SB 200

[David Hollander]

Hi Jan - I received a bunch of questions on the SB-200 after my posting
so I am also posting this to the list.

First thing I would check are  the grid resistors, R21 and R22. One of
mine was way off initially causing low out put on the low end of 80
meters. When I put new tubes in thinking that was the problem, it
finally burned up causing me to destroy a new tube (got so hot, the
glass began to collapse). I felt pretty stupid but was glad it was not
an 8877 ($700 as opposed to $100 for a pair of 572's). I would replace
both of these resistors. That solved a major problem that I had for a
couple of years since. As far as 220 VAC, you need to change the jumpers
in the power supply (you will see these on the schematic). You will need
to change the jumpers and of course the plug (I would build an adapter
rather than change the plug). You will get more power out running it on
220 assuming you have 220 in your shack (I do for my homebrew 4-1000).
My amp is stock, no Harbach modifications. Only addition is a muffin fan
for cooling

With the FT-1000MP, I do not hook up the ALC and I let the internal
tuner match the radio to the amplifier. I also have run the SB-200 with
an FT-900 the same way. I would not mess with the input circuits as they
are broadbanded. I originally thought that they were the problem with
low out put power and it turned out to be the grid resistors. Glad I did
not mess with them.

Good Luck,
Dave N7RK

--
***********************************************************
Dave  N7RK -  Webmaster CADXA http://cadxa.org
Phoenix, Arizona         *DXCC Honor Roll*    *WAZ#23 - 75 Meter SSB*

            ex-XE2/N7RK, N7RK/ZB2, VK2ERK, ZM0AJN, WB6NRK, WN6IWX

Boatanchor Collector Extraordinaire preferring Hallicrafters, National
and what ever else looks interesting!

E-Mail: n7rk at dancris.com           Home Page:
http://www.dancris.com/~n7rk

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