Which would you think would be my best bet. It seems like the discone I have on the roof can't reach out enough and just wondered if my old Diamond X510HDM would be a better bet if I install it. At present I'm trying to reach out to some digital signals that just don't want to make it. Is there a way to boost an antenna without costing a lot and will it really help? Maybe there is a super antenna I should be thinking about. Thanks Ron
Ron, it depends on how far you are trying to hear, and if it's 800 mhz trunked signals, then you are going to need a
good antenna. If you know the direction of the signals, you could purchase, or build a beam antenna (check E-bay)
and mount that outside. Lots of times, ham antennas will work, but maybe a better solution would be to get a
new TV digital antenna beam, and use that. TV signals with the new digital signals are in the UHF or higher bands.
You can use TV grade 50 coax on scanners. I've used TV grade coax connectors, too. It works. Try experimenting.
I looked at the amateur radio antenna. It is a dual band 2 meter/70 cm antenna. If you are trying to listen to VHF/UHF on your scanner it should do pretty well. If you are trying to listen to other things, it might actually degrade performance. A discone is a great antenna for all around monitoring, but it offers no gain.
With regards to feedline, again it depends on what you are trying to use it for. I used 9913, but if I were trying to pull in UHF or 800 MHz, I might spring for LMR400. Feedline isn't cheap, but it will be worth it in the long run.
A discone is a broadband antenna designed to pull in may different frequency bands equally poorly (it's a unity gain antenna). What it lacks in gain it makes up in broadband coverage.
If you want more gain, you'll have to make a compromise in the bands you wish to receive. If, for example, you only want to hear 800 MHz systems, you'd get a dedicated 800 MHz antenna. It will work great on that one frequency range it's cut for but won't work well (or at all) on any other frequencies.
Another approach is the Scantenna which has several different receiving elements, each cut for a specific scanner frequency which you're probably interested in. It will have more gain than the discone but not a completely flat broadband reception from 30 to 1200 MHz like the discone.
For the ultimate in gain, you want a directional Yagi antenna for the desired frequency. There's a type of Yagi called a log-periodic which can pull in a fairly wide range of frequencies but it is also so directional that it must be pointed directly at the system you're trying to hear. A rotator may be necessary for a Yagi-type antenna.
Better coaxial cable is necessary as you go up in frequency or longer in cable length. RG-58 is OK to about 50 feet up to 150 MHz. Above that you'll want LMR-400 cable which is about $2.00/ft. I use RG6 quad-shield (75 Ohm) for my discone and it works great. Your mileage may vary.
Bob Peloquin - KB1VUA
RR db admin (Massachusetts), USA
Scanner/GPS/Ham Radio enthusiast