[R-390] r-390A ballanced/unbal mod. ?

[rbethman]

The balanced connection has connectors out there, NOT cheap, that will 
take regular coax to connect.

This feeds all stages.

*IF* you use the balanced connector to insert your signal for alignment, 
assuming the signal generator is terminated/designed for 50 ohm output, 
then the radio WILL behave as though it has a 50 ohm feed.

So now you have a few more pieces of the puzzle.

The same could be said by injecting the same connector with a 75 ohm signal.

Bob - N0DGN

On 5/23/2013 1:45 PM, Dave Sampson wrote:
> hello
>
> first ...thanks for all your input on painting and line voltage dropping.
>
>
> there is an r-390/A field change which re-routes internal coax connections so that the unballanced connector will make use of all of the rf stages and a mod for the ballanced connector that uses an impedance matching balun and a twinax to single conductor connector.
> so....if you swap the internal coax connections to bring all the rf stages to the unbalanced connector, (is there stil an impedance missmatch which requires a ballun?)
>
> thanks
> 73s
> dave
>