1. You stole that SB-200. Even non-working with good cosmetics $40.00 is a
bargain.
2. I had a similar condition with an old BlackCat 80-10 amp with two 3-500Z's
I picked up at a hamfest for $100.00. It was one of the power supply filter
caps arcing internally.
I own a SB-200 and replaced the power supply board with a Harbach replacement
(new caps, diodes and meter resistor string) and made other Harbach mods. I
have been very happy with the results. Well worth the $$
Randy AB9GO
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Bob Arenella
Sent: Friday, April 12, 2013 9:50 AM
To: Amps@contesting.com
Subject: [Amps] SB-200 Repair?
Picked up an SB-200 amp at a recent hamfest.......I already have an Alpha 86,
but the guy was only asking $40. Good cosmetics, and a once over top to bottom
shows nothing zorched. Removed the tubes, and brought it up slowly on my
variac.
All went ok till the meter showed about 800-1000 volts, then SNAP, SNAP. Did
a top and bottom visual in the dark, couldn't see anything. Unsoldered the PS
output to the plate choke, no joy. Lifted one side of the transformer
secondary and all was fine.
So, probably bad caps and / or diodes. Just replace the diodes / caps with
modern parts or go for the Harbach replacement? I did notice the bleeders got
awfully hot.....why did heathkit use such a low value for these?
All opinions welcome!
Tnx & 73 de bob,
N2OAM
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