On Mon, 15 Feb 1999 00:18:09 +0000 "Ian White, G3SEK"
<G3SEK@ifwtech.demon.co.uk> writes:
>
>Carl wrote:
>>
>>
>>
>>On Sun, 14 Feb 1999 11:28:09 +0000 "Ian White, G3SEK"
>><G3SEK@ifwtech.demon.co.uk> writes:
>>
>>SNIP
>>>
>>>In the end, the only way to find out is to try it. For situations
>>>where
>>>an inexpensive and easily machined material such as Delrin is proved
>
>>>to
>>>work, there's no point in paying for PTFE or ceramic.
>>
>>B&W initially used ceramic forms for their 802 plate RFC. As a cost
>>reduction they went to Delrin. I have several failed Delrin RFC's
>here
>>that all failed at the tube end only which makes me believe it was a
>RF
>>related failure, not DC or straight IR losses.
>
>Fair enough - anything involving high RF potentials (and probably
>high
>temperatures too) is a risky application that would need careful
>testing
>before committing to production. It's more difficult for component
>manufacturers such as B&W and the roller coil makers because they
>can't
>anticipate all future uses.
>
>It then comes back to the equipment manufacturers to test their
>products
>well beyond the claimed ratings... but then the marketing droids want
>to
>market the products at the test ratings! Finally the end users push
>the
>products harder still, and sure enough, they fail.
>
>>Soft Teflon makes a poor choke form but hard Teflon works quite well.
>I
>>believe it has a fiberglass mixture. Machines well and costs less
>than
>>pure Teflon.
>
>Any brand names and sources?
Ian,
IPM is one mfg and available locally from Plastics Supply Corp which I
believe is USA wide.
There are probably several others that stock but today is a holiday and
I've been unable to get more info sofar. Perhaps others have additional
info.
The correct nomenclature is " glass filled Teflon".
73 Carl KM1H
>
>73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
> 'In Practice' columnist for RadCom (RSGB)
> http://www.ifwtech.demon.co.uk/g3sek
>
>--
>FAQ on WWW: http://www.contesting.com/ampfaq.html
>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
>Search: http://www.contesting.com/km9p/search.htm
>
>
___________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com/getjuno.html
or call Juno at (800) 654-JUNO [654-5866]
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|