[BC] "VSWR" Metering

[Cowboy]

On Sunday 16 October 2005 05:52 pm, cld at admin.umass.edu wrote:
>
>These have been great and informative comments. Thank you gentlemen. May I 
>boil it down to "a vswr meter is valuable for viewing the antenna system match 
>to the transmitter in general (for those of us without access to a TDR), but a 
>good vswr indication should not be taken as gospel truth that there isn't a 
>mismatch somewhere"?

 I'll take that.

>Which brings us to the next question- if indeed you see a "good" reflected 
>power indication at the tx output, but still suspect something is awry, what, 
>in your opinions, are the best places to look (and let's say that you don't 
>have the ability to climb a tower and check the vswr at different points nor 
>have access to a TDR). Efficiency? 

 I'd look first at transmitter loading.

 Next, add 1/4 wave of line between the meter and the load, and read
 it again.
 Ignoring the absolute value of the numbers, the important question
 is whether or not you see a change.

 Efficiency is not valid, as the transmitter may well show the same as long
 as it's delivering the same power, whether into a good load, or a fire.

-- 
Cowboy

http://cowboys.homeip.net

"It's not Camelot, but it's not Cleveland, either."
		-- Kevin White, mayor of Boston