Request for Assistance Choosing or Building an Aircraft Antenna for Indoor Home Use

[joeschmuckatelli]

So I bought my father a Whistler scanner WS1095 and he really likes to listen to the Aircraft bands (brings him back to when he use to fly). I know the frequency range is 118 to 137MHz. The cheap telescoping antenna is of course crap.

The new antenna would need to be an indoor unit and it would be next to an exterior wall on the second floor of my house. In my current home I cannot mount an external antenna due to HOA restrictions but I know that would be ideal if I could mount it outside on the roof.

I'd like to either build or purchase an antenna. Building one is of course significantly cheaper and I looked into a J-Pole design using .5" copper tubing (pretty easy build) but I'm unsure if it would be good for the entire frequency range or what might be a better choice.

Additionally we are not close to the airports at all. I live in King George, Virginia and trying to get both DCA and RIC towers which are basically 50 miles away. Yea, I may be too far away but I'd like to hear some possible options. Dad is not a young man and I'd like to make him as happy as I can.

So my questions are:

Is a J-Pole antenna good? I'd build it for center channel of 124MHz since most of the key frequencies are in the lower section of the band (119.1 to 128.125 MHz).

Is there a better design antenna be it something I can build or purchase?

And if you think this is better asked in the Amateur antenna section, let me know and I'll post the question there.

P.S. I'll likely build the J-Pole antenna tomorrow since it's such an easy thing to do and shouldn't cost much at all, but I'd still like to hear opinions from the talented folks here.

Cheers!
-Joe

 

[toastycookies]

If you want to make your old man Happy you need to put that antenna on the roof.

If you are not up to the task his wife is and you should leave now.

 

[joeschmuckatelli]

If you want to make your old man Happy you need to put that antenna on the roof.

If you are not up to the task his wife is and you should leave now.

If only it were that simple.

 

[popnokick]

From King George it is very unlikely you'll hear DCA or RIC towers. They direct their RF energy skyward, and the ground coverage around the airport is usually 5-10 miles if you're lucky.
However, aircraft in flight can be heard for hundreds of miles, particularly when using enroute ARTCC, ARINC, and air-to-air frequencies. As a pilot, your father will know this.
The antenna from the RR Wiki (below) is going to work better than a J-pole for aircraft. It is extremely simple and inexpensive to put together.... scroll down to the wire version at the bottom of the page. If possible, hang it in a 2nd story or higher window or attic. Many users here on RR report good results with it on both the civilian and military air bands. You'll need an adapter from the 75 ohm coax F-connector to the WS-1095 -
Homebrewed Off-Center Fed Dipole - The RadioReference Wiki
If you'd rather purchase something than put together your own, $90 gets you this indoor antenna -
DPD Productions - Aviation Base & Mobile Antennas: Air Band, VHF, UHF, ADS-B, 1090 MHz, ATC, FBO Base, PCL, AWOS, ACARS
I'd recommend trying the Off-Center Dipole first.

 

[wyShack]

Put the antenna (I would recommend the OCFD or a home made 1/4 wave) up in the attic if you have a shingle roof and it will work fine. otherwise get it near a window so it can 'see' outside. Along with the towers, you and your Dad can listen to Air traffic control which will likely be as active. You can get frequency information from sites like AirNav or www.Skyvector.com - The Skyvector site is composed of enroute aviation maps or 'sectionals' that will bring back more memories as your dad used to be a pilot. either site will give you plenty on frequencies for your area. Air band is 'line of site' so you will hear the aircraft much further than the ground stations.

Have fun and enjoy the air band.

 

[joeschmuckatelli]

Thanks for the feedback.

We did build the J-Pole antenna and the antenna is near a window facing north so line of sight to the DCA Tower. But of course the DCA Tower intermittently comes in. I'm unable to place this in the attic space either due to it's height.

Next on the agenda is to build an OCFD antenna using the link popnokick provided. I'm about to order a handful of parts off the internet because I know we will be investing more time and money into this project. I'm certain we will be purchasing a magnetic mount antenna for his car and he wants to drive up closer to DCA to see if he can get all the stations we programmed into the scanner.

So as the crow fly's my house is about 45 miles from DCA. I have no idea if I can get a good signal from this distance but I'm going to continue to try. I can only get an antenna as high as about 20' above ground, or 190' above sea level. I was also looking at possibly building a high gain directional antenna which touts 9.5 dbi. The problem with this is the size, it's basically 4' x 4' (I'm generalizing it). I could put this in the attic space but it's not an easy thing to get to due to the way the attic is constructed. More attic investigation needs to happen before I consider building the large directional antenna, plus it will cost me about $50 in copper wire for the elements.

