RadioBanter

RadioBanter (https://www.radiobanter.com/)
-   Antenna (https://www.radiobanter.com/antenna/)
-   -   2 Mtr Beam Question (https://www.radiobanter.com/antenna/100973-2-mtr-beam-question.html)

N3 August 9th 06 01:38 PM

2 Mtr Beam Question
 
I'm trying to tune a 2 mtr, 3 element beam that has a gamma match.
After connecting the coax to the driven element & adjusting the
matching unit, where should the coax exit in relation to the boom & the
elements? Should it travel along the boom or drop straight down next to
the driven
element? Any assistance concerning the above would be most appreciated.
Thank You.


Buck August 9th 06 01:45 PM

2 Mtr Beam Question
 
On 9 Aug 2006 05:38:48 -0700, "N3" wrote:

I'm trying to tune a 2 mtr, 3 element beam that has a gamma match.
After connecting the coax to the driven element & adjusting the
matching unit, where should the coax exit in relation to the boom & the
elements? Should it travel along the boom or drop straight down next to
the driven
element? Any assistance concerning the above would be most appreciated.
Thank You.



I have always run mine below the boom to the mast and then down the
mast, into a drip loop and below the rotor, making sure there is
enough room to turn the rotor without stretching the coax out of the
drip loop.

Buck
N4PGW

--
73 for now
Buck
N4PGW

N3 August 9th 06 02:05 PM

2 Mtr Beam Question
 

Buck wrote:
On 9 Aug 2006 05:38:48 -0700, "N3" wrote:

I'm trying to tune a 2 mtr, 3 element beam that has a gamma match.
After connecting the coax to the driven element & adjusting the
matching unit, where should the coax exit in relation to the boom & the
elements? Should it travel along the boom or drop straight down next to
the driven
element? Any assistance concerning the above would be most appreciated.
Thank You.



I have always run mine below the boom to the mast and then down the
mast, into a drip loop and below the rotor, making sure there is
enough room to turn the rotor without stretching the coax out of the
drip loop.

Buck
N4PGW



I forgot to mention that this antenna is being used for 2 mtr FM. If i
drop the coax down vertically it will touch the driven element as well
as the matching unit.
--
73 for now
Buck
N4PGW



Owen Duffy August 10th 06 12:17 AM

2 Mtr Beam Question
 
On 9 Aug 2006 05:38:48 -0700, "N3" wrote:

I'm trying to tune a 2 mtr, 3 element beam that has a gamma match.
After connecting the coax to the driven element & adjusting the
matching unit, where should the coax exit in relation to the boom & the
elements? Should it travel along the boom or drop straight down next to
the driven
element? Any assistance concerning the above would be most appreciated.
Thank You.


Your description is not entirely clear, but I interpret it to mean you
have a vertical beam. In that case you should not have any additional
vertical conductor within about 0.2 wavelengths to the rear of the
beam, or anywhere within, near, or in front of the beam.

So... if that is the case, you could route the cable from the
feedpoint, back along the boom, and continue in that direction for a
further quarter wave or more before dropping the cable down.

There are other ways to get the cable away without disturbing the
pattern and feed point impedance.

Owen
--

Buck August 10th 06 03:12 AM

2 Mtr Beam Question
 
On 9 Aug 2006 06:05:44 -0700, "N3" wrote:


Buck wrote:
On 9 Aug 2006 05:38:48 -0700, "N3" wrote:

I'm trying to tune a 2 mtr, 3 element beam that has a gamma match.
After connecting the coax to the driven element & adjusting the
matching unit, where should the coax exit in relation to the boom & the
elements? Should it travel along the boom or drop straight down next to
the driven
element? Any assistance concerning the above would be most appreciated.
Thank You.



I have always run mine below the boom to the mast and then down the
mast, into a drip loop and below the rotor, making sure there is
enough room to turn the rotor without stretching the coax out of the
drip loop.

Buck
N4PGW



I forgot to mention that this antenna is being used for 2 mtr FM. If i
drop the coax down vertically it will touch the driven element as well
as the matching unit.
--
73 for now
Buck
N4PGW


Drop it down the mast on the opposite side of the antenna element. I
know some element(s) are probably near the pole, but to one side of
it, but put the coax on the opposite side of the pole. There should
be no further interference with the signal than the pole already
offers.

Buck

--
73 for now
Buck
N4PGW


All times are GMT +1. The time now is 06:56 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
RadioBanter.com