Author Topic: need External/base station antenna ideas for a hand held aviation nav/com radio  (Read 30854 times)

Offline tomcruse7

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Hi I live a few miles off runway 23L at IND... someone already has quite a few feeds up for IND but regardless if I can contribute to the IND feeds or not I would like to have an external/base station type antenna set up for my icom a6 hand held. I am a pilot and understand the basics but defiantly not an expert when it comes to antenna and types that will work best. Basically I am in an apt so the height of an antenna set up would prob be 10-15 feet max. what type of antenna would give me the best reception for my droller with a shorter poll height? can I amplify the signal with a pre amp at all? thanks for your help in advance :)

Brandon



Offline notaperfectpilot

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I recommend a homemade yagi antenna...they seem to have a fair amount of gain, and is extremely easy/cheap to build. check out this topic here:

http://www.liveatc.net/forums/listener-forum/airband-yagi-antenna-designs/

hope this helps!

Offline InterpreDemon

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I would start with a cheap ground plane as high as you can get it, and that will probably get all worth getting on the ground at the field while still giving you 360 deg coverage of everything in the air. If you can't pick up tower, ground, approach or departure ground transmissions then you might consider adding a yagi to the side of the mast, but from a couple miles I think you will be fine. It's all flat around there, right?

Offline tomcruse7

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yes its flat i can pick up tower and app with the stock ant. fairly well... i was just looking for better recption. Are all the conectors cpmpatable or will i likely need an adaptor?

Offline tomcruse7

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i mean if i can go the lazy route and but something alrady made for 50$ or less i prob would

Offline InterpreDemon

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Being that you are going to use a transceiver instead of a scanner, it is a good idea to have a good impedance match just in case you accidentally key down, so a simple ground plane with 50ohm cable like RG58 or RG8x will work fine. Your connector on the radio is a BNC, on the antenna it may be an "N" type (if commercial grade) or a PL-259 if a cheapie or scanner antenna. If you don't have the skill set for dressing cable and soldering connectors, I would recommend a kit from a higher grade supplier that includes the antenna, pre-terminated cable of the length you need with the proper connectors and antenna mounting hardware. The problem with most cheap scanner antennas is that they usually are multi-band or, if mono-band ground planes are not long enough for the air band, being sold primarily for the VHF high band of 148-174. Ground planes cut for air band can be expensive due to more limited, usually professional suppliers, so the most reasonable option is often to buy a ground plane for VHF low band (30-50) and cut the radiator and radials down, the benefit being the elements are often thicker (giving you greater bandwidth with a good match) and the mount more sturdy.

For a simple "check book" solution I would go to this site:

http://www.wingsandwheels.com/antenna_vhf_airband_gps_mobile_e.htm

Call those folks up. All the antennas are air band, the Larsen they have looks pretty good for what you are needing, and they sell cable and connectors, probably could fix you up with a prepared cable as well.

Alternatively you can make your own stuff that would perform just as well for a fraction of the cost (like a couple copper welding rods and a PL-259 bulkhead connector), but without proper knowledge and test equipment your results may vary. But making and experimenting with antennas can be a great deal of fun, I have probably made hundreds of antennas and RF distribution systems over the years for all sorts of applications from HF to microwave, and once you start it can become addictive. One way or the other I would not recommend using any antenna or feed system that is not reasonably well tuned because unlike most others here you have a transmitter to protect, though most portables have circuitry that protects against broken or missing "rubber duckie" antennas. Even my VHF feeds, two of which use a real Narco NavCom with no chance of accidentally being keyed, have custom, perfectly tuned, pattern tailored antennas.
« Last Edit: January 10, 2014, 11:56:30 AM by InterpreDemon »

Offline tomcruse7

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I have SOME knodlage i can do the soldering etc but with the tech of what works with what im lacking. ya it might be fun to experament around with it some... or buy somehting cheeper and modify it....thanks again for the info :) ill look into it

Offline tomcruse7

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Offline InterpreDemon

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No good for transmitting on the air band, in fact not much better than putting a lawn chair on your roof and listening from up there with your hand-held.

Why don't you just build this one for less than five bucks:

http://www.hamuniverse.com/2metergp.html

I'll model it up on the computer and give you the element dimensions for 127 mHz (center of air band) or whatever frequency you want.

Offline tomcruse7

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ok ill give it a try.... but  i need an ant thats fairly good for all aviation com freq's 118.0-136.99 mhz as im not planning on listening to only one or 2. I would not have much need to transmit only recieve