|[AMRadio] Switch for GK 500A,B,C|
ars-w5jo at brightok.net
Sun Sep 13 15:56:56 EDT 2009
A while back I posted here looking for the Antenna Coupling Switch
for my GK 500A. One of the shorting fingers burned on it and
another had been so hot that it lost contact with the wafer side.
Several fine gentlemen had switches that they offered but none were
indexed to the marks on the panel so I continued to look hoping that
I could find one.
My search took me to MFJ parts via Ameritron. In the GK 500 series
the switch has 7 positions and the original was special order from
Centralab series 231. Electro Switch Corp. (electro-nc.com) has the
rights to this particular switch and it is their E4 Series.
However, none of the stock switches are made to progressively short
6 positions. They would build and supply what I needed for wafer
replacement, cost ~$85.00. The problems were I had to order through
one of their retain sales outlets like Mouser, Allied, Digikey, etc.
but the drive shaft for the wafer is now different.
Ameritron uses a two wafer band switch from Electro Switch model E4
in their AL 1200 and 1500 amplifiers that would do the job. The
problem is the cost ~145.00. Since I have owned this this King
since 1994 and I received it from the original owner, I decided to
go this route. Installation is pretty straightforward, requiring
you establish which position you want for #1 then moving the
opposite stop one place farther down the line. The switch is a 1
pole 17 position switch and once you have decided which positions
you will use, one jumper wire must be installed on the switch to
make it work.
You have to remove the front wafer and only use the rear one that
comes on the switch. Then you have to cut the shaft to 1/2 inch
length and the wafer drive appropriately. This particular switch
will short only 5 positions consecutively but there are two more
shorting contacts located further around the wafer that can be made
to give the needed 6 pole short.
So after Grand Ole UPS freight charges I have over $160 dollars
spent. But the switch looks and acts like the one that was there.
Another reason for mentioning this switch is the same thing is used
in the final tank to switch bands. This is an expensive way to go,
but I decided to do it to keep the radio as it was both electrically
and operationally. I guess I am happy now.
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