Two Discone Antenna's (at same time)

Status
Not open for further replies.

Saint

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
4,492
Location
Fort Erie Ontario Canada
I have two Discone antenna's, could I get better reception if I used a good splitter and ran both Discones at the same time if the were around 10 feet apart.
Steve
 

iMONITOR

Silent Key
Premium Subscriber
Joined
Sep 20, 2006
Messages
11,156
Location
S.E. Michigan
I have two Discone antenna's, could I get better reception if I used a good splitter and ran both Discones at the same time if the were around 10 feet apart.
Steve

I don't think there would be any advantage to doing that. What are you trying to accomplish?

The only time I've seen two antennas connected to one scanner is when they're using two yagi antennas to increase signal levels from two different directions, often 180 degrees apart from each other. Or when you are using one antenna for 850MHz band and another antenna for something like VHF/UHF, 150MHz & 450MHZ. I had done something similar to an 800MHz trunked system and VHF/UHF aircraft, and using a diplexer to couple the two antennas to one coax.
 

Saint

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
4,492
Location
Fort Erie Ontario Canada
I don't think there would be any advantage to doing that. What are you trying to accomplish?

The only time I've seen two antennas connected to one scanner is when they're using two yagi antennas to increase signal levels from two different directions, often 180 degrees apart from each other. Or when you are using one antenna for 850MHz band and another antenna for something like VHF/UHF, 150MHz & 450MHZ. I had done something similar to an 800MHz trunked system and VHF/UHF aircraft, and using a diplexer to couple the two antennas to one coax.
Just wondering if I would get better reception on weak signals.
Steve
 

Hit_Factor

Member
Joined
Mar 6, 2010
Messages
2,435
Location
Saint Joseph, MI
I have two Discone antenna's, could I get better reception if I used a good splitter and ran both Discones at the same time if the were around 10 feet apart.
Steve

You could try it for the cost of a splitter. It won't cause damage.

Antennas might be out of phase, creating a condition similar to simulcast distortion.

For specific weak siganls I might use a preamp, maybe a rotating yagi.
 

Saint

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
4,492
Location
Fort Erie Ontario Canada
You could try it for the cost of a splitter. It won't cause damage.

Antennas might be out of phase, creating a condition similar to simulcast distortion.

For specific weak siganls I might use a preamp, maybe a rotating yagi.
Ok thanks for the information take care
Steve
 

wtp

Member
Joined
Apr 3, 2008
Messages
5,914
Location
Port Charlotte FL
for reception only , there are no rules, you can try anything, wire, paper clip, wet noodle.
just to see if it helps or hurts in your particular situation.
 

Saint

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
4,492
Location
Fort Erie Ontario Canada
for reception only , there are no rules, you can try anything, wire, paper clip, wet noodle.
just to see if it helps or hurts in your particular situation.
Yes I'm thinking about getting a splitter and trying it, just like an antenna it might work for me with my setup and my area of scanning.
Steve
 

wtp

Member
Joined
Apr 3, 2008
Messages
5,914
Location
Port Charlotte FL
i had to do the same thing to get over the air TV ch. 11 when they went digital.
two TV antennas pointed is the direction of the tower and a TV/cable splitter used in reverse.
2 antennas into the TV way. and if a car came down the road the station went out. better than a doorbell.
 

mmckenna

I ♥ Ø
Joined
Jul 27, 2005
Messages
23,617
Location
Hiding in a coffee shop.
i had to do the same thing to get over the air TV ch. 11 when they went digital.
two TV antennas pointed is the direction of the tower and a TV/cable splitter used in reverse.
2 antennas into the TV way. and if a car came down the road the station went out. better than a doorbell.

Difference is the TV antennas have gain. The discone antennas don't.
Then you add a splitter that will have additional losses.

Like other said, give it a try, but don't expect a miracle.
 
