I have just purchased a new antena due to snaping it at the air field. the guy at the lhs gave me one but it is smaller in diameter (which i new when i bought it)and is only a couple of inches longer than the broken one is it ok to use or can i still use the broken one. also because the smaller one wont snap into place can i solder a washer to it in order to keep it in place?


Thanks, Dave Trimmer

Dave,
if you still have the part that snapped off, I would recommend soldering it back together. Just carefully trim away about 1/8" - 1/4" of covering and then solder them together. Use just enough heat shrink over the splice to cover the wire and very slightly overlap the jacketing. Once you reinstall the receiver in the plane do a very thorough range check and make SURE that it checks out with the engine running. Also be sure that the solder joint is right, you dont want it coming apart on you. If you get the heat right and the solder wicks in you will be fine.

Even better than that would be to send the receiver back in to the mfg and let them fix it for you especially if it snapped right at the circuit board. Probably would not cost you but a few bucks and you would have a good as new receiver. I would not gamble with it, its your only link to the plane, if you dont get it right you are going to lose the airplane.

Are you thinking of the reciever because i'm talking about my tx sorry if I didnt say it.

Dave,
You really should have the correct antenna designed for your radio. The transmitting circuit is designed to have an antenna of a specific length, and by changing that length you will cause it to not operate properly. Either purchase the correct antenna for your radio, or send the radio in for service and have them replace it and then check your radio for proper operation.

Ken

Yeah I was thinking receiver. Ken is right on.[8D]

EXACTLY what transmitter do you have? Maybe we can find you the correct antenna. But if it isn't designed for easy removal/installation, consider the repair shop.

The antenna should be the proper fit in the TX case to prevent undue strain on the PC board or mount its attached to. Antennas don't "snap" into place. They are screwed onto a threaded boss or soldered to a PC board. The length difference bothers me, too. Is it possible the LHS guy sold you an antenna for ground frequencies (75 mHz)?

Dr.1

I have seen a "snap-on" type connector before although I can't remember the radio I saw it on. More typical in "rubber ducky" style.
They are usually BNC connectors due to cost.
http://en.wikipedia.org/wiki/BNC_connector
A variant of the connector shown above. I see them frequently in full scale aircraft usage.
I do prefer a more permanent mount for R/C use.

You're right. I've seen those on coax and CB/ham radios. Never saw one on a 72 mHz R/C radio, though.

Dr.1

Don't ya love search engines?

http://www.soaringspecialties.com/rubberducky.shtml

Looks like BNC connector on antenna. May require mod to radio.

Here's another:

http://www.smileyantenna.com/product...products_id=86

Go for the TNC connector option if you want one. Better connector.

I should note that I don't feel the range will be as good with a rubber duck antenna though and it is slightly more directional too.

http://www.hitecrcd.com/cgi-bin/ulti...c;f=1;t=001212

I have the airtronics radiant radio, i'm thinking of orderiing it straight from airtronics. just to make sure i get what works. or will those rubber duckey ones work, they look very small would they affect range, i'm taking some fairley expensive planes in the air so money towrds a better antenna doesn't matter.


Thanks, DT

When in doubt, do it right. Order direct or from a knowledgeable distributor.

Check out the August 2006 issue of MA page 135..

They have an article on the rubber ducky antennas complete with test results done by Berg..

the ducky lost 4-5db overall vs a whip but was LESS directional than a whip..

interesting result was a whip pointed directly at the reciever lost 25db (99%) of it's signal strength vs at 90deg to the reciever.

Just to clarify, you mean Model Aviation magazine published by AMA? I just looked online (don't have it with me) and didn't see article.

Dave,
I've got a Radiant myself, great radio. In fact, all I fly is Airtronics. I've sent many radios in for service and trust me, it's well worth it. In fact, I sent my Radiant in last year because of the very same reason. I had broken the last section of the antenna off. I sent it in for replacement of the antenna, plus the receiver had been in a crash. Anyway, they replaced the antenna, did a complete check of the radio including output test, AND cleaned it off completely (it looked new when I got it). They did this all for less than $50 (US). Trust me, the piece of mind you'll have when you get it back is well worth sending it in.

Hope this helps

Ken

When I was heavy into CB, I used both a 1/4 wave whip and a "Long Ranger", a triple-loaded 5-foot whip. I found out the loaded antenna (rubber duck) was much better for reception but not so good for transmission.

Another good fact to be aware of, never point the tip of your antenna at your airplane. That's where the signal is the weakest.

Dr.1

It's in the Pylon Racing Column

Yep, I found it. Those are typical "whip" characteristics but I'm just not personally familiar with "rubber ducks".