I for one, highly recommend a trip to W4RNL's web site and read
his articles on quads. He presents quite a bit of useful
information about this subject.
Ed W3NR
2/5/02 9:38:16 AM, "Brown, James E LRDOR"
<James.E.Brown@lrdor.usace.army.mil> wrote:
>
>How would the receiving capabilities of this antenna be
effected, if at all,
>by having the one feedline as opposed to separate feedlines?
>
>Jim W4LC
>
>In a message dated 2/2/02 6:23:59 PM Pacific Standard Time,
ROBKEL@aol.com
>writes:
>
>> I have recently put together a 2 element triband quad. 20 & 15
M work
>good,
>> with a under 2.0:1 over full band (<1.4 over most).
>> 10m VSWR is unacceptably high (3:1 or so over full band.
>> I have checked all connections and dimensions, all OK. Feed
is a single
>feed
>>
>> line through a balun and then a length of 75 ohm twinlead to
a common
>> connection of all three bands.
>> I arranged to isolate just the 10 m DE, and it shows a 2:1
VSWR over
>band.
>> I was under the impression such antennas were common an
presented a good
>> match on all bands. I plan to test the balun soon, and also
considering
>a
>> 2:1 W2FMI transformer.
>
> You'll have problems when you feed a quad with the
feedpoints tied
>together and using one feedline; the 20M loop will radiate when
you're on
>10M
>(14 & 28 mHz). Use 3 feedlines and your problems should be
minimized.
>
>Cheers,
>Steve K7LXC
>Tower Tech
>
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________________________________________________________________________
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