Semi-Heath-related ?s...

[Multi-Volti Devices]

Good advice, but the poor guy just admitted his knowledge level isn't too
high...I think this suggestion will bury him further...

:O)

Murray
----- Original Message -----
From: mike bryce <prosolar at SSSNET.COM>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Saturday, October 21, 2000 10:08 AM
Subject: Re: Semi-Heath-related ?s...


> John..
>
> Hold the phone!
>
> what you want to do is very simple. You need a good high impedance switch
> that will then switch to ground yet won't load down the other two rigs..
>
> a transistor?
>
> nope!
>
> try a power MOSFET!
>
>
> to use the very common "N" channel types, you'll need to build a small
> transistor level converter to switch the fet. This level converter is
simple
> and is just a pair of transistors, one pnp and one npn.. the fet needs to
> see at least +10 volts on its gate to be fully enhanced and then zero
volts
> to turn off.
>
> since the gate drive current  is just about nil, you just parallel any
> number of fets. since each one will switch to ground, all your muting,
> keying and other problems are gone.
>
> now, just to make things interesting.. you could easily add on an internal
> sidetone generator, a multiplex the outputs using a 4016 or even a T/R
> antenna relay switch.
> --
>
>
> sniff!?
>
>
> I smell a QST article here!
>
>
> Mike Bryce WB8VGE
> SunLight Energy Systems
> "Electricity at the speed of light"
>
> > From: John Clifford <johnclif at ix.netcom.com>
> > Reply-To: johnclif at ix.netcom.com
> > Date: Sat, 21 Oct 2000 06:26:25 -0700
> > To: HEATH at LISTSERV.TEMPE.GOV
> > Subject: Semi-Heath-related ?s...
> >
> > Greetings,
> >
> > I'm trying to use my MFJ memory keyer to both key my HW-9, and mute my
Drake
> > R8A.
> >
>
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