I'm rebuilding a db-252 corner reflector for use on 2 meters. The 
original (broken) dipole radiator was fed with a 36 inch piece of 
the "vapor block" db feedline. I think this stuff is 70 or 75 ohms, 
judging by the center conductor diameter. It's pretty much identical 
to RG-11 (75 ohm) cable. The question is, how do they calculate the 
length of the matching section? 36 inches is a physical half wave 
(not electrical length) at the original center frequency of 155 mhz. 
I guess I could just replace it with the same length, but I was 
thinking that it needed to be a tad longer for use at 147 mhz. 
Whadda ya'll think? I'm really just guessing at the 70 ohm 
impedance, but a straight dipole *is* 75 ohms, isn't it?

Thanks in advance...

na6df..  dave








 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/Repeater-Builder/

<*> To unsubscribe from this group, send an email to:
    [EMAIL PROTECTED]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 



Reply via email to