Fw: [Antennas] 5-Band Quad VSWR

[Walter J. Slazyk]

I am new to the reflector and might have messed up on protocol. Am I
supposed to cc the reflector on these replies to keep the string going?
----- Original Message -----
From: "Walter J. Slazyk" <kf2xn@adelphia.net>
To: <W3HKK@aol.com>
Sent: Thursday, January 02, 2003 08:28
Subject: Re: [Antennas] 5-Band Quad VSWR


> Hi Bob,
> Thanks for the comments. Regarding your question, I called Mike Duddy at
> Lightning Bolt Antennas so many times on this issue, by now, he must be
> thinking that I am some kind of "anal perfectionist" (which I may very
well
> be, in somebody's opinion, hihi). He advised me to test the balun by
placing
> a 100 ohm resistor across the terminals of the balun and take a reading
with
> my trusty MFJ-259B.  It showed a perfect match for a 50 ohm feed line. I
> tested my PL-259's and the brand new 150' run of LMR-400 coax with a
> cantenna dummy load at the end and it too, checked out with a slightly
> higher than 1:1 reading which I must presume has something to do with the
> coax length and/or velocity factor.  I have yet to fool around by trimming
> the wire loop element lengths because it is impossible to lengthen the
loops
> once shortened due to the type of wire material used in LB Quads. I also
> tried varying the spacing of the driven element: i.e. moved closer to the
> reflector in one experiment, moved closer to the directors in the other
> experiment - both showed no significant changes. One thing that Mike
> suggested was that there might be RF coupling going on. I wound a section
of
> RG-213 into 5 one-foot turns and placed several ferrite split beads after
> the loop. In one experiment, I placed this RF Choke right after the balun
at
> the quad's feed point. No change. I then reversed the length in an attempt
> to place the RF Choke directly below the RF field of the quad elements and
> the SWR improved somewhat. It is still way out there in the ozone compared
> to what it was before I went to 4-elements. One thing I should mention
> before we get too far into this subject is that I live very near (line of
> sight) to 2 major TV Station broadcast towers. I went to Radio Shack and
> purchased that nifty little wireless video camera detector which detects
the
> RF. Sure enough, at certain times of the day or should I say night, this
> thing beeps like crazy when placed in the direction of the broadcast
towers.
> In any event, I read somewhere that the presence of a strong RF field may
> tend to "confuse" small handheld type SWR analyzers because it may see the
> RF as reflected power. This may account for inconsistent SWR readings from
> time to time?
> I must also mention that on 12 and 15 meters, the SWR and bandwidth for
most
> of the band is 1.2:1 across most of the band. I noticed a pulsing on the
> meter of the MFJ-259B analyzer from time to time. Could this be the
problem?
> What do you think?
> 73 Walt
> KF2XN
> ----- Original Message -----
> From: <W3HKK@aol.com>
> To: <kf2xn@adelphia.net>
> Sent: Thursday, January 02, 2003 06:47
> Subject: Re: [Antennas] 5-Band Quad VSWR
>
>
> > What does the manufacturer say?
> >
> > When I converted my very wide bandwidth KT-34  triband yagi to the  4
> element
> > long boom ( 32 ft) special, the bandwidth did narrow down especially on
> > 10M...but the swr was very low over most of the phone band on all three
> > bands.    The  advice KLM provided was however virtually identical to
the
> > actual  installed results....and the antenna performed like
> gangbustes....tho
> > I never needed   a tuner.
> >
> > Usually a high swr indicates that the  front to back and forward gain
have
> > also gone to pot,
> >
> > -What does the manufacturer say about your results?
> > -What is the bandwidth at swrs of 1.5:1 and below on each band?
> >
> > Bob
> >
> > PS  at the next qth ( one tha permits outside antennas) I intend to go
> with a
> > 5 band   2 el. quad....as most bang for the buck. Had to sell off my
> > tower/yagis when I moved here 6 yrs ago.
> >
>