On 8/8/02 4:22 PM, Joe at w5asp@earthlink.net wrote:
>Finally, capacitors designed for use with industrial motors are very rugged.
>The ones that come from a source like Gainger are expected to live in the
>cruel, harsh external world. (Go look at you outside A/C unit's fan motor
>cap.) If properly installed, they will outlast most amateur antennas. We've
>had them on towers for over 15 years with no failures.
When I put up my tower last year, I refurbished a Ham-M rotator whose
capacitor had gone bad. (Amazing that his 27-year old piece of equipment
worked otherwise flawlessly) Rather than mess with the control box, I
mounted the replacement cap on the tower, near the rotator.
I didn't use a Grainger industrial device. Instead, I bought a 150 uF,
100 V non-polarized cap from radioshack.com. In fact, I bought TWO, just
in case one blew up on me.
To allow for rotator disconnect, I used a couple of trailer hitch
electrical connector pairs. This gave me 8 conductors worth of
weatherproof connectors. (One is wired up opposite the other, so you
can't cross them up.)
One set of connectors is wired to the bottom of the rotator. The other is
wired into a 4" square NEMA box, which houses the capacitor as well. A
U-bolt holds the box to the tower leg. Standard Wireman R1 rotator cable
runs from the box back into the shack.
This arrangement has been flawless. The smaller Radio Shack caps get warm
during rotation, but they haven't failed on me yet. The Grainger devices
would last forever.
Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@arrl.net
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
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