Do I Need a Discone Antenna?

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dickeydooo

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I'm pretty much a noob to scanners and frequencies and what not. I live 3.6miles due south of NASJRB Fort Worth. I am a total AvGeek so this locations grants me the ability to run outside like a little kid every time I hear a jet. To make it worse, I work from home. I'm pretty sure my neighbors think I am nuts. Last year I bought a BCD396XT and learned how to program it with all the NASJRB frequencies. I love it, picks up quite a bit but the clarity is hit or miss. Most of the time it is pretty crappy quality. I have been toying with the idea of putting up an antenna but not sure if I want to do one outside.

I am looking for some recommendation on whether I should just purchase the WAN-97A Active Nomad Base Antenna and hang it up around my window next to my desk. Then just plug my BCD396XT into or if I should look into putting a Discone Antenna above my garage in the attic then later on transition it to a pole on the roof.

I don't want to put up a pole quite yet because my wife would flip sh*t and we all know happy wife = Happy life.

Will putting up either a discone in the attic or the WAN-97A really provide me the clarity/upgrade that my little portable deserves? Which one would be best? Right now I have a Diamond SRH77CA on it and it has improved compared to the stock antenna. Again, indoors quality is not great.

Bonus question - Is the WSM-225 a good choice for my pickup?

Links:
WSM-225 Airband Magnetic Whip Mobile Antenna | Scanner Master
WAN-97A Active Nomad Base Antenna | Scanner Master
WBD-40 Discone Base Antenna | Scanner Master
D130NJ Diamond Super Discone Antenna | Scanner Master
 

br0adband

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If you're literally 3.6 miles from the airport that should be more than adequate range to pick up literally everything from the airbase itself, even ground traffic between aircraft and the tower, or ground crews as well. Having said that the obvious answer is YES a better antenna will improve things, sometimes rather dramatically, over any stock rubber ducky on any scanner ever made, that's just a simple fact that cannot even be debated. Where I'm located in Las Vegas I'm basically at a mid-point between Nellis AFB and McCarran International - Nellis is about 6 miles NE of me and McCarran is about 6 miles SE of me, and I can get quite a bit of stuff from both without a lot of issues and I'm using what's called an Off-Center Fed Dipole I learned about here at RR, you can find more info here:

http://wiki.radioreference.com/index.php/Homebrewed_Off-Center_Fed_Dipole

Which antenna should you/whoever get is where things get tricky. A discone is a primarily designed to be a wideband antenna overall and while there are some that are designed to specifically operate on the MilAir band (225 MHz to 380-400 MHz) most of the consumer available models do well in the CivAir band (118-136 MHz) as well and looking at the RR database entry for NASJRB it does have quite a bit of traffic in both bands.

I don't think in your situation that a discone will necessarily make a gigantic difference but it can, absolutely, and putting it in the attic could absolutely help things over what you've got right now if all you're using is the stock antenna on the BCD396XT. A telescopic whip would be better than the stock antenna as well but all this depends on your usage: is monitoring the airbase traffic the only thing you actually care about doing or do you actively monitor other bands, public service, Ham bands, commercial traffic (meaning local businesses, etc) which is a question that needs to be addressed.

Honestly, and I'm being completely serious here, I'd say build one yourself - make a 1/4 wave ground plane from coat hangers and an SO-239 chassis mount and be done with it. You'd be amazed at what's possible and considering the pricing on those antennas you linked to I think you'd be better off with something that doesn't cost anywhere near that much (hardly anything really, a couple of dollars at most) or the need to get it mounted someplace proper. Sure you could put one of them together and place it in your attic but again, that seems like a considerable expense for such antennas when something much simpler could do the task just as well if not better in most situations.

Here's the most simplistic set of plans for a 1/4 wave ground plane you're probably going to find:



For a 1/4 wave ground plane designed to handle the CivAir and MilAir bands you'd be looking at the main vertical element (A) being 22.1 inches (cut to 127 MHz which is the center of the CivAir band) and the 4 ground elements (B&C and D&E) being about 23-24 inches - it's usually a good idea to give the ground elements just a tad more length so about an inch or so can't hurt there but you can make them the exact same length if you wish, it's not going to ruin things to any measurable degrees. The mount is an SO-239 chassis mount like this, available for a few bucks from Fry's or maybe another electronics store near you or available on Amazon/eBay/etc:



You can attach the elements directly (assuming it's coat hangers but you can use anything that's similar like #12-14-16 gauge household electrical wiring, etc) by soldering them or using spade lugs with screws and nuts for the ground elements, soldering the main vertical element in place, there's many ways of physical constructing one.

The good thing is that because of how it's designed it'll actually receive the MilAir band fairly well at the same time - your close proximity to the airbase itself ensures there's no way things aren't going to be heard when you get not only a better antenna like this one you can make in 10-20 minutes at most once you have the parts together but even more so if you can get this antenna up in your attic. It doesn't require being mounted on a pole, specifically, it can just be set someplace in the attic where it's at a higher point than anything else. If needed you could even do this: add another inch or so to the length of the main vertical element and twist it into a loop to be used for hanging this 1/4 wave ground plane from a hook screw you put into a beam someplace in your attic so the antenna won't take up any direct space on the flooring of the attic.

