[TowerTalk] Right Angle Connectors

[Roger (K8RI) on TT]

 From Jim's post it could be Delrin. I'll know when I give it the heat 
test.  I have a number of 1" Delrin rods about a foot long, but they arr 
not white, but rather an off color that is close to white but would 
never be mistaken for white.  When working as a tech, I made a number of 
low speed bearing out of it in an attempt to reduce vibration in float 
zone refiners. IIRC  It doesn't cold flow like Teflon, but that was well 
before 84. Probably in the late 60s or early 70s.

73

Roger  (K8RI)


On 5/7/2016 Saturday 11:54 AM, jimlux wrote:
> On 5/7/16 7:01 AM, Richard (Rick) Karlquist wrote:
>> On 5/6/2016 6:36 PM, Don W7WLL wrote:
>>>
>>> After reading specs that the Amphenol used PTFE
>>  (all of my Amphenol of a later vintage appear to be clear insulation)
>>> Don T
>>
>> Where did you read that Amphenol used PTFE?
>> I have never heard of that.
>> BTW, PTFE is never clear, AFAIK.
>>
>
> PTFE is usually a solid white
>
> a sort of translucent clear is often polyethylene (or high density PE) 
> - low melting point, but no halogens, so burning it is like burning 
> wax, you'll see this in "plenum rated" cables, because it doesn't 
> create a toxic smoke hazard when a building catches fire
>
> Phenolic - a thermoset plastic (e.g. Bakelite, it's been around for 
> over a century) which usually has a filler (wood in the case of 
> Bakelite). I've seen UHF connectors with a phenolic fabric dielectric 
> (you can see the weave), it's probably linen for the fabric, since 
> that's what was used for "precision" components. Circuit board 
> material (XXP, for instance) used paper as the filler.
>
> Diallyl Pthalate is a popular dielectric - it's rugged, but I don't 
> know if it's used much in RF connectors - typically it's blue or 
> green, in connectors like Submini D.  It's also used in high voltage 
> connectors.
>
> Connectors which use phenolic often have an "upgraded" version using 
> Diallyl Pthalate.
>
>
> There's been changes in manufacturing since the UHF connector was 
> introduced pre WW-2
>
> https://www.google.com/patents/US2422982
> https://www.google.com/patents/US2335041
>
>
> Back then, you'd machine stuff and assemble it.
> Now, injection molding and form in place might be more common - it's a 
> LOT cheaper.
> PE is trivially injection molded - Phenolic is "machine and assemble"
> PTFE can be sort of molded: they sinter a powder in a mold, but you 
> can't injection mold it.
>
>
>
>> In any event, PTFE is greatly inferior
>> mechanically, and has no electrical
>> advantage at HF, or even UHF.  It's
>> high temperature rating is also of no
>> consequence for most ham applications.  I
>> don't know why any knowledgeable person
>> would even want it, except in some
>> corner case like a common mode choke
>> made with PTFE coax.
>>
>> Rick N6RK
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>>
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-- 

73

Roger (K8RI)


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