the new one underneath to save taking it apart to get at the
top of the board. So was wondering what you guys think or your experiences with
the SB200. I just
acquired it last summer and otherwise has worked really well when I've needed
it.
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|