Topband: two wires Beverage

[Joe Subich, K4IK]

Jacques, 


> Rys want to use this twested military telephone line for a 
> two wire beverage, I agree Jim, on  one direction the impedance 
> between the two wires and the ground will be more or less the 
> same as with any other type of wire but Rys want to use also 
> the 150 ohms twisted line to return the signal from the far
> end to make a reversible Beverege.

Other than the possible impedance change with weather that W8JI 
warns about, you should not have any problem using the 150 Ohm 
line for a reversible beverage as long as you adjust the 
transformers for the new impedance ratios.  

If you look at ON4UN's book, figure 7-23 on page 7-22, it will 
be necessary to adjust n1:n2 of T5a to a ratio of 1:1.75 (or 
the square root of 450/150).  You will also want to adjust the 
ratio of n1:n2 in T4 to 1.75:1 (in this case the square root 
of 150/50). 

In a normal two wire Beverege, T5A would have a ratio of about 
1:1 (450:450) and T4 would have a ratio of 3:1 (Square root of 
450/50).  

The transformation ratio in T1 will not change with the impedance 
of the two wire line as it is looking at "Beverage mode" to 
receive feedline (450:50). 

73, 

   ... Joe, K4IK