[TowerTalk] Cable Window entry

[Jim Pruitt]

I am hoping that someone(s) can give me some advice on cable window 
entries.  I am looking for something like a 1/4" thick aluminum strip to 
go in the window track.  The tracks are 38.5 inches apart. I was unable 
to find a 4 inch wide aluminum flat bar strip at a reasonable price ($40 
for the strip and $40 for shipping).  I did find a 3 inch wide strip and 
do have that. What I want to know is what length I need to cut it to.  
If I make it the full 38.5 inches long then how do I get it into the 
tracks since I can't slide it in from the end?  If I cut it to say 38 
inches then what do I use to fill the other 1/2 inch (or 1/4 inch on 
each end)?  Do I just use stick on weather stripping?

The second part is, how do I make the D shaped holes for the SO239 
bulkhead feedthroughs or the UG492 BNC bulkhead feedthroughs?  I am sure 
my 5/8" Greelee punches will not even make a dent in the strip.  I do 
not have access to a vertical mill to cut the holes.

Thank you for your help.

Jim Pruitt
WA7DUY