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Re: Preamp bypass circuit

> Date:          Sat, 17 Feb 2001 23:44:30 +1100
> From:          Hamish Moffatt <hamish@cloud.net.au>
> To:            amsat-bb@AMSAT.Org
> Subject:       Re: [amsat-bb] Preamp bypass circuit

> On Wed, Feb 14, 2001 at 08:41:20PM -0600, Dave Metz wrote:
> > This is a one IC circuit so the construction is simple.  Yes, you will have
> > to go inside your 847 and reroute the PTT connection from the mic jack
> > to the rear apron of the radio to a connector and then route it back in
> > to the PTT circuit again.  You can also steal the power for the squencer
> > and the ground connection through the same connector.
> Why not put the sequencer in line with the microphone, instead of modifying
> the radio? There is power available in the mic socket too.

> Hamish
> -- 
> Hamish Moffatt VK3SB <hamish@debian.org> <hamish@cloud.net.au>

Dear Hamish,

There are a couple of good reasons.  First off, why not modify the radio?
You bought it to use didn't you?  Next, having an extra set of microphone
connectors laying on the bench is not exactly convienent.  Nor are in-line
cable type mic connectors all that available.  Plus, the power supplied
to some microphones (by no means all) is usually current limited or
restricted to 8 volts or lower.  My squencer requires 13.8 volts to 
operate some of the mast mounted relays.  

I don't think I own a radio that has not been modified in some way.
No, I am not worried about the resale value.  Well done mods will
not affect resale value in any way.  In most cases, added features
will enhance the value of a radio.  Hams have always modified their
equipment.  That's part of the fun of the hobby!

--73-- David WA0AUQ

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