PDA

View Full Version : Internal Antenna


BobT
2007.07.10, 02:04 PM
Running on my buddyís basement track we were having a problem with glitching every time we came close to the stairwell (see pic). There are several wires in the wall AC, speaker wires, outlets florescent etc.

http://img.photobucket.com/albums/v84/Bob_T/Mini%20RC/Tracks/DSCF3272.jpg

To alleviate the problem everyone was going to a longer antenna made from thin piano wire. I decided to take a different route.

Receiver antennas are tuned to the frequency band of the transmitter so you canít just make them bigger or smaller without using a little knowledge. You have to multiply the length of the receiver antenna as they are already tuned by making them a multiple of the actual wave-length of the transmitter. Antenna wires twice as long as the stock antenna can start to influence the carís handling in a negative way so I went internal with mine.

http://img.photobucket.com/albums/v84/Bob_T/Mini%20RC/MiniZ/antenna.jpg

My antenna is 3 times the normal length without hurting handling and is now zero glitching.

TALLGEESE
2007.07.11, 05:36 PM
Bob, that's a pretty good idea, I used to have glitching issues on my basement track a long time ago.. We actually tried out one of the Kyosho internal antennas and that just made the problem worse.. It looks like you've got it fixed though.. I never thought about increasing the length of the factory antenna wire like that.. Pretty innovative.. That's a pretty big basement track you've got to run on, very nice..

herman
2007.07.12, 02:52 AM
ah... master bobt... aka the gray ghost... it's been a long time... you were one of the first guys i kinda looked up to back in the day...

anyway... once again pardon my ignorance... but what is the actual length of your internal antenna... what other "lengths" can you have your internal antenna without your car glitching on you?

Receiver antennas are tuned to the frequency band of the transmitter so you canít just make them bigger or smaller without using a little knowledge. You have to multiply the length of the receiver antenna as they are already tuned by making them a multiple of the actual wave-length of the transmitter.

if i got it right... what are the multiples of the actual wave-length of the transmitter?

idreamz
2007.07.12, 12:24 PM
Cool. I'm also interested in the antenna lengths. Do you have to give it a special winding?

Now I don't want to hijack your thread or so but since you're expert on this I have to ask if you can put two 27MHz AM transmitters through 1 antenna?

The reason I ask is that I wanted to build a car with some extra functions, and getting a 4ch spoke radio would be too expensive and awkward. So I thought about combining a wheel-style radio with a cheaper RC toy transmitter.

hrdrvr
2007.07.12, 02:16 PM
BobT, do any of you guys run ma010s? Have you/they tried out your under the body antenna? I assume you are using cat5 wire, which I tried. I made sure to get it the proper length for tuning and it works awesomely on my MR02. On the ma010 though, it glitches like crazy, and is totally undrivable with other cars around (within 5' or so).

We race in the back of a metal bulidng and there is a welding shop adjacent (many rolls of copper wire and 220v electricity) so we have all kinds of interference/glitch problems that we are trying to find a fix for.

BobT
2007.07.12, 03:24 PM
Herman,

My world has been turned upside-down for the last few years. Its good to be running my Zs again.

Wow! lots of questions, where do I begin?

Antenna length: I used about 60 centimeters or just short of 24 inches. I just used a stock antenna and kept increasing its length by multiples of the stock length until the darn thing stopped gliching. Oh and make sure your tranmitter antenna is fully extended. I actually noticed a difference. If it was not fully extended I'd still glitch.

Right: multibles of the actual wave length.

Special wind: No. Just insure that the wire never crosses itself. Start from the center and make the next oval just large enough to clear the last one.

Two Transmitters through on antenna? No. If you need 4 channels for your project use a 4 channel transmitter or two 2- 2-channel radios on different freqs and two coresponding receivers.

Yes its a nice track. Gary bought 250 interlocking foam squares from Johny Throttle when it closed. It had a interesting layout but was too technical for some of our newer drivers. So we took out some of the tighter section.
Gary has several of his friends and co-workers over and we supply them with our cars to get them interested in joining the Z bangers.

Gary has an MR-010 and so do I. We let the new guys run it. With no hop-ups its very neutral and easy to drive. Mine seemed to break every time I ran it. So I packed it away and run my MR-02MM and RM. I have several MR-01s also.

The wire is just very thin wire we carry in the train section of the shop. Its almost as thin as servo wire. It is imported/distributed by Model Power and is called "Rainbow Line". Its made in China for Model Power. Its nothing special just very thin stranded (very flexible) wire.

herman
2007.07.13, 02:49 AM
My world has been turned upside-down for the last few years. Its good to be running my Zs again. oh... i hope everything is ok now... it's nice to hear from you again... :D

and thanks for all the replies... :D

BobT
2007.07.13, 10:25 AM
Herman,

Thank you. I went from the worst time in my life to a wonderful time in my life.

I lost my wife of 29 years to a heart attack. My friends and family kept me going through the lowest times. Then an old grade school friend introduced me to a wonderful woman who lost her husband (31 years) just 5 weeks after I lost Patty. We shared our pain, our stories and now we share our lives.
http://img.photobucket.com/albums/v84/Bob_T/Auclair/948b7991.jpg
This is Judy.

idreamz
2007.07.13, 04:19 PM
Thanks for the answer. I'm going to skip my crazy idea and try an internal antenna.

And sorry to hear about your loss but I'm glad you seem to have recovered.

herman
2007.07.17, 09:40 PM
hi bob...

apologize for late post... and to be a bit off topic...

sorry for your loss... but, as always i believe in happy endings :D
nice to hear you're back...

marc
2007.08.13, 10:27 PM
Hi there bob, I lost my mom due to breast cancer back in March this year. So I know how it feels. Mini-Z racing was a good lifter for me. Of coarse, I went overboard buying Mini-Z stuff due to depression, but that's pretty much over now to some extent. Anyway, I feel your loss.