[Amps] No grid current meter on FL-2100B?

[Mike Waters]

Hi Jim,

I appreciate your thoughts, and I just finished sharing them with the ham
on 40m. He concurred with you about the SWR meter!

I just e-mailed him W8JI's web page on metering amplifiers (he only has
e-mail, no web access). As long as the SWR meter's full-scale current is
low enough, I'm almost certain this can be done.

He wants to directly ground the grid for DC. At this point we need to come
up with a bias supply circuit, preferably adjustable. Zeners in series with
the cathodes are a last resort, since they generate and waste so much heat.
Maybe a pass transistor.

Thanks again to everyone else who replied. And we're still open for
suggestions.

73, Mike
www.w0btu.com

On Mon, Feb 23, 2015 at 10:29 PM, Jim Thomson <jim.thom at telus.net> wrote:

> Date: Mon, 23 Feb 2015 08:09:31 -0600
> From: Mike Waters <mikewate at gmail.com>
> To: "amps at contesting.com" <amps at contesting.com>
> Subject: [Amps] No grid current meter on FL-2100B?
>
> I'm trying to help a friend (in another state) convert his Yaesu FL-2100B
> from 572Bs to GI7-BTs. I just noticed that there is no grid current meter!
>
> Is there an easy way to convert the SWR meter to monitor grid current? A
> Google search turned up nothing about adding grid current monitoring to the
> FL-2100*.
>
> TIA.
>
> 73, Mike
>
> ##  I had a 2100B back in the 70s.  Myself and several other 2100B owners
> noticed the
> swr meter was  semi useless.   The indicated swr rose as the po
> increased.   I once heard
> an old geezer remark to his buddy that he never ran it more than 400w pep
> out, since at 600w
> pep out, the swr increased too much !   Re-using the swr position as a
> grid meter would be a
> superb idea...and use an external, real swr meter outboard.  Is there an
> online 2100B schematic
> available ?   This may well be doable.
>
> Jim  VE7RF
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>