[AMPS] Hi Power Connectors

[Tom Rauch]

Hi Ian,

> The term "UHF" is a complete misnomer in discussing these connectors. They
> are strictly HF devices. VSR above around 140 MHz is too high. The better
> types use PTFE, bakelite or similar insulation (won't melt when heated
> with a soldering iron).

The impedance bump in a UHF connector is confined entirely to 
the area of the female about 1/2 inch long, assuming a hood is 
used on the female's rear. The impedance of that bump  is about 
30-35 ohms.

The VSWR error from using a single connector, assuming the 30 
ohm impedance and a VP of .5  is 1.028:1 at 50 MHz. 

It is only 1.25 at 400 MHz!

That's why you find UHF connectors used on landmobile radios up 
to 400 MHz and higher. The impedance bump, and loss, of a UHF 
connector can be pretty much ignored up to 250 MHz, and often is 
negligible above 250 MHz if the connector has partial air dielectric 
in the female section.


73, Tom W8JI
w8ji@contesting.com

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