[Amps] insulation

[R.Measures]

>
>>
>>The opposite example is that I once used Delrin for the PA tuning shaft in 
>>a little 6522 2m transmitter. The capacitor rotor was *supposed* to be at 
>>RF ground, and that TX couldn't have been putting out more than 25W, tops 
>>- but the Delrin melted in seconds. Wrong place, I guess.
>
>Hi, Ian--
>
>Are you SURE that the material was Delrin?  Sure sounds like NYLON
>to me.  I have been using Delrin as the form for the plate RF choke on
>my 3CPX5000A7 amps at 49 MHz.   These run 50-100 KW pulse and
>2 or 3 KW average and often transmit for WEEKS at a time--in some
>cases for YEARS.  I have NEVER had a failure of a Delrin RF choke
>or ANY hint of any heating.  I have been building these amps--at
>least 100 in the field--for the past 20 years and not one single problem
>with Delrin as the RF choke form.
>
>So I am quite surprised with your results--to the point of believing
>that it was probably NOT Delrin.
>
•  Sure, Delrin® has a lower D-factor than Nylon, but it is still 
substantial.  The styrenes and polyethylenes are way better around RF.