Air band directional gain base antenna

[n1chu]

I’m looking for a Air Band (118-136 MHz) yagi directional with gain to use at my house. I’m on the fringe of the airport’s tower, only reviving the tower when my squelch is approaching open. And of course, the scanner will open up on a frequency that has a higher noise floor and stay locked on it. So a directional gain antenna would help.

Any suggestions?

Thanks

 

[eorange]

No yagi suggestions, but, I was in the same kind of situation as you but a little worse. I wasn't able to receive Cleveland tower under any circumstance.

I built a dipole cut for 128 MHz, using copper pipe as the elements and PVC pipe to form the T. I am now able to pick up Cleveland tower and ATIS, but it's not a strong signal by any means. A beam would do better, but it was an interesting experiment.

 

[737mech]

Look at these styles

Look around for a log periodic like this DPD Productions - Base & Mobile Antennas for Radio Scanners: VHF, UHF, NOAA, Low-Band, 700 MHz, Police, Fire, Public Safety if you need directional, DPD no longer selling these but the Omni X model is also a great airband antenna. One question first have you tried an inline fm trap? First try that and see if Airband gets better on the scanner. Here's an example https://www.amazon.com/Broadcast-FM-Block-Filter-88/dp/B01LE9LRPM

 

[popnokick]

It would help to know what antenna you're using now that is not hearing the tower very well. The DPD Omni-X is a good airband antenna... as would be almost anything you could put on the roof, outdoors, up high. But have you considered that a directional antenna is going to limit your range for hearing aircraft that are not in the direction of where the antenna is pointed? If all you care about is the tower and maybe ground ops at the airport.... and not ARTCC, Approach, Departure, or inflight comms at greater ranges... then maybe a directional antenna will be fine for you. But I'm betting you don't want to give up the range on all those other interesting things to hear.

 

[trp2525]

I’m looking for a Air Band (118-136 MHz) yagi directional with gain to use at my house...

Antenna Products offers 2 VHF broadband yagi antennas that cover 118-136 MHz (spec sheet attached):

Model YG50 with 6 dBi gain and "N" female connector termination: VHF Broadband Yagi Antenna 118-136 MHz 6 dBi | Antenna Products Corporation

Model YG118 with 10 dBi gain and "N" female connector termination: NSN 5985-01-050-7520 VHF Broadband Yagi Antenna

 

[nycrich]

Best bet is to buy a Create Log Periodic 105-1300 Mhz. DX Zone sells them for $299. Heavy duty, can withstand high wind conditions and compared to other high gain antennas affordable. After +30 yrs of scanning and buying numerous antennas, this antenna has the highest gain , minimum 12 dbi. It is directional so you might need a rotor.

 

[Ubbe]

The Creative LP antenna has nowhere near a 12dBi gain. It has about 3 elements that resonate to one frequency that corresponds to max 6dB gain. The YG50 antenna has one reflector, two active elements and three directors, which should have considerable more gain than the LP antenna in the airband.

If you need to have gain in the whole range of 105-1300MHz then you can get the LP antenna, but why waste range and size to frequenceis above 800MHz and in the FM broadcast band.

If you are up to build your own antenna you can get a $30 LP antenna for television reception and use the many LP antenna calculators online and drill new holes in the boom of that antenna and move the elements to form a 118-137MHz LP antenna.

Look for this kind of antenna and either buy new aluminum pins that are longer or just add to the existing ones with screw terminals or hose clamps or similar.
https://www.ebay.com/itm/HDTV-TV-ou...Grade-10dBi-VHF-UHF-Log-Periodic/361707193412
https://www.changpuak.ch/electronics/lpda.php

/Ubbe

 

[prcguy]

I agree, comparing the Create to a couple of known military LP antennas of similar size, the gain is more in the 4 to 5dBd range.

For a number of years I had a Yagi similar to the YG118, the TACO Y102B-130V with 11.2dBi gain across 118 to 137MHz. It was up at the same height as a Kreco Discone and I had the opportunity to do range tests with an aircraft on multiple occasions, plus some random comparisons on receive with local towers. Compared to the Discone, this Yagi will bring weak crackling signals on the ground up to good readable levels.

