[TowerTalk] Increasing power capability of 6-meter yagi

[Lux, Jim]

On 7/31/22 6:01 AM, Pete Smith N4ZR wrote:
> I have just bought a small Cushcraft 3-element 6-meter yagi.  Only 
> small fly in the ointment is that it is *only* rated at 1 KW.  It 
> looks to me that this limitation might relate to the feedline 
> connection, which is a bulkhead SO-239 (mounted with a big nut) 
> bracketed to the center of the driven element.
>
> My question is, do I need another connector here, or maybe insulation 
> between the bracket and the element?  If so, what material makes 
> sense?  Any other advice?
>
The rating might be derived from "only tested to 1kW"

But if it's design limited, it's either current at the feed point (Yagis 
often have very low feed point resistance, which is transformed up to 50 
ohms by the matching network, or by using a folded dipole at the feed) 
or voltage at the element tips (hard to model, usually validated by 
testing).

1kW into 20 ohms is 7 Amps - Easily handled by a UHF connector, but what 
does the rest look like?