[TowerTalk] Yaesu G-2700SDX
Chuck Lewis
clewis@knology.net
Tue, 9 Oct 2001 22:53:55 -0500
Luis,
I had similar symptoms with my G-800SDX. My problem was solved when I dried
out the moisture inside the connector at the rotator. Remember, these are DC
operated rotors, and any conductivity between the motor drive terminals and
potentiometer leads can affect the voltage seen by the desktop indicator,
making the needle swing wildly any time the left or right rotation voltage
is applied. In my case some of the approx. 12 VDC was appearing at the top
of the potentiometer (either - or + depending on left or right) changing the
voltage sensed by the desk controller. Check resistance from 4 or 5 to 1 and
2 (I am assuming the pinouts are the same between the 800 and 2700). I think
this should be infinite. Also, slight conductivity from the pot terminals to
ground, changing over time, can vary the voltage on the center terminal of
the pot (slider) and cause the azimuth needle to move when the desk unit is
turned on (the desk unit applies potential to one side of the rotor-mounted
potentiometer) and the needle will have no relationship with the antenna
azimuth, because the apparent resistance is a function of the "mini-short".
I found a puddle of water and insect grunge in the connector, which I dried
out. No more problems.
Recent postings on this reflector have discussed many options for
waterproofing/backfilling such connectors; you can choose your favorite. In
my case, plain old vaseline filling both the backshell and the business end,
combined with tape and sealant have kept this from recurring. Yaesu's
flexible boot seems to have done little to prevent either direct influx of
rain water or condensation from temperature/humidity cycles.
I like the variable speed which the Yeasu's DC motor affords, but this
little bug gave me fits for a while!
Chuck, N4NM
----- Original Message -----
From: "Luis Sutil Teixeira" <ct4nh@mail.telepac.pt>
To: <towertalk@contesting.com>
Sent: Tuesday, October 09, 01 4:01 PM
Subject: [TowerTalk] Yaesu G-2700SDX
>
> Having lots of trouble with my rotator Yaesu G-2700SDX.
> 1 - After switching on the desk controller, notice aleatory movement of
the
> needle without touching the controller. Going back anf forth, until it
goes
> to a position sometimes completely different from the position of the
> antenna.
> 2 - RF affects the controller as when TX needle moves slightly changing
its
> position.
> 3 - Checked resistances between the pins of the rotator socket (at the end
> of the cable in the shack):
> pin 1 - 3 : 518 ohms....1-2 : 290 ohms 2-3...235 ohms but values change
> (cable???)
> Would like to hear your opinions about this nightmare...and possible
> solutions.
>
> Tnx de Luis, CT4NH
>
>
>
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Trylon Titan towers, coax, hardline and more. Also check out our self
supporting towers up to 100 feet for under $1500!! http://www.anwireless.com
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