Skip S Isaham wrote:
>
> I came across a used SB-1000 real cheap with blown, missing, and
> questionable parts. Would anyone be able to provide me with the
> following, please?
>
> Inductance value and tap locations of the 160/80 toroid tank coil? I'd
> really like to know what core material Heathkit used for this coil and
> who sells it. (or an equivalent)
> The original coil in this amplifier is damaged.
>
> The "owner/operations manual" mentions a retrofit plate choke
> ("shouldered version") should be installed. Anyone have information about
> the newer plate choke value?
I replaced the choke in mine with one purchased from Ameritron
<http://www.ameritron.com>. It works fine on all bands 160-10, including WARC.
Cost about $25. The AL80B choke is the one to ask for. I wouldn't be surprised
if they also have the 'L' network toroid that you refer to -- the amplifiers are
basically the same. Check your bandswitch very carefully, especially the
contacts for the 160-meter tank capacitor padder -- they tend to arc there. I
had to replace a contact. Also, I added the 'corona washer' to prevent arcing
(it seems to have done so). I'll quote my discussion with Tom Rauch, the
original designer of this amp:
> > But where exactly should I put a washer?
>
> It goes on the 160 meter padding capacitor ground lead, where it
> connects to the lug on the switch. It fits OVER the lug, before the
> wire is attached.
>
> >How big is it and what is it made of?
>
> I don't recall exactly, but I think it is about 3/8 inch OD with an
> ID big enough to just fit over the lug. It is brass, and tumbled to
> remove burrs.
>
> Avoid sharp points or edges on the washer. Solder it over the lug,
> and slip the buss wire through above it. Flow the solder intop
> smooth connections.
Good luck. After fixing mine up I get an easy 800 watts CW or more on all bands
except 10 meters (700 watts).
73,
Vic, K2VCO
Fresno CA
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