baseload antenna

[talonxracer]

I have seen several baseload antenna setups, but I have had bad luck with deans antennas and was told to steer clear of the azaars. My question is about a simple home made one using a 1.5microhenry choke/coil. I have been to several local electronic shops but no one has a 1.5. Can anyone steer me towards someplace to get one? THNX

[vintage1]

Radio shack?

I see these sorts of things on ebay occasionally.

[Bthree]

Without the benefit of a grid dip oscillator or any other test equipment how do we know what a 1.5uH choke is going to do, how much length do you chop off an antenna ?

A Jeti RX for example has what looks like a 6.8uH choke and a <500mm long antenna lead. Any charts or tables on this ?

[talonxracer]

This is where I got the ideawww.uoguelph.ca/~antoon/gadgets/flywire.htm

[vintage1]

Actually, its not too hard to pickup the audio from a cheapo receiver, and use that as a crude aid to tuning.

But the best method of all is to mae up a bench, but the receiver and antenna to test on it, and, using retracted TX antenna, walk way till the servos buzz, and stick a pole in the ground.

You will very quickl;y work out what combos are working.

As an aside, if you disassemble any radios that have VHF etc, you generally find some chokes in there, or you can try winding wire round any bits of ferrite you find in there - slugs from IF transforners etc. When you get it near enough right, dip the final wind in epoxy.

[Lomcevak]

www.digikey.com

[ZAGNUT]

part # M8015-ND at digikey. $1.19 each or 10 for $9. have been using the "flywire" design with no probs for a couple of years now


dave

[talonxracer]

thnx for the link and info!!!

[Kwok_Yu]

Zagnut,

Are you using this on a plane or heli?

[ZAGNUT]

only on planes, from 1/2A to gassers.

don't know if it means much but all my recievers are full range and dual conversion, not the little park flyer cheapies. range check with fully extended Tx requires a helper with cell phone....

i also don't think there is any differance between the "flywire" and the standard azaar antennas.


dave

[vintage1]

Two things:

Any short antenna will not be as good as a long one.

Though loading helps by tuning the antenna so it appears 'bigger' than it really is, there is no one size fits all solution. Some receivers and some shortened antennas don't work well together.

Solution is to test and try. Range checks are pretty definitive answers to the question of whether you have a good combo or not.

[ZAGNUT]

Two things:



Solution is to test and try. Range checks are pretty definitive answers to the question of whether you have a good combo or not.

that's exactly why i tried a real range check with a fully extended antenna. i don't really know squat about RF but i ASSume that if i get great range over ground with various obstacles (fences, trees, power lines) along the way the range in the air should be as good or better.

dave

[Kwok_Yu]

Zagnut,

Thanks for sharing your experience. That's exactly what I wanted to find out. That is, if one should expect reasonable good range.