Again, I'm all ears and willing to learn and do some research. I can say this, there is so much information out there, it's a bit overwhelming at times. And I have questions that I would expect to have simple answers like how to join two or more antennas, for example I would want to join both a directional and omni-directional antenna together, and maybe a different frequency antenna as well. Every site I have visited always assumes that I'll be transmitting yet I'm only receiving. It's that gap there that is probably causing me the most grief. Eh, I'll get through it.

I appreciate the help everyone has given me.

 

[cmdrwill]

A simple groundplane antenna, I am sure someone can find/post the link for the one built on a SO239 coax connector.

 

[se]

Hi. I have a Watson micro or mini magnet mount antenna right on top of my BCD536hp and it works pretty good for me given my location, and maybe the Wellbrook brand might be an option for you.

Sheldon.

 

[popnokick]

But of course the DCA Tower intermittently comes in. ...
...I was also looking at possibly building a high gain directional antenna which touts 9.5 dbi. And I have questions that I would expect to have simple answers like how to join two or more antennas, for example I would want to join both a directional and omni-directional antenna together, and maybe a different frequency antenna as well.

Are you certain that what you are hearing intermittently is DCA tower? If you are on that freq you are more likely occasionally hearing aircraft working the DCA tower. 45 miles from a receiving antenna on the ground Is almost unheard of for control towers except under very unusual propagation... and that phenomena would not happen often if at all.
High gain directional antennas are very seldom used for reception of air comms. High gain directional antennas (e.g. Yagi) generally have very narrow beam width in both the horizontal and vertical direction. So if you do succeed in hearing the tower at any airport, you will immediately lose the reception of every aircraft that climbs to altitude away from the tower (and they tend to do that). Likewise, you are not likely to hear aircraft on approach to the tower.
Using multiple receive antennas sometimes works, but the effect can be very unpredictable without the right coupler / duplexer and tuning. Your best bet is to get the OCFD into the window... even better, the attic. If that shows promise, you may want to buy an omnidirectional gain antenna for the VHF aircraft band. Stick with the omni antennas... you'll hear LOTS more.
Also- Have you used the search function of the scanner? If not, try it. Get a pad and paper. Set the low end search freq to about 118 mHz, and the high freq to 137 mHz. Press Search (or whatever is needed to start the search on your scanner). Jot down every frequency that scanner stops on and you hear aircraft transmissions. Do this on and off for a few hours or days. Then start cross-referencing what you hear with the aircraft freq listings here on RR and elsewhere to determine what you're hearing... and from where (the listings will say).

 

[joeschmuckatelli]

Right now we believe we are hearing DCA Tower on 119.1MHz but it's very intermittent and it sounds like they are giving orders but it could be an airplane talking to the tower I guess. There are quite a few other frequencies four of them for approach East/West which come in very clear but me not being a pilot, it's all Greek to me.

Yes, the Yogi is what I was looking at but it would take me weeks to commit to building it if I had to go down that path. I will build the OCFD first and give that a shot. The idea of just joining a 4' and 18" wire to a 300 ohm TV antenna transformer blows my mind but I can do that, I just need to buy the transformer.

You mentioned an omnidirectional gain antenna, could you give me an example? I looked up a few things but maybe high gain means 2 dbi or greater? I was thinking high gain was 6 or more, I'm selfish.

The scanner is programmed with all the ARTCC frequencies for the Washington DC area (ZDC) so we do hear all those conversations as well.

I'll have to read up on how to set the scanner up to scan from 118 to 137 MHz, I'm sure it can do it. Also we can set the scanner up to record the transmissions, just not sure if I can do that with the searching like that but I know I can definitely set it up for defined frequencies.

 

[wyShack]

As we are dealing with aircraft, I would not recommend a 'gain' antenna. Gain antennas work by focusing on the horizon and you want to hear planes which are often above you. I like 1/4 wave antennas for aircraft listening as they hear 'up' as well as to the horizon. Aircraft overhead are obviously closer and therefore you can take the above with a bit of salt

 

[jim202]

You mentioned there was not enough height space in the attic. Just how high is the attic space in the center? Most homes in the north east have a high pitched roof where there is enough space to be able to stand up in the center of the roof space.

