On Mon, 27 Sep 2004 10:20:54 +0200, Toni
wrote:

En Tempest va escriure en Mon, 27 Sep 2004 04:12:17 GMT:

Lately I've been using this little "high gain" antenna that my company
uses in poor reception areas to boost the signal strength of these
little cellular data transmitters we use in our business.
...
A couple of days ago, I bought a Scantenna and I mounted it up on a
homemade mast. Here's a directory of pics I took while building it
all:

http://www.faradic.net/~sphynx/antenna

My little omni-directional 800 Mhz antenna is near the top of my roof
(not in the pictures).

The antenna you see in the pictures is probably 6ft below the highest
peak of my roof. I used every bit of the 50ft. of RG6U coax that came
with the Scantenna and only have the F-to-BNC adapter in-line.

With the Scantenna, the lower band reception seems to be much improved
over the smaller antenna I had been using before, but the reception is
the 800 - 900 Mhz range seems to be a little worse.
...
Are there any improvements I can make in my design? I was thinking of
elevating it another 6ft or so, but I'm forced to wonder if that would
really be of any significant benefit.
...
Any ideas would be appreciated. Thanks!

Hi,

If you are using 50 ft of cable from antenna to receiver try
replacing the antenna provided cable with other 75 ohm coax of
lower loss at 800 MHz. Use only good-brand cable with known
characteristics, don't rely on your local radio shop selling a
cable of unknown origin. Also use the right connectors of good
quality, without adapters. This should not be very expensive to
try.

If your cable is already very-good (which I doubt) you will get
about equal. If your cable is not so good (likely) you can easily
gain several dBs (at 800MHz that is, below 300~400 MHz there
won't be much of a difference).


Thanks for the help, Toni.

I'm using the 50ft of RG-6U coax sent with the Scantenna. It has
F-conectors on each end, and the kit came with an F-to-BNC adapter.

What would you suggest specifically for cabling? I'm pretty new to
this.

Also, based on the pictures I posted, should I elevate the antenna
more? Typically how much of a benefit would I get out of maybe 6ft
more height?

Thanks