Dual Band VHF/UHF Amateur Base Antenna for Scanner Use

wmoreland

Member
Premium Subscriber
Joined
Dec 17, 2008
Messages
11
I recently purchased an Ed Fong DBJ-1 dual band VHF/UHF antenna with the intention to use it as a scanner base antenna. It will be mounted on the roof of the house with approximately 30-50 feet of RG8U coax (that I had already) routed through the attic and down into the house. The antenna end will have an N connector and the scanner end a BNC. I am located in a very rural mountainous area where I will be only monitoring 150-160 MHz and 450-460 MHz decoding P25. I am close enough to the two main sites I want to monitor to sporadically receive inside the house with a rubber duck antenna. Does anyone foresee any problems using this antenna for a scanner. Thanks in advance.
 

danesgs

Member
Premium Subscriber
Joined
May 21, 2008
Messages
175
Ed makes a version of that antenna specifically for 150/450. he will cut to the frequencies you want to monitor. Not sure how much of a loss there would be by using his HAM version. All of his antennas are superb. Been using the dual band 144/440 Ham version now at 25 feet and make it well into all the repeaters in the area.
 

prcguy

Member
Joined
Jun 30, 2006
Messages
8,225
Location
So Cal - Richardson, TX - Tewksbury, MA
I've measured J-poles and other amateur band antennas used out of band and there can be considerable degradation on receive. A simple 5/8 wave Larsen mobile antenna tuned for 146Mhz is about 20dB down at 162MHz weather channels compared to the same antenna tuned for 162MHz. That's from a real measurement and that is a huge hit in signal level.

I would recommend using an antenna designed for the frequency range you need, otherwise just be resigned to the fact your reception will be degraded.
 

vagrant

ker-muhj-uhn
Premium Subscriber
Joined
Nov 19, 2005
Messages
969
Location
California
I am close enough to the two main sites I want to monitor to sporadically receive inside the house with a rubber duck antenna.
If you are able to use that rubber duck antenna with your scanner outdoors and constantly receive the two main sites you want, I would say that Ed Fong wire and plastic antenna should work. As prcguy noted, if the antenna is not tuned for the frequencies you wish to monitor, it can reduce your ability to receive quite a bit. You are also introducing coaxial line to your system. This will also add signal loss.

The other side of the coin is you will be introducing an antenna that will probably receive "other signals" much better and potentially cause interference with signals you want to receive. This means that a nearby FM radio station with lots of RF power may cause interference, as well as a 152 MHz paging system, or a NOAA weather broadcast around 162 MHz.

From your post you appear to have the gear necessary to implement the new antenna and coax to your system, so try it and let us know how it worked out for you. ( As everyone's geographical location is different, including the potential for interference, one must experiment. )
 

wmoreland

Member
Premium Subscriber
Joined
Dec 17, 2008
Messages
11
If you are able to use that rubber duck antenna with your scanner outdoors and constantly receive the two main sites you want, I would say that Ed Fong wire and plastic antenna should work. As prcguy noted, if the antenna is not tuned for the frequencies you wish to monitor, it can reduce your ability to receive quite a bit. You are also introducing coaxial line to your system. This will also add signal loss.

The other side of the coin is you will be introducing an antenna that will probably receive "other signals" much better and potentially cause interference with signals you want to receive. This means that a nearby FM radio station with lots of RF power may cause interference, as well as a 152 MHz paging system, or a NOAA weather broadcast around 162 MHz.

From your post you appear to have the gear necessary to implement the new antenna and coax to your system, so try it and let us know how it worked out for you. ( As everyone's geographical location is different, including the potential for interference, one must experiment. )
Once I get it hooked up I'll post how it works out. Thanks for all the input.
 
Top