Author Topic: Used Cessna antenna as a base antenna?? (Read 41133 times)

NelsonC · « **on:** July 13, 2006, 00:14:34 UTC »

Hi guys, I'm working on my PPL and have just started getting into scanning. I recently was given a Maycom AR-108 handheld scanner. I've also purchased a Watson W881 handset antenna and a Workman magnet antenna for the car.

Now I'm on a mission to get this thing setup at home. I started to cut the pieces for a J-Pole (I live in Brampton and want to pick up 121.3 as well as much atc from Toronto/Pearson as possible).

It occurred to me that maybe I could just get a used (new is like $400) antenna off of a Cessna.....

I think that these are grounded on the chassis of the Cessna but I could mount it on a metal plate and then ground that plate (run a wire to the cold water line outside).

Has anyone tried/heard of this??? Am I better off with the J-Pole???

thanks,
Nelson

FlyCMI · « **Reply #1 on:** July 13, 2006, 01:43:45 UTC »

I personally think you would be better off with a j-pole specifically cut to that frequency. A jpole should be much longer than a C172 antenna. I'm still building mine, I'll post to let you know how well it works.

NelsonC · « **Reply #2 on:** July 13, 2006, 02:18:11 UTC »

Hmm...I keep thinking that maybe the Cessna would be better because it would be built to aviation specs....but maybe your right

I have actually cut the pieces an assembled it dry (not sodered) just to try out but it kind of...sucks. After hearing all the good things about J-poles I was disappointed but maybe I have to actually fine tune the lengths and soder everything together.

I was hoping that someone had tried this before because I would prefer a more stealth/smaller antenna like the Cessna (I already have 3 small dishes and one 10 foot dish on the roof!).

PS. I actually already hear alot in my room (second floor) with just a long piece of wire touching the original antenna. I hung the wire virticaly from the top of my window blinds and the tip touches the top of the handheld antenna. Some come in ok but most, including the ones I really want have alot of static.

KMSY · « **Reply #3 on:** July 13, 2006, 02:23:20 UTC »

Maybe the quality of the antenna is better in the Cessna antenna. I couldn't try it, but maybe if you get it really high, it would suit you well. But otherwise I would go with a J-Pole (price & a trusted method). Then again, I've never seen an aircraft antenna up close and don't really know what they're capable of.

I was disappointed with the quality I was getting out of my J-Pole by KB9VBR (http://www.kb9vbr.com/products.htm), but with some adjusting and fine tuning it now works perfectly.

Jason · « **Reply #4 on:** July 13, 2006, 02:26:59 UTC »

Quote from: NelsonC on July 13, 2006, 02:18:11 UTC

Hmm...I keep thinking that maybe the Cessna would be better because it would be built to aviation specs....but maybe your right

You can tune the J-pole to 125 MHz which will likely bring you good/great results (tuned to air band). I personally have no clue what you'd get with the Cessna antenna because I've never tried it.

Also keep in mind that the Cessna antennas are built and installed to certain specifications to make receiving and transmitting at altitude possible. It may not work so well when you're far away from the field and aren't too high above the transmitter.

I'd prefer the J-pole simply because it is a LOT cheaper and many people (including myself) have had great success with it.

Regards,
Jason

NelsonC · « **Reply #5 on:** July 13, 2006, 02:51:58 UTC »

Sounds like the J-pole is the way to go just have to be patient.

I maybe able to get a used "CI-109" cessna antenna for around $50-$70 Canadian. Not sure if I should try it or if I'm throwing my money away?

KMSY · « **Reply #6 on:** July 13, 2006, 03:09:58 UTC »

Maybe it's the next best thing! Nobody else has tried it. I think maybe if you get it up to about 40-50ft. it would work with no problem.
Someone with more experience with aircraft antennas would help.

NelsonC · « **Reply #7 on:** July 13, 2006, 03:26:23 UTC »

Well, I think that for $70 bucks it maybe worth a shot (not sure how high I can get it though...I'm thinking on the highest point of the roof..chim.) if it works I'll let you quys know....would be nice...it's less than 2 feet long

I'm going to try and tinker with J-Pole just because I want to see my own home made antenna work...and I have to wait to get the antenna anyway.

P.S. keep comments/suggestions coming...this website is pretty cool...when I mention this stuff to freinds they look at me like I'm speaking some alien language.

