tewitt1949

I a few of these little berg 4 channel receiers and the antenna wire is about the size of kite string if not smaller. Anyways it don't tke much to break it or cut it. My questions:

1. How important is it that the wire is the same length? I would assume longer is better than too short. How critical is length?

2. I want to replace the wire but I can only find wire that is sligjhtly larger in diameter. Does diameter have any negitive affects?

I like the idea of using a little heavier wire as it will hold up better. but not if it will affect receiving the signal.
Thanks Terry

digital_trucker

Length is CRITICAL. The length of the antenna helps 'tune' the receiver. The gauge of the wire is irrelevant, except that heavier wire is, well, heavier. If you make it too long (or more likely, too short) your range will suffer, quite possibly with fatal consequences. That's why I love the 2.4 systems, really short antennae.

Anyway, that's why after a crash it's a good idea to check your antenna. It's happened that a crash can break it.

combatpigg

My Feedback: (3)

Terry, I could measure the length of the original if you like. If you solder it back together then range test it with cell phones at a great distance, it should be OK. I don't think the diameter is as important as the length.
I have been meaning to try the soda straw trick to totally conceal these stupid looking antennas. The idea is to neatly wrap a large diameter soda straw with the antenna and tape the winds down neatly and tightly. Pylon guys do it that way at 180 mph [X(]

tlrascal

My Feedback: (56)

Anteanna length is 1 meter, 39 inches. If you must shorten it do it in even divisions ie 19 1/2 inch but range will decrease. These are 1/4 wave and one meter is the length.

tewitt1949

Thanks a lot guys. I have several others that I can measure. Terry

vicman

My Feedback: (10)

I don't recomend doing any mods to it and just fly the thing. They work fine the way they are. If you don't like a little wire in the wind go 2.4.

tewitt1949

I don't mind the little wire, but its been spliced about 3 times and I would just look better if it had a new wire. I don't really want to modify it, but I was just wondering how exact I had to be on length. I will make it exactually the same length. Terry

combatpigg

My Feedback: (3)

I tried the coiled antenna off the Berg RX today and it worked OK. There wasn't anyone else flying and I didn't let the plane get too far away. It still needs a 1/4 mile range check with a helper to verify that it is working right. I'll go back to Darrol Cady's site to review how he does his.

BMatthews

The soda straw or flat plate winding trick can be used but it will reduce the range. Typically we have lots of range with any full range reciever so losing a bit isn't a big deal. Pylon racers may go 180 but they still stay relatively close to the pilot so that's why they can get away with coiling the antenna. And of course this also applies to much of our small model flying.

If you're one to fly at longer distances then I'd forego the coiling trick.

How you coil the wire is imporant as well. You don't want to just bunch it up in a wad and tape it together. You want a smoothly wound coil with a small spacing between the turns and then tape it so it can't bunch up and overlap. The coil can be either around a soda straw or other small tube or flat wound around a bit of thin plastic or wood. And I wouldn't wind up any more than you need to wind up.

Your results with the wire breaking suggests a good idea to me that we should all record the original length of our wire antennas so that we can replace them with the correct length in the event of an accident. The length is SUPPOSED to be a 1/4 wave long but I've seen a lot of variation in this so it seems that some recievers are base loading the wire with an added inductor or some other trick to shorten the length. So the trick would appear to be "don't assume" and measure before you crash....

BMatthews

CP, try range testing with the TX antenna down. Get a reading of it a it is now and then space the wire out evenly over the whole length of your straw as shown and recheck. If I'm right you'll see a small gain in range from that. I don't know if the fussing will be worth the gain but it doesn't take a lot of work to try it.

combatpigg

My Feedback: (3)

That's a good idea, Bruce. I just reviewed Darrol Cady's tutorial and he has about 3/8" between the coils.