Many possibilities to do this very cheaply and with vastly superior reception potential over the stock antenna and also saving you a ton of cash as well.

But that's just my suggestion - I'm not trying to take money away from the antenna manufacturers or the resellers of their products, it's just that sometimes paying such amounts of cash for something you can literally make yourself for a few bucks and be proud of it when it proves itself to be very useful is more rewarding to me I suppose. That's part of this hobby and doing it yourself more than anything else. :)

As for the mobile situation, I'm sure that antenna would be a nice choice but others will chime in on that soon enough, I don't even technically own a scanner anymore myself, I've been using SDR hardware and software for several years now but I monitor CivAir and MilAir just fine off my laptop. :D
 
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lmrtek

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WAY over priced antennas one and all!

You can easily make a 1/4 wave ground plane as described above

The discone antenna design works equally poor over a wide range and you can buy a hustler DCX discone for only 25 dollars if you really want to try one
 

SOFA_KING

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That is very good advice (build a ground plane antenna), and it will work better than the overpriced BS marketed "wizzbang" cure-all garbage antennas if the attic is not full of signal obstructing materials...or roof is not metal. But do yourself a big favor and use the lowest loss cable you can. There is no point in using cheap coax. Doing that will throw away any gains you made putting a resonant antenna up higher...and hopefully in the clear. You will be rewarded by using good coax.

And stay away from any "amplified" antennas. Your receiver is hot enough. An amp is not a good idea. It will cause more harm than good by raising the noise floor and introducing images.

Here is a good resource (and fun tool) to see how much you will loose on your frequency of choice with some common cable types.

Coax Calculator

Plug in the frequency, estimate the length, and see how much you loose. Any more that 0.5 dB is unacceptable in my book, but that's me. I use hardline on my Diamond Discone at 30' and hear so far away that it blows my mind. I calculate 0.35 dB loss at my favorite band. It's worth it!

Phil
 

dlwtrunked

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Welding rod (can be found at Sears and hardware stores) is great for making your own ground plane antennas. However for VHF aero, it may not be long enough.

Also, even though you are close, get the antenna as high as you can. Often that will be a factor more than anything else.
 

n5ims

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One important thing to remember when monitoring an airport is that it's very common to hear the aircraft in flight, but not hear the tower or aircraft on the ground. This is because in flight, they have a huge height advantage so it's easy to hear them for many miles. When on the ground, the same aircraft's signal will no longer have the height advantage and may not be heard much beyond the airport grounds.

Similarly, the tower is designed to be heard mostly by aircraft at altitude and those that are close by on the airport grounds. Their antennas are not designed to cover those on the ground but instead radiate the signal up and out to the aircraft. Don't be surprised if you can hear most aircraft OK but not the tower or those on the ground unless you live very near the airport.
 

br0adband

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The OP said he/she is 3.6 miles due south of the airbase so yeah, that's pretty damned close, practically just outside the fence line almost depending on the actual layout. Getting any antenna that's higher and not the stock rubber duckie will offer an improvement, I don't think any of us would argue otherwise on that aspect. Getting something in the attic, preferably near a potential window facing the tower of the airbase might even be better but again, because of the proximity to the base itself - slightly under 4 miles - should be fine with anything in the attic. Might even be possible to hang such an antenna out a window and improve things over the stock rubber duckie.

I think we're all in agreement for the most part: the linked antennas are very expensive and while they are quite nice to have they're not necessary in this situation. If the OP instead lived 30 miles away yes I'd say those antennas, properly mounted outside the home/house/etc and with decent coax as the feedline, would absolutely be better but, come 'on, barely 4 miles away, he/she should get booming signals from that range and I don't mean sonic ones because of the aircraft. :)
 

trp2525

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...I live 3.6miles due south of NASJRB Fort Worth. I am a total AvGeek...

I am looking for some recommendation...

Which one would be best?...
If the VHF-Air band is your primary interest Centerfire Antenna makes a nice VHF-Air 1/4 wave groundplane antenna that covers 118-136 MHz. It is nowhere near as pricey as the antennas in your links as it is only $37.95 (plus $8 Priority Shipping on any size order). They are made from heavy duty aluminum and stainless steel and as an added bonus they are made right here in the good old USA in South Bend, Indiana.

I agree with the comments above that you can fabricate your own 1/4 wave groundplane for less money than buying the antenna I mentioned. If you prefer one that is commercially made, however, I think the price from Centerfire is quite reasonable and their antennas are also covered by a "Limited Lifetime Warranty" (Warranty – Centerfire Antenna Mfg Co).

Link to the Centerfire VHF-Air 118-136 MHz antenna: VHF Special Purpose – Centerfire Antenna Mfg Co
 
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