[Amps] Power handling of an SMA

[Roger (sub1)]

On 4/27/2011 3:20 AM, Steve Thompson wrote:
> I found big differences in N type socket construction where the
> centre contact is captive (mostly 4 hole or bulkhead sockets).
> With Amphenol, for example, the pin has a bit of knurling to lock
> it into the PTFE. The pin pulls out quite easily which is great
> for making small sections of air line where getting in to solder
> in situ would be difficult

It's also one of the weaknesses of N-type connectors on long vertical 
runs as the center pin tends to pull back and lose connection with the 
female connector.  This is quite common with those long vertical runs.

> - but it's not strong with flexing. The
> old UK Greenpar brand (now part of MA/Com Tyco) have a tophat
> ferrule on the pin with the PTFE moulded around it - noticably
> stiffer and impossible to remove without destroying the connector.
>

One of the reasons I used to dump some Vinyl ester resin mix into the 
N-type connectors.  That rendered them impossible to reuse, but I never 
had one come apart of suffer from center pin migration. <:-))  I did the 
resin treatment for all "clamp type" N-Connectors.

I'd like to change over to 7-16 DIN if I could find a bunch at a 
reasonable cost.  With nearly a 100 connectors that would need changing 
I'd mot likely be looking at more than two grand just for connectors.
Course I'd like to find at least to 7/8" Heliax from the stations to the 
6-pack and from the 6-pack to the antennas for VHF, UHF, and 160 meters. 
with 7-16 DIN connectors.

Coax from  the rigs to the top of the 45 G are roughly 228' long and 
from the den to the top of the 25G (or crank up eventually) for the 
tribander and WARC 7 are close to 300 feet.  I'd like to put a 
quadrature array for both 144 and 440 on that with elevation as well.

OF course, "would like to" and "will" may be quite different when it 
comes to the actual implementation.


73

Roger (K8RI)
> The centre pins on sockets vary too. My beloved Suhner has a
> design with 6 tiny slots forming the tulip rather than the 4 wider
> spaced springs on most. I don't know if it makes a big difference
> with contact resistance or reliability, but it sure looks a whole
> lot nicer.
>
> It's a shame C types didn't become more popular - they combine
> many of the best bits of 259 and N; constant impedance, sealing,
> big centre pin.
>
> Steve
>
>> The other (huge) thing not being mentioned is weatherproofing.
>>
>> I have both weatherproof and non, and the diff in price between flavors is nil:
>>   ie, REAL weatherproof PL259s are the same price as their N and BNC
>> counterparts.
>>
>> The PL\SO239 connector is SO MUCH MORE healthy, though.  I converted a 10 meter
>> vertical to N connectors before I discovered weatherproofPL\SOs.  I get 3
>> inches of ice, and over 100 MPH winds here.  Weatherproofing is a BIG deal.
>>
>> The N males failed 3 times in 1 winter.  The center socket wriggled around from
>> having the gamma direct mounted and would hollow out.  The SO239 I'd replaced
>> had been in 3 complete winters here, and was over 30 years old.  I put it back
>> after the 3rd N failure, gorilla snotted the SO connector, and used gasketed
>> PL259s since.  NO more problems since.
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