  • Like
Reactions: wtp

Saint

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
4,492
Location
Fort Erie Ontario Canada
i had to do the same thing to get over the air TV ch. 11 when they went digital.
two TV antennas pointed is the direction of the tower and a TV/cable splitter used in reverse.
2 antennas into the TV way. and if a car came down the road the station went out. better than a doorbell.
There you go, it does not hurt trying something if it wont work OK but if it does work.... happy days.
Steve
 

ko6jw_2

Member
Premium Subscriber
Joined
May 18, 2008
Messages
1,448
Location
Santa Ynez, CA
You need to take into account the insertion loss of a splitter/combiner. I have a very high quality (up to 900MHz) one with an insertion loss of 3.5 DB. Then there is the loss from the impedance mismatch since the splitter is probably 75 Ohms and the antennas are 50 Ohms. Finally these are unity gain antennas so adding unity to unity is still unity. Much better to try to increase the height of the antenna and use the lowest loss coax you can afford.
 

Saint

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
4,492
Location
Fort Erie Ontario Canada
You need to take into account the insertion loss of a splitter/combiner. I have a very high quality (up to 900MHz) one with an insertion loss of 3.5 DB. Then there is the loss from the impedance mismatch since the splitter is probably 75 Ohms and the antennas are 50 Ohms. Finally these are unity gain antennas so adding unity to unity is still unity. Much better to try to increase the height of the antenna and use the lowest loss coax you can afford.
OK thanks for this information, I am thinking on changing the coax to a better product. I have rg58 now
Steve
 

iMONITOR

Silent Key
Premium Subscriber
Joined
Sep 20, 2006
Messages
11,156
Location
S.E. Michigan
I have two Discone antenna's, could I get better reception if I used a good splitter and ran both Discones at the same time if the were around 10 feet apart.
Steve

You still haven't told us what band (frequencies) you're monitoring.
 

ko6jw_2

Member
Premium Subscriber
Joined
May 18, 2008
Messages
1,448
Location
Santa Ynez, CA
OK thanks for this information, I am thinking on changing the coax to a better product. I have rg58 now
Steve
Definitely get rid of the RG58. Suggest LMR400 or equivalent. Only use 58 in short mobile installations or for short patch cords.
 

Saint

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
4,492
Location
Fort Erie Ontario Canada
Sorry Right across the bands, 108 to 174 MHz and 400 to 1300 MHz, I pick up a lot of frequencies in my area in Canada And United States from my apartment. I thought maybe RG-8 coax might be the way to go for upgrading my coax, only need a 50' foot run from scanner to discone antenna.
Steve
 

dlwtrunked

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
2,109
I have two Discone antenna's, could I get better reception if I used a good splitter and ran both Discones at the same time if the were around 10 feet apart.
Steve

Unless you place one directly above another, you are just as likely to get worse reception as better reception. In any case, the improvement is marginal--a few dB. I once had a commercially made discone of that sort (may still have it somewhere in my shed).
 

Saint

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
4,492
Location
Fort Erie Ontario Canada
Unless you place one directly above another, you are just as likely to get worse reception as better reception. In any case, the improvement is marginal--a few dB. I once had a commercially made discone of that sort (may still have it somewhere in my shed).
I might get better results upgrading my coax cable.
Steve
 

iMONITOR

Silent Key
Premium Subscriber
Joined
Sep 20, 2006
Messages
11,156
Location
S.E. Michigan
Sorry Right across the bands, 108 to 174 MHz and 400 to 1300 MHz, I pick up a lot of frequencies in my area in Canada And United States from my apartment. I thought maybe RG-8 coax might be the way to go for upgrading my coax, only need a 50' foot run from scanner to discone antenna.
Steve

Stick with the discone if your required bandwidth is that wide. Realistically there is no one antenna or even two together that will perform well over that range. What are you monitoring above 800-900 MHz? RG-8 will not perform well, there's too much loss at those frequencies.
 
Status
Not open for further replies.
Top