[TowerTalk] Polyamide (Stauff) Insulator Clamps

[john at kk9a.com]

My 40m OptiBeams use black clamps, I am not sure of the manufacture  
but they look like Stauff clamps.  I wonder who is saying that the  
black clamps have a carbon issue?  Can you buy one and test it?

John KK9A



Byron W5FH wrote:

Hello-    I am a little confused about the UV and electrical  
properties of the polyamide insulator clamps (hydraulic and tubing  
line support clamps) used on the VHF LFA yagis. I have viewed  
commercially produced VHF LFA yagis that utilized green colored ones  
to support 13mm tubing elements. I have read the black ones are better  
in regards to UV resistance. However, some antenna manufacturers state  
the black colored clamps have additional carbon in them and the  
antenna element lengths will need adjusting.    My head is nearly  
spinning after trying to research this. I have tried to look through  
the thousands of polyamide clamps in the Stauff catalog. Can anyone  
shed any light on whether the green colored polyamide clamps, such as  
used on an E-Antenna 6 meter 7 element LFA yagi, are inferior in  
regards to UV resistance? I see where a competitor (making mostly HF  
yagis) states the black clamp assemblies they use are better in  
regards to UV resistance of the green ones that E-Antenna uses, but I  
wonder if the black clamps have identical electrical properties or  
would corrections need to be made to elements? I see where G0KSC, an  
authority on the LFA and their construction, offers the green colored  
clamps.   Thanks,   Byron W5FH