> Instead of piston trimmers you might want to try ARCO
> padders (postage stamp size that can tolerate higher levels
> of rf current) or small air variable capacitors. I have
> nfound both at reasonable prices at this site:
A generic statement that has merit in this subject
"Q is everything" and the Q of an Arco cap ("padder") is probably
no where near as good as a decent piston cap.
Ebay provides the occasional deal on nice piston caps. If you're
not at a critical current location, the A49 piston caps in the
following sale ad work for some applications.
http://www.hamtronics.com/sale.htm
s.
> http://www.danssmallpartsandkits.net/
>
> 73 and aloha, Eric KH6CQ
>
> --- On Sun, 6/27/10, Tim <tahr...@...> wrote:
>
> From: Tim <tahr...@...>
> Subject: [Repeater-Builder] Piston Trimmer Voltage Rating
> To: Repeater-Builder@yahoogroups.com
> Date: Sunday, June 27, 2010, 11:18 AM
>
>
>
>
>
>
>
> Â
>
>
>
>
>
>
>
>
>
> Hi folks,
>
>
>
> Am just finishing up the 6 meter heliax duplexer project,
>
> and am getting some pretty good numbers. (3 'cans' on
>
> each side, >90dB notch & about 1.2dB 'pass' attenuation)..
>
>
>
> Anyhow, I used some Johanson piston trimmers that I had,
>
> but evidently they are a bit shy on the working voltage
>
> rating, as the one closest to the transmitter (80 w, @53.15)
>
> didn't quite cut the mustard! A nice arc hole in the piston.
>
>
>
> Anyhow, was wondering what the working voltage is for
>
> these guys.
>
>
>
> Guess I need to look around for some substitutes.
>
>
>
> Thanks,
>
>
>
> Tim W5FN
>
> Utopia, TX
>
