Outdoor Antenna Questions
 

Hello All, I've got some questions about outdoor antennas. I monitor a
motorola type II trunked system in Colorado Sprigns, CO.

I've got a 20-043 discone from RS, a uniden bcd396t, and 70 feet of
RG-6 quad-shield of cable inbetween. The antenna is on a mast 12 feet
in the air above the house.

Much of the radio communication is choppy; is that a artifact of how I
set up the system? Is this a good setup of cable/antenna/radio? I've
read some information about tuning antennas, but is that something I
still need to do in this case?

Thanks!

first check all connections
then get the ant up in the air 30 feet minimum about housetop
if you still have problems then cut coax run
70 feet coax for a 12 ft above house run.....
that's first place i would look
was coax new or used when you put it up


--
Don
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DUTY, HONOR, COUNTRY
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http://myweb.cableone.net/wxfreqrs/ Pascagoula Ms Real Time Observations
wrote in message
ups.com...
Hello All, I've got some questions about outdoor antennas. I monitor a
motorola type II trunked system in Colorado Sprigns, CO.

I've got a 20-043 discone from RS, a uniden bcd396t, and 70 feet of
RG-6 quad-shield of cable inbetween. The antenna is on a mast 12 feet
in the air above the house.

Much of the radio communication is choppy; is that a artifact of how I
set up the system? Is this a good setup of cable/antenna/radio? I've
read some information about tuning antennas, but is that something I
still need to do in this case?

Thanks!

I got another 6 feet, so it's about 20 feet in the air, and that was
it. I have a tin roof, and that might have been blocking when the
antenna was lower.

I also routed the coax around the eve of the roof to the office,
instead of through the garage to the basement up through the floor. It
might have had some interference in the basement.

I have one single run of coax, 70 feet, and I used compression bnc
fittings on both ends. I got the cable right off the spool at a local
home improvement store.

Thanks!

wrote:
Hello All, I've got some questions about outdoor antennas. I monitor
a motorola type II trunked system in Colorado Sprigns, CO.

I've got a 20-043 discone from RS, a uniden bcd396t, and 70 feet of
RG-6 quad-shield of cable inbetween. The antenna is on a mast 12 feet
in the air above the house.

Much of the radio communication is choppy; is that a artifact of how I
set up the system? Is this a good setup of cable/antenna/radio? I've
read some information about tuning antennas, but is that something I
still need to do in this case?

Thanks!

The distance and quality of the cable might well be the problem, i.e.,
signal loss. Also, anyone in CO with an antenna should take care with
lightning protection, metal roof or not.

You might consult www.strongsignals.net for estimating the signal loss
vs cable quality.

Oh I agree! I've got 6 gauge colid copper from the bottom of the mast
to an 8-ft ground stake (shared with house utilities). I still need to
find an inline supressor though for the coax.

Isn't RG6 coax 75 ohm TV cable? I think your scanner is designed to
take 50 ohm coax for optimum performance. Suggest you change the coax
to 50 ohm and if you have to use 70 feet, upgrade to something like
RG8/U or RG213.

Steve


wrote:
Hello All, I've got some questions about outdoor antennas. I monitor a
motorola type II trunked system in Colorado Sprigns, CO.

I've got a 20-043 discone from RS, a uniden bcd396t, and 70 feet of
RG-6 quad-shield of cable inbetween. The antenna is on a mast 12 feet
in the air above the house.

Much of the radio communication is choppy; is that a artifact of how I
set up the system? Is this a good setup of cable/antenna/radio? I've
read some information about tuning antennas, but is that something I
still need to do in this case?

Thanks!

In article . com,
says...
Isn't RG6 coax 75 ohm TV cable? I think your scanner is designed to
take 50 ohm coax for optimum performance. Suggest you change the coax
to 50 ohm and if you have to use 70 feet, upgrade to something like
RG8/U or RG213.

Steve


wrote:
Hello All, I've got some questions about outdoor antennas. I monitor a
motorola type II trunked system in Colorado Sprigns, CO.

I've got a 20-043 discone from RS, a uniden bcd396t, and 70 feet of
RG-6 quad-shield of cable inbetween. The antenna is on a mast 12 feet
in the air above the house.

Much of the radio communication is choppy; is that a artifact of how I
set up the system? Is this a good setup of cable/antenna/radio? I've
read some information about tuning antennas, but is that something I
still need to do in this case?

Thanks!



Again, it doesn't matter. No scanner is 50 ohms across hundreds of MHZ
anyway, and a 1.5 to 1 mismatch is nothing, especially on receive only.

BDK

I agree. Further to that, your RG8, RG213, or heaven forbid RG58, has
much more loss per unit length than a good quality RG6. Any signal lost
due to the 75ohm cable will be considerably less than the loss of the
other feedline.

Good quality RG6 makes fantastic scanner coax, but you have to be very
careful with your terminations and adaptors.



Again, it doesn't matter. No scanner is 50 ohms across hundreds of MHZ
anyway, and a 1.5 to 1 mismatch is nothing, especially on receive only.

BDK