When you start trying to diddle with using an antenna
like the multi dipole arrays out of band, the beam-width,
down-tilt and other major performance issues start to get
a little squirlly'
The results for the same antenna installed at different
elevations above average ground hight (agl) might be heaven
or purgatory. Purgatory costs serious money and time to fix
unless you have a special hot-line to the "Antenna Pope".
> Mathew Quaife <[EMAIL PROTECTED]> wrote:
> My unmodified DB224 had a VSWR of 1.8:1 in the 147 Mhz portion of 2
meters, in the 145 Mhz portion it went over 2.1:1. After the
modifications it went down to 1.6:1 at 145 Mhz. On the receive
portion I did not notice any changes, in the transmit, it did improve
the power output, as expected. It depends on where you are getting
the antenna from, as there has been talk that only the harness was
being changed. There is some messages here on the board about
modifiying a DB224 and leaving the harness as is. I have a DB304 that
I am going to expierment with and see if it works. Look back over the
last few weeks of messages and you will see there is a link in one of
them that pointed to the modifications.
> If you can get the antenna that has the extended elements, and is
true for the 138-150 Mhz band, then that would be the antenna to
purchase. Ask them to measure the elements, and if I remember right,
they came out to 37 1/4". I've been also told by some that they think
it was 39", someone on the list might be able to confirm this.
> Don't get one that has just the harness modified, as it will look
good on your frequency, but then does not have a ver wide spread, mine
only went about 1.5 meg and the VSWR rose drastically, very noticably.
At my freq that I had it cut for, it is at 1.2:1, but move just one
meg and it went to 1.8:1. Just how mine turned out. Hope this helps.
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