[Antennas] Technical Question Re: Transmission Lines

[Chris Boone]

I would think as long as the Z of the different pieces are the same in each
line, you shouldn't have to worry...Velocity factor would affect you in a
phased array or similar situation but I don't think you have that situation
here....size should not be an issue unless the SWR is high at the antenna,
then you could possibly have a voltage/current issue in the smaller
sections. Of course, the loss in each piece will determine your overall loss
in each line..curious as to WHY the 3 bulkheads? Is there a way to make it
only one or none?
Chris
WB5ITT

> -----Original Message-----
> From: antennas-bounces at mailman.qth.net 
> [mailto:antennas-bounces at mailman.qth.net] On Behalf Of Dr M J 
> DiGirolamo
> Sent: Sunday, December 03, 2006 7:13 PM
> To: antennas at mailman.qth.net
> Subject: [Antennas] Technical Question Re: Transmission Lines
> 
> Dear Colleagues,
> 
>    From my shack to my antennas, the coax feed lines transition through 3
bulkheads.
> Hence, there are 4 separate coax pieces forming each antenna's path.
> 
>    Questions are as follows.  What effect, if any, does one 
> incur if the transmission lines in the sequence,
>  
>       a) have different velocity factors and/or
>       b) have different diameters.
> 
>     All the lines will all have the same impedance but 
> perhaps different losses/100' run.
> 
> 73,
> 
> Mike DiGiroalmo, W4XN