great thanks butch.
73
Colin, V A6BKX
----- Original Message -----
From: "Butch Bussen" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, August 05, 2005 10:08 AM
Subject: Re: Ts 480 and power supply


> Let me see if I can remember this.  It is basically an impedence match, so
> a two to one would mean the  impedance is 50 ohms over 25 ohhms reverse or
> 100 ohms over 50 ohms.  Now, let us say we are reading the power in watts
> and we want to calculate the swr.  I wrote a program to do this once.  Let
> us say you read 100 watts forward and ten watts reflected.  As I recall,
> you take square root of forward plus square root of reflected and divide
> this answer by square root of forward minus square root of reflected.  So,
> in this example, suqare forward is ten, and square root of ten is 3.16, so
> we add 10 plus 3.16 twhich is 13.16.  Now take ten minus 3.16 which is
> 6.84.    Now the final step is 13.16 over 6.84 equals 1.923, so the wr is
> 1.923 to one.
>
> Hope this makes sense.  As I said in an earlier post, 1.5 is aprox 6
> percent and two to 1 is 11 percent.
> 73s
> Butch Bussen
> wa0vjr
>