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Re: Yaesu G-5400B Elevation Indicator



Brad et al:

I had a similar problem; first intermittent, then dead.

Spent a bunch of money to buy the new pot from Yaesu.
Spent a bunch of time and effort to disassemble antenna system.
Spent a bunch of time and effort to disassemble the rotor.

When I got in, I found the pot was fine.  The problem was that Yaesu uses a
very fine wire to connect from the wiper arm to the terminal on the pot.  They
provide strain relief at the terminal by using a piece of tape to prevent the
wire from flexing at the terminal.   This tape was the poor quality
"cellophane" tape I've seen in other places . . . the adhesive weakened, the
tape lifted off the pot body, and the wire flexed . . . until it broke.  Not
Yaesu's finest design!

Since I had a new pot already, I replaced it, but could have repaired the old
one (which is now in the spare parts locker).  To prevent another such failure,
I used a heavier piece of electrical tape to provide strain relief, then backed
it up with a tie-wrap (uv, external type) which combination I hope to last
longer.

So, if you've got the time and patience, I'd suggest disassembly/inspection of
the rotor before ordering the replacement pot.

One other suggestion:  disassembly of the rotor is prone to result in an
explosion of ball bearings with the resultant chase.  Strongly suggest all work
be in some large tub on the work bench to contain the mess.

The above discussion predicated on the assumption that you've followed all the
other good advice on here and have really localized the problem to inside the
rotor.

GOOD LUCK!

73, Jim
wb4gcs@amsat.org


James D. Mayfield wrote:

> Only on this reflector do you have to ask that no flames be sent, for
> asking a perfectly good questions. I used to think that Satellite operators
> we a cut above the 75 meter gang, but I have to wonder when I see guys
> start a message like this. He should not have to!
>
> At 05:20 PM 9/12/98 -0500, you wrote:
> >Excuse the bandwidth because I know this has been asked before. (No
> >flames, please!) I didn't save the message because I never thought I'd
> >need it. Shows you how wrong you can be.
>
> Brad, I think this rotor uses a 5volt system, +5 volts to 0 volts, to
> indicated where the rotor is, check to see if there is voltage in this
> range on the meter, if not you may want to see if the 5 volts is getting up
> to the rotor or not. I bet the trouble is with the pot in the rotor that
> turns the 5 volt up and down, as the boom is raised and lowered. This
> should not be much trouble to fix. Good luck.
>
> 73 Dave
>
> *********************************************
>        J. Dave Mayfield KB9BNR
>
> http://home.revealed.net/qste/bnr/kb9bnr.html
>           kb9bnr@revealed.net
>    http://home.revealed.net/qste/sale
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