R. Measures wrote:
> <snip>
> Even though it is excellent around RF, the trouble with TFE is that it
> cold-flows and it has little strength. .
> For strength, RF-tolerance and workability, G-10 is hard to beat.
>
I agree and MSC carries G10 rod, tube and sheet. It's found on page 1794
of their big book: <http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=1794>
A 48" length of 3/8" rod lists for $12.08 so 48x2=96-4(2" for cuts)=92
and 12.08/92=0.131 so $0.13 for John's insulators. Still a great deal.
I love ceramic but there are much less cost alternatives out there that
work fine. The 1/2" rod lists for $19.42 in a 48" length and 1" rod
lists for $54.93. 73, Tony W4ZT
>> A 12" length that is 3/8" in diameter
>> lists for $3.59. That looks like 3.59/22= $0.16 each! Not bad for an
>> insulator that you don't have to worry about (I allowed an inch for
>> waste in saw cuts). They also carry fiberglass rods, tubes and sheets,
>> micarta, silicon rubber and many other useful items.
>>
>> Look here: <http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=1790>
>> Their home page is <http://mscdirect.com>
>>
>> MSC is a good outfit to deal with. They have a GREAT on line catalog
>> and can deliver almost anything you can imagine in the way of hardware,
>> materials and tools. I use them all the time and highly recommend them.
>>
>> 73, Tony W4ZT
>>
>>
>> Tomm Aldridge wrote:
>>
>>> John,
>>>
>>> In my opinion, the use of Nylon for general standoffs in an RF
>>> amplifier
>>> is perfectly fine if a bit of thought is given as to the temperatuer
>>> they will be exposed to. I would not consider Nylon for a tank or
>>> plate
>>> coil former nor for the building of capacitors (as a dielectric). I
>>> use
>>> a machined Nylon couple between my two roller inductors in my balanced
>>> tuner and have seen no issues there. Supporting your plate coil on
>>> Nylon would not be advised due to both RF fields and high temperature.
>>> Instead of ceramic standoffs consider G-10 glass reinforced epoxy
>>> stock.
>>> You can get it from McMaster Carr in a variety of shapes, including
>>> tubes suitable for coil winding.
>>>
>>> Tomm, KD7QAE
>>> going down in frequency since 1975...10GHz >>> 1.8MHz
>>>
>>> John Irwin wrote:
>>>
>>>
>>>> I made the original inquiry about the nylon I found at the ace
>>>> hardware store . These little cylinders are the same size,shape as
>>>> ceramic standoff insulators commonly used in amplifiers. I was
>>>> looking for a low cost replacement for ceramic standoff insulators
>>>> made expensive by the "PARTS MERCENARIES" that seem to have
>>>> infected our hobby today.
>>>> It is likely I will fork over to get ceramic as I don't want to
>>>> take chances, with nylon melting ,softening. or crystallizing. What
>>>> with big bangs,kapow,parasitics, spark gaps and other problems. I
>>>> will play it safe. Nylon goes back to ace. what about glass?
>>>>
>>>> Nylon cylinders cost a quarter. ceramic, well a lot more.
>>>>
>>>> anyone know of a low cost source for ceramic standoff
>>>> insulators,3/8" diameter,length 1/2" or something similar.
>>>>
>>>> john kb9tc
>>>>
>
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