Tom Rauch wrote:
>
> > Just replaced the 2 resistors in the control box of the
> > g800 AGAIN, this time with 120 ohm 2 watters, if they go I
> > am going to chuck this piece of s__t out the door & put up
> > the ham 4.
> > Mark
> > ps:the last set of 120ohm 1 watters lasted less than 2
> > weeks, Yaesu claims their aren't any problems with the
> > design of the g800s control box, the first set of resistors
> > died at 3 months (they supplied replacements) the second at
> > 13 months (send it in we will fix it for around $100), this
> > is now the 6th pair of resistors & the control board has
> > burnt through so bad that I have had to replace traces with
> > wire! The g800s control box is JUNK!!!
>
> You'd be better off taking a breath of fresh air and finding out
> what OUTSIDE the control box is making it fail. The most common cause
> of problems is RF getting into the rotor cable.
I am running 160 watts on 2 meters & 25 watts on 432, both
tx lines are hardline.
>
> Most common is poor lead dress. People commonly like to
> install rotor cables in overhead spans. Not only is that a lightning
> hazard, it just begs for severe RF problems.
The rotor cable comes down the inside of the tower, is tied
off to the tower leg every couple of feet, from there it
follows the wall of the house for 4 feet before entering the
shack.
>
> I knew one guy who had problems with his rotor box (a Ham-M), burning
> it up over and over again. Turned out an antenna about 50 feet from
> the rotor cable was causing so much RF current to flow in the
> control box some resistors actually smoked.
>
> Exactly how do you route the leads, and how are all the antennas
> installed? Do you use baluns? Do you bring all the cables down the
> tower taped to the legs to ground level? Are the cables buried? Do
> the cables come into the house at ground level? Do you shunt feed a
> tower or use a Slopper antenna that exites the tower and everything
> on and around it with high RF currents?
>
All that is on this tower are 2 m^2 2m5wl's on a fberglass
crossboom & an m^2 432 13wl 7 feet above them. I am not
running high power on 2 or 432 right now so it's not the
problem. All cables are roted down the tower legs to about 3
feet off the ground & then a 4 foot run along the house wall
to the shack.
>
> 73, Tom W8JI
> w8ji@contesting.com
Mark
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