Lezam · « **Reply #8 on:** July 13, 2006, 12:13:53 UTC »

There was one on ebay that just sold for $30

FlyCMI · « **Reply #9 on:** July 13, 2006, 13:48:38 UTC »

I don't really see how a cessna antenna could work that well. It's a lot shorter than a homemade Jpole. It probably requires a ground plane to be on to work well to. If you ever take a CB antenna of a car and try to just transmit by using the mobile antenna, it barely even works. A jpole made out of copper fined tuned to the aviation band would work better if built properly in my antenna, but who knows a Cessna antenna may work better.

FlyCMI · « **Reply #10 on:** July 13, 2006, 13:51:45 UTC »

Heres a link to a cheap one on ebay. I don't know if it's for VHF radio though or for the avionics. http://cgi.ebay.com/ebaymotors/Comant-CI-121SP-6-Loran-antenna-avionics_W0QQcmdZViewItemQQcategoryZ26436QQihZ016QQitemZ260006401652QQrdZ1QQsspagenameZWDVW

Jason · « **Reply #11 on:** July 13, 2006, 15:07:34 UTC »

Quote from: FlyCMI on July 13, 2006, 13:51:45 UTC

Heres a link to a cheap one on ebay. I don't know if it's for VHF radio though or for the avionics. Ebay Link

It's a LORAN-C antenna, not VHF. It's not going to do you much good for the airband since LORAN-C operates in the low frequency 90 to 110 kHz band.

Jason

NelsonC · « **Reply #12 on:** July 13, 2006, 18:29:23 UTC »

Hi guys thanks for the comments. I really am going to try hard to make this J-Pole work but how much tollerance...how perfect does the measurments have to be?? I want to tune it for for 124MHz. My local club is Brampton and is on 123.3. I want to pick them up as well as Pearson and City Centre (the more I pick up the better but these are the main ones).

I used this website to make mine....is this right?

http://www.hamuniverse.com/jpole.html

Lezam · « **Reply #13 on:** July 13, 2006, 22:50:38 UTC »

Use them exactly, dont mess up any measurements..

Ronski · « **Reply #14 on:** July 16, 2006, 20:58:18 UTC »

I'm interested in this J-Pole and I am going to make one.

BUT, how does one decide on the frequecy to use to determine the measurements?

Air band is 118 - 138. and then there is the military band.

Can someone please enlighten me? I'm no techie, just a scanner user.

Regards.

FlyCMI · « **Reply #15 on:** July 16, 2006, 21:07:24 UTC »

I made mine set on 125 MHz. Search the forum for J-pole. Jason posted directions on there on how to make one. I finished mine just a couple of days ago, and I couldn't believe how expensive copper has gotten. For a 10 foot roll it was $20. I'll have about 35 bucks in this antenna. I haven't got a change to test it out yet because I don't have any wire.

NelsonC · « **Reply #16 on:** July 17, 2006, 01:22:54 UTC »

Well to determine what frequency to cut the J-Pole, you should probably pick one thats close to the main ones you want to listen to...check the closest airport and lets say they use 118 to through 129 and they don't use any more. Then what I would do is 118+129=247 then divide by 2 and you get 123.5 as the middle and tune/cut to that.

If you just want the middle of the aviation band then just add 118+136/2=127MHz...you still will get all the frequencies if you tune to one but the one you tune the pole to will be the strongest and then as you go lower or higher the signal will get a little weaker.....at least thats what I understand.

Ronski · « **Reply #17 on:** July 17, 2006, 19:29:27 UTC »

NelsonC and FlyCMI,

Thanks for your replies.

That will help me to get started on making my first J-Pole.

I'll let you know the results.

Lezam · « **Reply #18 on:** July 17, 2006, 21:10:54 UTC »

Quote from: Ronski on July 17, 2006, 19:29:27 UTC

NelsonC and FlyCMI,

Thanks for your replies.

That will help me to get started on making my first J-Pole.

I'll let you know the results.

Be careful... Dont burn your fingers off plz

Remember, use flux! Thats the magic word!

Ronski · « **Reply #19 on:** July 18, 2006, 20:15:16 UTC »

Wilco

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Author Topic: Used Cessna antenna as a base antenna?? (Read 41133 times)