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Re: Connectors on an 847


Spooky... Strangely enough my power switch (which was already on its way
out) broke completely when I did the headphone mod you describe. I used the
MOX switch assembly (which I never use anyway) to replace it.

There's a detailed description of the headphone mod and how to take the unit
apart on

Cheers, Howard

----- Original Message -----
From: Jon Ogden <na9d@mindspring.com>
To: Howard Long <howard@howardlong.com>; <amsat-bb@amsat.org>; David M.
Tipton, PhD <tiptond@psi.com>
Sent: Friday, September 22, 2000 12:54 PM
Subject: Re: [amsat-bb] Connectors on an 847

> on 9/22/00 2:03 AM, Howard Long at howard@howardlong.com wrote:
> > o    Preorder a couple of power on/off switches from Yaesu. The power
> > is the only piece of mediocre design on the radio. Neither the mechanism
> > the contacts are up to the job. For this reason I switch the radio on
> > off at the power supply.
> That's interesting.....I've had mine for a year now with no power switch
> problems.  I'll have to watch out for it.
> One other thing is that you *may* need to modify the headphone circuitry.
> Some of the models have an attenuator pad in them for using high impedance
> headphones.  If your headphones distort when you turn the volume up more
> than half way, you will need to do this.
> Remove the front panel and locate the headphone board.  If possible remove
> the board.  You'll have to find a way to remove the retaining ring of the
> headphone plug.  I could not so I just had to do the surgery with the
> in place.  There are 4 resistors on the board from what I remember.  The
> to be removed should be red or marked with a red dot.  Remove them.
> Resistors R8501 and R8502 should remain on the board.  The schematic Yaesu
> provides with the radio doesn't even show the resistors that should be
> removed.  There was a more exact discussion of this on either this
> or the Yaesu reflector in January of this year I think.  If in doubt,
> contact Mike at Yaesu and he'll walk you through it.
> 73,
> Jon
> NA9D
> -------------------------------------
> Jon Ogden
> NA9D (ex: KE9NA)
> http://www.qsl.net/ke9na
> "A life lived in fear is a life half lived."

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