Polypropylene would be an excellent choice.
----- Original Message -----
From: "Karl-Arne Markström" <sm0aom@telia.com>
To: <amps@contesting.com>
Sent: Tuesday, March 15, 2005 4:31 PM
Subject: Re: [Amps] nylons
> Nylon should probably be avoided entirely in strong RF fields.
>
> The dielectric material property list in ITT Reference Data for Radio
> Engineers
> lists the dissipation factor of nylon as about 0.022 at 1 MHz , 0.02 at
> 100 MHz and 0.012 at 3 GHz
> (actually decreasing with frequency).
> This is about two orders of magnitude worse than the best plastics and
> ceramics.
>
> Coupled with its low softening point and dielectric strength, it seems
> that nylon is a
> low-priority choice as an RF dielectric.
> Much of the same also goes for acrylic plastics (Plexiglas and Lucite).
>
> 73/
>
> Karl-Arne
> SM0AOM
>
> ----- Original Message -----
> From: "David Kirkby" <david.kirkby@onetel.net>
> To: "John Irwin" <crazytvjohn@yahoo.com>
> Cc: <amps@contesting.com>
> Sent: Tuesday, March 15, 2005 9:06 PM
> Subject: Re: [Amps] nylons
>
>
>> John Irwin wrote:
>>
>> >dudes
>> >
>> >a large ace hardware store opened here last week , One block away. I
>> >have noticed a lot of nylon items that look a lot like the ceramic
>> >standoff insulators, they come with a hole in the center,and some are
>> >taped for 6-32 or other simular sizes. lenght every 1/8 inch or
>> >so,diameter 1/4 to 1/2 inch
>> >
>> >How does nylon act in rf? Like in a amplifier as used to support
>> >variable capacitors or inductors? Next to the plate choke.
>> >
>> >Anyone put some in the pi coil and see if it holds up. or does it go up
>> >in smoke?
>> >
>> >thanks
>> >john kb9tc
>> >
>>
>> One other thing I forgot to add is that I have here some Ross HyperSPARC
>> CPUs, which were from a Sun workstation. (Sun did not make this CPU,
>> but a 3rd party did). I know this particular machine had been run 24/7
>> for many years, and never broke down.
>>
>> The heat sinks were attached using some sort of black plastic screws.
>> When I moved the computer, several snapped. The material (probably a
>> nylon) had become very brittle indeed. But these HyperSPARC processors
>> were known to run very hot and were subjected to this for many years
>> indeed. So a short-term test does not give the whole story.
>>
>>
>> --
>> Dr. David Kirkby,
>> G8WRB
>>
>> Please check out http://www.g8wrb.org/
>> of if you live in Essex http://www.southminster-branch-line.org.uk/
>>
>>
>>
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>>
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>>
>
>
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