My first home brewed antenna

[kicktd]

For those not interested in monitoring aircraft/ATC/ACARS see the bottom of this post.

I am new to making antennas and antenna termonology so just bear with me here :lol:

Well I wanted some better performance for the Civilian Air Band mainly for Louis Armstrong Intl. Airport (New Orleans) and for ACARS. So I found the plans for an ACARS antenna that covered the band I wanted (approx. 108-174) and went to make my own design based on the length of the antenna. Now I know I'll probably get nit picked about it but hey, it works great.

Total cost: $0. I used what I had around the house, 2 old aluminium lamp poles (1/2" in diameter) which surprisingly were the lengths I needed and provided an extra element (slightly smaller than the 1/2" main pole) which made a difference and helped pull in those weaker signals.

Here is a PDF with the design and measurements Here. The red lines feeding into the PVC T are the connectors for the 300 to 75 Ohm Balun I used. I used screws that came on the lamp poles to hold the ends in place and using needle nose pliers to close the fork around the screw for extra hold and contact support, making sure to seal them with some weather proof sealent.. The main "pole" faces up and down just like in the PDF. I Held the antenna while rotating it slowly to see which direction would work best and this position gave the best results.

I will post a picture of what it looks like on my antenna pole. So far at around 15, 20ft tops I am getting ACARS transmissions as far away as 340+ Miles as the crow flies. I am picking up planes locally (around 60 miles to KMSY) all the way down and with tower clear as a bell. Ground frequencies are there but can't make anything out and I plan on raising the antenna up higher today to see if it gets better reception. Also I can faintly sometimes make out the actual ATC transmissions from 60+ miles from the tower and hoping that improves also with raising the antenna.

Over all for a "free" antenna it sure is kicking the butt of my $25 RS 20-176 (same height etc.). I would be lucky to hear New Orleans APP/DEP Aircraft from where I am at with the 20-176, and it would be mixed with lots of static, never could hear aircraft on the tower frequency either.

Also for those not interested in aircraft/ATC/ACARS this antenna does an OUTSTANDING job for the conventional public safety band. Picking up stuff that use to come in with static with the 20-176 CLEAR now with my home brew antenna.

Edit: Here is a picture of how it looks. It's the Antenna on the left. It's gray and rainy here so it makes the image look awkward and like it's not level. Also makes it look like the 20-176 elements are close to my home brew but they aren't.

 

[nighthawks]

Coax

Hey, all sounds good on what you've done.

When your done tinkering, you should wire tie your coax up to the mast so it not blowing around on windy days, to much weight pulling down on the antenna(s)connections.

 

[Skypilot007]

Nice! Very simple but effective. I like it.

 

[kicktd]

When your done tinkering, you should wire tie your coax up to the mast so it not blowing around on windy days, to much weight pulling down on the antenna(s)connections.

Yeah I didn't want to do anything too permanent until I knew it was working as it should. Now that I know it's working I'm Gonna be tieing them up today.

Nice! Very simple but effective. I like it.

Thanks! I was aiming for something simple that anyone could do (me included :lol

 

[Don_Burke]

That looks great. You might want to try it without the balun.

 

[kicktd]

That looks great. You might want to try it without the balun.

I would, but I just don't know how to yet. How would I go about making it where I wouldn't need the balun? Yes still new to this :lol:

Today while scanning my banks (a lot of stuff is still conventional around here) I heard something come up over 155.235 PL 179.9 clear as a bell. Had it tagged as Mandeville EMS (No PL) but didn't sound anything like them as far as locations given (I've never gotten a hit on this freq, even on the sputnik) so I went looking around in the RR database for a matching PL tone and freq and it ends up it belongs to AMR Ambulance out of Adams County, MS which is a good 80-90 "air" miles from me! My home brew keeps on amazing me

Now I just need that premium membership to keep looking up all these frequencies :lol:

 

[Don_Burke]

How would I go about making it where I wouldn't need the balun?

You can strip the end of the coaxial cable and connect the center conductor to the top element and the shield to the bottom element.

Another possibility is to use a chassis mount F connector on your antenna.


That balun you are using is actually two items in one, a balanced to unbalanced matching unit (that is where "balun" comes from), and a 4:1 matching transformer for matching something with a 300 ohm impedance to something with a 75 ohm impedance. You do not need the matching transformer and I suspect the balun function is very little help in this application.

 

[chadbyoung]

Cool Antenna

Could you post some up close pictures of the antenna and how you connected it to the cable? What cable type did you use? Do you have an amplifier attached?

Thanks
Chad

 

[kicktd]

You can strip the end of the coaxial cable and connect the center conductor to the top element and the shield to the bottom element.

Another possibility is to use a chassis mount F connector on your antenna.

Thanks for the info, It'll help me out a lot . I basically just used what I had on hand to see if it would even work :lol:

Could you post some up close pictures of the antenna and how you connected it to the cable? What cable type did you use? Do you have an amplifier attached?

Thanks
Chad

I'll try to get some close ups. Basically all I have is each end of the balun is connected to the top or bottom element held in place with a screw on the bottom side of each pole which was already was part of the poles I used, so I made use of it. No amplifier and cable type is RG-59U with type F connectors. yes I know, not the best but like I've said I used what I had on hand.

To be honest I didn't think I would be seeing the results I am getting. I thought I would only get a slight range increase but not as big as I am getting! I am actually having to use the CT option of my Pro-97 to sort out who I'm hearing and where.