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Old August 13th 07, 05:45 AM posted to rec.radio.amateur.antenna
Sal M. Onella Sal M. Onella is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 442
Default Two Good Days Spent with Quads

[After sending this, I never saw it posted so I re-sent. Sorry if it's a
dupe in your newsreader.]

"John Ferrell" wrote in message
...



Don't overlook that you can parallel two quads to get to 50 ohms as
well!



OK, I took a mental excursion in that direction. My first thought is to use
two runs of RG-62 93-ohm computer drop cable off a t-connector. This goes
against my grain -- I've always hated using any t-connectors in a matched
system -- but I guess the match will be maintained.

My second thought is to literally parallel them at the end of a hunk of
50-ohm cable. That feed would need to be crossed over, I think, so the
fields would be additive. Easy enough to test it both ways, I suppose. If
crossover is needed, what would the pattern look like without it? Hm-m-m-m
.... near-field cancellation and no pattern? Pattern rotation?

Of course I will be trying this next idea even if no newsgroup answer is
forthcoming: What happens if I tap off quad #1 on the side _opposite_
where I'm feeding it and connect quad #2 there? Wouldn't this additional
load reflect back to feed #1 and lower its impedance toward 50 ohms? I
don't know what feed #2 would be. Perhaps a jury-rig parallel line
calculated to be 100 ohms would do it. (# 10 AWG wires on 5 mm centers would
do it.) Phasing will be an issue.
[I probably don't have a suitable test environment to tell success from
failure.]

73,
"Sal"