The next problem would be getting the coax from the attic antenna to the room where your looking to use the scanner. The age of the house comes into play here. If it is say in the order of about 10 to 15 years old, there are probably fire stops in the walls about mid way up. So getting a cable down to an outlet box height will involve trying to drill a hole in the horizontal 2x4 fire stops in the wall. An internal room wall is the best and the use of a really long drill. They make special drills for this purpose that have a hole drilled into the tip so you can attach a wire or strong string to it and pull it back up to the attic. This only works for single story homes. If you have a 2 story home, your SOL.

If you can use this method, let me know and I can provide more details.

 

[w8prr]

Aircraft antenna

Another way you might try is on your computer. The site LiveATC is great, I know it has KDCA and MANY others. There is no set fee, they do ask for a donation, but get very few. I'm sure your dad would love it.

 

[popnokick]

I will build the OCFD first and give that a shot. The idea of just joining a 4' and 18" wire to a 300 ohm TV antenna transformer blows my mind but I can do that,

You mentioned an omnidirectional gain antenna, could you give me an example? I looked up a few things but maybe high gain means 2 dbi or greater? I was thinking high gain was 6 or more, I'm selfish.

The OCFD is well-suited to VHF aircraft monitoring because it has very wide bandwidth in the VHF aircraft band. It also offers some gain over a quarter-wave or discone, and is omnidirectional... including upward to the sky. It's not going to get DCA tower directly, but offers very good aircraft performance for the time / money you put into it. Lots of reviews of this time-tested antenna are here on RR. Just use the Search function and OCFD or Off-Center Fed as your search key.

When I wrote "high gain" I meant vs. a quarter-wave or discone antenna... neither of which has any gain. Yagi antennas exhibit gain primarily in one direction. But contrary to popular belief, there are omnidirectional gain antennas that do not focus their pattern at the horizon. Here is one designed for receiving aircraft that offers 3db gain (VHF) and 4 db UHF (Milair) unlike the indoor antenna I linked in my first post. This can be installed if you have room in the attic / crawl space -
DPD Productions - Aviation Base & Mobile Antennas: Air Band, VHF, UHF, ADS-B, 1090 MHz, ATC, FBO Base, PCL, AWOS, ACARS
At 45 inches tall it is going to require more time to install (and money) than the OCFD. As before, there are many reviews of this antenna here on RR. Search is your friend.

 

[flythunderbird]

A simple groundplane antenna, I am sure someone can find/post the link for the one built on a SO239 coax connector.

In case the OP is interested ...

https://www.scribd.com/doc/845071/SCANNER-ANTENNA

OP, all you would have to do is cut the vertical element and the ground plane radials to the proper length. You can skip the 450 MHz and 800 MHz verticals.

 

[chief21]

another option... check out the VHF AirBlade Indoor antenna at DPD Productions:

DPD Productions - Aviation Base & Mobile Antennas: Air Band, VHF, UHF, ADS-B, 1090 MHz, ATC, FBO Base, PCL, AWOS, ACARS

John AC4JK

 

[joeschmuckatelli]

Thanks all for the advice. I'm waiting on a few 300 to 75 ohm balun transformers to arrive and then I'm going to try the OCFD antenna first.

As for the attic, it's all hunched over space and crawling through blown in insulation, HVAC duct work, and wooden frame work. Drilling through walls is not a problem (just takes planning and time), I wired my house for Cat 6 Ethernet so I'm very familiar with the fish tape and fire stops (no fun). The home is only 8 years of age.

@flythunderbird thanks for that link, I like that. I will need to look into the math here as I would expect the center rod to be a little longer for the 118MHz band. I would also add the additional smaller rods, it's just so easy. These are all nice little projects and eventually one of these will become my dad's favorites.

Thanks All !

Happy New Year

 

[fredva]

Joe, if your father is interested in military aviation, you might put in the NAS Pax River frequencies, if you don't have them already.

 

[joeschmuckatelli]

As an update:

We built the OCFD antenna and it works well on frequencies other than the aircraft band, the J-Pole we built actually works better for aircraft band but we still cannot pull in the DCA Tower frequency reliably. So this is the end of our antenna adventure for right now, well unless my dad wants to continue chasing the dream. Hopefully in about 6 months we will relocate to Jacksonville Florida area and be able to pull in the JAX airport but that is a long time from now.

I will have to check to see if we have the NAS Pax River frequencies programed, thanks for that info.