155 MHZ base - best yagi for long distance rural

I need to pickup stations in the 155MHZ range from a tower about 60 miles away.

I'd like to buy something off the shelf for about $100 and have it work great.

My research seems to indicate I should get a yagi.

Which of these two antenna's would be best for me? Or is there something better? What chance do I have of picking up from 60 miles away? The land is flat, no mountains.

HBU55 - high vhf TV antenna
AntennaCraft UHF/High-Band VHF Outdoor HDTV Antenna (HBU55) from Solid Signal

or

Aston 155
http://www.theantennafarm.com/catalog/astron-155-4-4390.html

Thanks!

Are you going to be transmitting ? If yes I would go with the antenna from The Antenna Farm

pdrayton said:

I need to pickup stations in the 155MHZ range from a tower about 60 miles away.

I'd like to buy something off the shelf for about $100 and have it work great.

My research seems to indicate I should get a yagi.

Click to expand...

Correct, a Yagi would be a good choice. Help us out a little bit though, letting us know where you are and who you are trying to listen to can help a whole lot. While terrain between you and the transmitter is an important factor, knowing what sort of transmit power they are using, how high their antenna is, etc. can all really help us guide you in the right direction.

If the transmitter is down low to the ground and running low power, you will likely have issues. If they are high on a mountain or a tower and running high power, you may not need much at all.

Also, the antenna is only part of what you need to consider. The height of your antenna is very important, and the type and length of coaxial cable is very important. Use a long length of cheap coaxial cable, and the losses in that cable will negate the benefits of the higher gain antenna.

pdrayton said:

Which of these two antenna's would be best for me? Or is there something better? What chance do I have of picking up from 60 miles away? The land is flat, no mountains.

HBU55 - high vhf TV antenna
AntennaCraft UHF/High-Band VHF Outdoor HDTV Antenna (HBU55) from Solid Signal

Click to expand...

This one is a TV antenna, and while it -might- work, it is not necessarily tuned for the right frequencies. Also, TV antennas are usually mounted with horizontal polarization, and most land mobile radio systems use vertical polarization. You'd need to modify the mount, and even then, it may not be your best choice. Others have used TV antennas with good results, but you can do better.

pdrayton said:

Aston 155
http://www.theantennafarm.com/catalog/astron-155-4-4390.html

Thanks!

Click to expand...

Of the two, this is your better choice. That's kind of a low grade antenna. It'll work fine, but it may not last long.

You really need to consider good coaxial cable. Make sure you figure that into your system.

Thanks for the replies!

Here's more on my situation.

I am receiving only.

I am in St Marys, 60 miles east of Waycross georgia, trying to capture the Fire dispatch channels from Waycross/Ware 154.100 (see link below for details)

Ware County, Georgia (GA) Scanner Frequencies and Radio Frequency Reference

I have a basic analog non-trunking scanner which works fine for Camden county Fire/EMS 155.880
Camden County, Georgia (GA) Scanner Frequencies and Radio Frequency Reference

Forgot to ask...

How do I know if I have 'good' coax cable? I have a 50 ft BNC 75ohm (i think) coax from radioshack. Rcommendations?

At present I have an ST2 (basic disc cone) about 12 ft high in a ware house roof space. It picks up my county and the next county over (charlton) pretty well. I can mount the new antenna higher on a pole if needed.

"Radio Shack" and "Good Coax" usually are mutually exclusive. Radio Shack doesn't sell good stuff, but "good" is relative.

If it's 75 ohm cable, it's likely either RG-59 or RG-6, depending on when you purchased it. It'll say on the cable jacket. Knowing what it is will help….

Beware of people trying to tell you that 75 ohm coaxial cable will not work with a scanner or scanner antenna due to the radios/antennas having inputs designed for 50 ohms. It really doesn't make a noticeable difference.

So, your cable/antenna:
1. How much cable do you --actually-- need? Using just the amount you need will help reduce cable induced signal losses.
2. Is your antenna mounted above the roofline, or is it located inside a building? If it's inside, what is the roof made out of?
3. How high can you -safely- get your antenna? Higher is better when trying to improve coverage. The higher it is, the farther away the horizon is.

Good coax:
Depends on the length you need. If it's a short run, less expensive cable will work just fine. If it's a longer run, you will need a higher grade coax.
Radio Shack RG-8 is about as good as you'll find in their stores. It's not great stuff, but if it's all you can get, it's all you can get.
A better choice would be to purchase Times Microwave LMR-400 cut to length and professionally terminated. There area number of sellers on the internet that will do this for you. Make sure you are getting -real- Times Microwave brand cable, or one of the bigger name brands. There are a lot of dealers using cheap Chinese knockoffs that do not perform as well.

Important:
LMR-400 and similar cables are stiff. Do not attempt to connect them directly to your scanner if at all possible. It will put a lot of stress on the connector on the radio, and will risk breaking it. Standard procedure is to use a short length of smaller, more flexible coaxial cable to make the transition to your radio.


So, recap:
Good Yagi antenna up as high as you safely can, out in the clear.
Good coax, as short as possible (no extras rolled up somewhere wasting signal).
Properly installed connectors to match the antenna.
Flexible jumper at the radio end.

st2

pdrayton said:

Forgot to ask...

How do I know if I have 'good' coax cable? I have a 50 ft BNC 75ohm (i think) coax from radioshack. Rcommendations?