However on ground to air tests in the only direction we could test, the aircraft faded out at the exact same point at 200mi out and the aircraft was usually around 35k ft altitude. Signal level on the Discone was slightly noisy just before the aircraft disappeared and on the Yagi it went from great signal to gone like you turned off a switch. Turns out there is a 7,000ft + mountain range 60mi away from me in the same direction and we think that is the reason for the abrupt signal loss. This probably doesn't matter to the OP but I always thought it was interesting.

Since these high gain broad band Yagis for the VHF air band are expensive and scarce its much easier to raise your existing antenna, which will improve reception of distant airports.

The Creative LP antenna has nowhere near a 12dBi gain. It has about 3 elements that resonate to one frequency that corresponds to max 6dB gain. The YG50 antenna has one reflector, two active elements and three directors, which should have considerable more gain than the LP antenna in the airband.

If you need to have gain in the whole range of 105-1300MHz then you can get the LP antenna, but why waste range and size to frequenceis above 800MHz and in the FM broadcast band.

If you are up to build your own antenna you can get a $30 LP antenna for television reception and use the many LP antenna calculators online and drill new holes in the boom of that antenna and move the elements to form a 118-137MHz LP antenna.

Look for this kind of antenna and either buy new aluminum pins that are longer or just add to the existing ones with screw terminals or hose clamps or similar.
https://www.ebay.com/itm/HDTV-TV-ou...Grade-10dBi-VHF-UHF-Log-Periodic/361707193412
https://www.changpuak.ch/electronics/lpda.php

/Ubbe

 

[nanZor]

I would try prcguy's suggestion of getting the antenna higher first.

However, if you are just needing to break the squelch, and still desire a wide beamwidth, then consider a "2 element" yagi for this situation.

I don't know of anyone who makes a commercial 2 element yagi, but here's a quick lowdown on amateur versions which one can get the idea and scale for airband:

A 2 Element Direct Feed Yagi for Multiple bands by WB2VUO

This probably should go into the build-your-own-antenna subforum, but thought I'd throw this out.

Direct feed, spacing not too critical, especially for scanner rx-only, and a fat cardiod pattern.

I've used them successfully to get beyond the "break the squelch" stage on certain systems, and also to put interference in a null just enough for the receiver to not desense on it. Easy to build, easy to point via the strong-arm method and so forth.

I've even "planted" a reflector behind existing fixed antenna setups when necessary to do this.

Not many people consider the 2-element yagi, because it doesn't have a LOT of gain, but in some circumstances, perhaps yours, it might be perfect.

 

[Ubbe]

One problem when building antennas from scratch are that it takes a lot of time. You have to find material for the elements, the boom and some sort of way to clamp it to a mast pole. It's much easier getting a cheap tv antenna that comes with all things you need like antenna connector and clamps at the same cost, or less, if you where to buy everything seperatly yourself. It's usually easy to alter the positions and lenghts of the elements to handle the frequency you want.

For a 2-3 element yagi you could get a FM broadcast antenna or TV antenna for the VHF band and modify it. They usually have more elements than needed that you can remove and use to lengthen the remaining, if the antenna where made for a higher frequency. You then also get the balun to connect the unbalanced coax to the balanced antenna.

/Ubbe

 

[byndhlptom]

Air band yagi

You can get some gain by just side mounting an Omni antenna, spacing it 1/4 wavelength (at preferred frequency) from tower/pole, turning it into a reflector at a specific frequency. This should give you a broad cardioid pattern with some gain

$.02

 

[nanZor]

That's worth investigating. No reflector tuning. If your mount is a backyard PVC pole, you could clamp or attach a reflector sized wire element to it, which by being tuned might work even better.....

Hence the "plant" I used before. PVC pipe mast with nothing but a reflector sized wire at the top, spaced a bit away from an existing hard-mounted antenna....

 

[Ubbe]

You can look at page B7 in this informative document from the antenna manufacturer Kathrein.
http://www.kathrein.fr/media/basicantenna.pdf
If you use a metal sheet reflector, or fine masked metal net, you move all the directivity from the back to the front and gain up to 3dB.

/Ubbe

 

[nanZor]

Or how about a 2 element vertical Moxon using MoxGen software? AC6LA has a quick description of how to go about it. For our use, just rotate it vertically.

https://ac6la.com/moxgen1.html

I've even seen variations using plastic coat-hangers indoors.