[TowerTalk] Tic rotor potmeter replacement?

[john at kk9a.com]

TIC General used the Bourns model 3590S-1-501 potentiometer in some of their 
units and at one time as replacement parts.  They are not water proof.

John KK9A



To: " "Tower Talk"
Subject: Re: [TowerTalk] Tic rotor potmeter replacement?
From: "Dick Green WC1M" <
Date: Fri, 19 Jun 2009 14:19:57 -0400
List-post: <towertalk at contesting.com">mailto:towertalk at contesting.com>

Henk,

The most recent pots I got from TIC are Vishay model 534. It's a 10-turn
pot, 500 ohms +/- 5%, linearity +/- .25%.

However, I've seen quite a few of these pots fail due to moisture ingress,
sometimes accompanied by freezing. I have recently obtained what may be a
superior replacement: Bourns model 3590S-1-501. This pot has identical specs
and dimensions to the Vishay pot, but has a plastic body and shaft, as
opposed to the Vishay's metal body and shaft. Here is a link to the spec
sheet:

http://www.bourns.com/data/global/pdfs/3590.pdf

N3RS told me he replaced the stock pot with the Bourns model quite a few
years ago and has not had any problems since. He believes the Bourn pot is
better sealed against moisture than the pot provided by TIC. I have three of
the Bourn pots on hand but have not attempted to disassemble them to see if
they are in fact better sealed. My sense is that moisture trickles down the
shaft and into the body of the pot because the shaft is in a vertical (up)
orientation. Although the motor case is sealed, eventually moisture finds
its way to the pot, either through leaks in the case or condensation. If the
Bourn pot has an O-ring or some other type of seal at the shaft-body
interface, it may be more resistant to moisture than the Vishay pot.

73, Dick WC1M

> -----Original Message-----
> From: Henk Remijn PA5KT [mailto:pa5kt at remijn.net]
> Sent: Friday, June 19, 2009 11:31 AM
> To: Tower Talk
> Subject: [TowerTalk] Tic rotor potmeter replacement?
>
> Hi,
>
> I own a Tic rotor 1032 and the potentiometer stopped working. I know it
> can be a cabling problem, but if the potmeter is the problem I want to
> have the right parts available I would like to buy a replacement potmeter.
>
> Does someone know what potmeter is inside?
>
> 73 Henk PA5KT
>
> --
> Henk Remijn PA5KT
> email: pa5kt at remijn.net
> www: www.remijn.net