At present I have an ST2 (basic disc cone) about 12 ft high in a ware house roof space. It picks up my county and the next county over (charlton) pretty well. I can mount the new antenna higher on a pole if needed.

Click to expand...

P: For what its worth, I've run my ST2 antenna on up to 100' of RG6 cable without a preamp, and it's only about 25' off the ground on a tower. It blasts on VHF-Hi band signals. if you're using your antenna inside a metal warehouse building it would probably work much better if you take it above that roof, or use a pole/tower. Good luck, and watch the power lines!

I have 50 ft of radioshack rg-58/U cable between my ST2 and the scanner.

The ST2 antenna is in the roof space, 10 ft high. I only need as much cable as the height of the antenna.
the roof is made of wood and shingles.

Are you saying I might be able to get the 60 mile away high vhf towers with this antenna higher up?

I saw the channel tower details here
WXT503 (WARE, COUNTY OF) FCC Callsign Details

The antenna tower is 127ft high, elevation 42. I'm at sea level, so it is about 160ft high with no mountains between me. Just trees around my office that the signal would have to go through.

"Depends"….

Moving the antenna up higher will give you a farther "radio horizon". Since a lot of VHF/UHF frequencies work more line of site, getting your antenna up higher will allow you to hear more.

Before purchasing a different antenna, try raising yours.

Also, RG-58 is pretty low grade cable. While it will work, you can improve performance by installing better cable.
At 155MHz using 50 feet for RG-58, you are losing 2.6dB of your received signal just in feed line losses. That's almost half your signal.
Stepping up to RG-6 will lose about 1.75dB, or about a 1/3rd of your signal.
Using RG-8 would lose about 0.8db, or about 20% of your signal.
Using LMR-400 would lose about .75db of your signal.

st2

I'm with mckenna...go for height if you can do it. Most of the posts I've seen here and in other forums always recommend placing your antenna as high as practical, getting over the trees and any other obstructions may do more for you than any other single change to your equipment. I have a homemade ground plan, cut for 155mhz, just copper wire and pvc pipe parts, and it rivals my ST2 antenna, and it's only about 10' higher than my ST2 ! I believe it is because the ground plane is able to "see" over more of my trees.

OK, great advice.

So I'll get some RG-8 from Radioshack, since they are the only local store for me. They only have rg-8/X but from the reviews and specs it seems much better than my rg-58.

RadioShack 100-Ft. RG8U Coaxial Cable w/ Pull Box : Coaxial Cables | RadioShack.com

My antenna has a so-239 and I have a converter from So-239 to BNC at the scanner.

I'll put the ST2 up higher and see what happens. If that doesn't work, maybe doublescan, could you point out where I could get the design for the antenna you made for 155MHZ? Or I'll buy that aston 155MHZ.

Wait!!!!!

RG-8 and RG-8X are different cables. RG-8x is slightly better than RG-58, but not by much. The effort you'll go through to replace the cable will not improve things much. Radio Shack used to sell RG-8 in 50 foot lengths, terminated with the UHF connectors to match your antenna.

You'd have better luck ordering the LMR-400 online. It'd make the labor of installing new cable worth it.

Try using the calculator at the URL below:

VHF/UHF Line of Sight Calculator

The results from this calculator demonstrate the importance of antenna height. I used 160 feet and 30 feet for the antenna heights which resulted in a line of site distance of 26 miles. This result does not mean you can not receive signals from a transmitter further away, it just tells you the maximum distance for mostly reliable communications.

There are many factors involved in signal propagation and reception that are specific to the transmitting site and the site where the receiver is located.

The URL below is fun to play with and demonstrates the effects of terrain and distance on terrestrial TV signals.

TV Fool

I have not found a site that allows one to enter the coordinates of two stations and perform the same calculations as the TV fool site noted above. A site like that would tell you exactly what you would need to receive your distant station.

Thanks guys. 36 miles doesn't sound promising...

McKenna, regarding cable, is this a good option. It is the times cable from what looks like a professional supplier -

Times Microwave® 10 50 ft LMR400 Antenna Jumper Coax Cable SMA M F RF Connector | eBay

I'll have to check what connectors my scanner and antenna have, but if they are different to what comes on the cable, is using an adaptor a bad idea?

Yeah, but those connectors are not going to do you any favors. Best to get the right one to match the antenna.

---use a short flexible jumper to transition from the LMR400 to your radio. Trying to connect this cable directly to the radio will put a lot of stress on the connector, and risk damaging it.

ground plane antenna

BUILD A GROUND PLANE ANTENNA FOR 2 METERS AND MORE - SIMPLE AND EASY!

That's just one of many on the web. I think that one is strictly for one band, which was all I was worried about anyway. You just cut the vertical element for the freq you want, for 155 I believe its about 18 inches, but there are plenty of calculators to show you exact dimensions. A simple ground plane like that is somewhat broad-banded. I cut mine for the aircraft band, and they pick up the VHF-Hi excellently, even up to the weather radio frequencies.
Google 'ground plane antenna plans' and you'll find lots of them, some even have the secondary elements added for UHF frequencies.

Thanks, I saw that ground plane antenna plan a while ago. I thought a yagi was better for long distance, directional signal pickup. And my existing ST2 is a ground plane, right?

pdrayton said:

And my existing ST2 is a ground plane, right?

Click to expand...

No, it's a compound dipole with elements of various lengths intended to resonate at a variety of frequencies.