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A99 higher SWR in CB band, but not in 'C' band
- Thread starter mr_fx
- Start date
ok,.... I'll play for a while,..............
soo,..... he says to feed with EVEN multiples of 1/2 wl, (1/2, 1, 1 1/2) wl ect..............
what happens when you feed with ODD 1/4 wl ( 1/4, 3/4, 1 1/4 wl, ect) mults?
ok i just got off the phone with mark and he said theres no difference unless its phazed against anothe rarray and needs to iether at 0 degrees or 180 for a spacific pattern
no difference if fed from a even 1/4 wl mult VS fed from a odd mult??????????????????????????????????????????????
if Mark is your RF engineer, then he needs to hit the books
NO! You're still in -that- group unless you paint the whole mess pink!
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What's the difference between even numbers of a 1/4ws and an odd number of them? Oh, about a 1/4 w length. No matter how long the thing is in feet.
- 'Doc
yepper,................ and a few details concerning feeding antennas from voltage loops as opposed to current loops with tuned feedlines.:blink:
no difference if fed from a even 1/4 wl mult VS fed from a odd mult??????????????????????????????????????????????
if Mark is your RF engineer, then he needs to hit the books
Oh now i see what you were saying. it was the capitol VS that confused me. no i was talking about 1/2 waves not 5/8 or 1/4 or 1/16 or 93/467ths. i was talking about electrical half wave multiples of coax. i dont know where you got the 1/4 wave from. an odd multiple of a 1/4 wave acts as a impedence matching transformer. that much i know
and just so people dont go off on the 18 foot thing again its 18 feet times the velocity factor for an electrical 1/2 wave not 18 feet of coax and its 18 feet times the vf for cb not ham, not 10m or 20m or 160m but cb like this topic is about
edit- ok i went back and read your post about the 1/4 wave thing. i dont remember reading anything about 1/4 waves before so i guess i missed it. my bad.
i was olny talking to mark aboyut 1/2 waves like the rest of my posts and didn't see your 1/4 wave question. sorry:blushing:
this flu is kicking my ass. my excuse:blush:
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yeah, the flu can sux
the reason I mentioned that was because most people seemed to be missing WHY a "tuned" feedline would be used,.... no, it's really not because the SWR meter will repeat the feedpoint SWR (although it will if even 1/4 wl mults are used).
the real reason is to control feeding the antenna from a VOLTAGE loop instead of a CURRENT loop, (or somewhere in between the two.)
you want the voltage to be MAX, and the current to be MIN at the feedpoint (even 1/4 wl's) instead of current max and voltage min (odd 1/4 wl's)
good info there.yeah, the flu can sux
the reason I mentioned that was because most people seemed to be missing WHY a "tuned" feedline would be used,.... no, it's really not because the SWR meter will repeat the feedpoint SWR (although it will if even 1/4 wl mults are used).
the real reason is to control feeding the antenna from a VOLTAGE loop instead of a CURRENT loop, (or somewhere in between the two.)
you want the voltage to be MAX, and the current to be MIN at the feedpoint (even 1/4 wl's) instead of current max and voltage min (odd 1/4 wl's)
is it a voltage loop or node or maxum?