[Amps] SB-220 on 6 meters: looking for projects...

[Han Higasa]

GM all,

These photos are of the Bear Electronics in JA6 land,
which is a famous manufacturer of linear amps for amateurs.

I have a few experience to modify TL-922s and SB-1000s for
six-meters, and repair of some 2006As.

I remember some 2006As exhibit low power and high grid
current because of inadequate connection of a load VC.
It was connected by only one stator terminal, just in parallel
to the connection between an output connector and a plate coil.

In another words a plate coil is soldered to an output connector
directly, and a stator terminal of the load VC and the connector
is connected by a ribbon nearly 2-inch long.
The circuit schematic is right, but the RF flow is wrong.

By using two stator terminals and extra grounding pieces
I forced RF current to flow load VC entirely and improved
the effectiveness of the VC, and achieved a good plate
efficiency with low grid current.

de Han JE1BMJ

----- Original Message ----- 
From: "Han Higasa" <higasa at plum.ocn.ne.jp>
To: <Amps at contesting.com>
Sent: Friday, February 08, 2008 7:36 PM
Subject: Re: [Amps] SB-220 on 6 meters: looking for projects...


> Piacere Joe
>
> You can see photos of modified TL-922 for six meters:
> http://www.bear-el.com/tl-922sp/index.html
>
> and SB-1000 for six:
> http://www.bear-el.com/sb-1000sp.html
>
> HL-2K for six:
> http://www.bear-el.com/hl-2ksp.html
>
> see you soon on six, de Han JE1BMJ
>
> ----- Original Message ----- 
> From: <it9blb at infcom.it>
> To: <Amps at contesting.com>
> Sent: Thursday, February 07, 2008 9:50 PM
> Subject: [Amps] SB-220 on 6 meters: looking for projects...
>
>
> > I'd like to convert my old SB-220 into a 6meter monoband amp.
> > After a long surfing on the web, I wasn't able to find any
> > dedicated article or complete and tested suggestions to
> > support my target.
> > Any possible good suggestion here?
> >
> > Thanks in advance for any help,
> > "Joe", IT9BLB
> >
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> > Amps at contesting.com
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> >
> >
>
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