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Author Topic: Radio Control Frequency Questions  (Read 3689 times)

Offline Aaron Little

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Radio Control Frequency Questions
« on: October 31, 2012, 05:42:48 PM »
Hopefully this is the right place, it does say open forum.

Are there any "banned" radios/frequencies?

Have an older Futaba Attack 4 that says AM-72 on the bottom.
Dad thought he heard they were banned but we don't know for sure.

Not wanting to stop spinning in circles but would like to try Radio, especially when it gets colder.

Offline Dan McEntee

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Re: Radio Control Frequency Questions
« Reply #1 on: October 31, 2012, 06:22:49 PM »
  As far as I know, all the old frequecies are still available to use. When things got narrow band after 1991, they took the old green and white/75.640 and made it part of the surface vehical frequency list, I think. Now that almost everyone is using 2.4 GHZ, there is a lot of good used equipment laying around that can be had really cheap. I just don't know if you will ever be able to get it worked on if need be. If it's cheap enough, it can just be disposable.  And quick email to the AMA or even your district representitive might be of some help. I have worked part time at a local hobby shop for 30 some odd years and just going by what I've seen and heard there.
    Type at later,
    Dan McEntee
AMA 28784
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Offline bill bischoff

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Re: Radio Control Frequency Questions
« Reply #2 on: October 31, 2012, 06:50:02 PM »
Only 2.4 ghz radios will be allowed in CL. If you plan to use it for "regular" RC flying, the radio must meet narrow band transmitting requirements. If your radio was manufactured after 1991, it is still legal. If it has the AMA gold sticker on the back or bottom, it's legal. This will be about 2" long by about 3/8" wide. If in doubt, ask an experienced RC guy. Some will say it is illegal simply because it is AM; this is false.

It is the immunity from interference and frequency conflicts that has made the use of 2.4 ghz radios possible in control line. With 72 mhz and 27 mhz radios, only one radio on a given frequency can operate at a time without causing interference for others. With 2.4 it's a non-issue. Think of old radios like walkie-talkies, and new radios like cellphones

Offline Aaron Little

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Re: Radio Control Frequency Questions
« Reply #3 on: November 01, 2012, 09:15:35 AM »
Thanks for the replies guys.
Looked on Futaba's site and it looks like this one is ok.
It was made in 1992.
It will be used for putzing around some with Radio control not for CL.

Offline Tim Wescott

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Re: Radio Control Frequency Questions
« Reply #4 on: November 01, 2012, 09:48:01 AM »
If you have trouble with it, the new 2.4GHz stuff has come way down in price for basic 4-channel control.
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline FLOYD CARTER

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Re: Radio Control Frequency Questions
« Reply #5 on: November 01, 2012, 12:27:47 PM »
Remember, it is not "illegal" to use older radio transmitters (not "narrow-band") You only have to worry about using them at an AMA sanctioned contest.
My R/C gear is on 53 MHz.  Wide-band stuff.  It is still legal.

Floyd
89 years, but still going (sort of)
AMA #796  SAM #188  LSF #020

Offline Tim Wescott

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Re: Radio Control Frequency Questions
« Reply #6 on: November 01, 2012, 12:33:18 PM »
Floyd, I know that applies to amateur-band stuff, but I thought the FCC pulled the authorization on the wide-band stuff for 72 & 75 MHz as part of a general rearrangement of that whole slice of spectrum.

Amateur band is different: I think there's a slice of spectrum for radio control on every VHF and microwave amateur band except for two meters and 70cm, and I may be wrong about 70cm being excluded.

If you're gonna recreate the RC glider flights documented in the October, 1937 QST, then you'll want to be on 6-meters, and keep your fingers crossed.
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline Chris McMillin

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Re: Radio Control Frequency Questions
« Reply #7 on: November 01, 2012, 12:35:04 PM »
Me too. Wide band is illegal as far as I know. This by FCC, not AMA.
Chris...

Offline Aaron Little

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Re: Radio Control Frequency Questions
« Reply #8 on: November 01, 2012, 05:59:58 PM »
Also looked at this, you get a new 4 channel transmitter and the software...
http://www.horizonhobby.com/products/phoenix-r-c-pro-simulator-v4-0-w-dx5e-RTM40R5510#t3

I hear that simulators are a great way to get your feet wet without the fear of destroying something.

Offline Jim Kraft

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Re: Radio Control Frequency Questions
« Reply #9 on: November 01, 2012, 08:13:43 PM »
I have two old JR PCM Century 7 radios that I bought back in the 80's, and had stickered when the narrow band thing came along. I have been flying them for years without problems. I am way behind the curve when it comes to R/C stuff. I flew Pattern competition for 25 years and quit in 94 when I started flying controline again. I don't fly much R/C anymore but I would not know what to do with a computer radio. Since most have gone to 2.4 I do not have to worry to much about interference.
Jim Kraft

Offline bill bischoff

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Re: Radio Control Frequency Questions
« Reply #10 on: November 01, 2012, 10:05:14 PM »
Do you want another one? CHEAP? Send me a PM.

Offline Dennis Leonhardi

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Re: Radio Control Frequency Questions
« Reply #11 on: November 01, 2012, 10:31:57 PM »
Also looked at this, you get a new 4 channel transmitter and the software...
http://www.horizonhobby.com/products/phoenix-r-c-pro-simulator-v4-0-w-dx5e-RTM40R5510#t3

I hear that simulators are a great way to get your feet wet without the fear of destroying something.


Aaron, this is an excellent simulator package - my son and I love it.  It will really help you at no cost in airplanes ...  I've had it for a few years, and love that the upgrades, once you buy it, are totally FREE.

I have quite a few electrics and use the DX5e transmitter with them - additional (Spektrum compatible) receivers for the small electrics cost me about $10 each.  You can hardly buy a 72MHz receiver crystal alone for that.

Talk to some of the RC guys down there, you're near some very helpful people.


Best to you and Bill,
Dennis


Think for yourself !  XXX might win the Nats, be an expert on designing, building, finishing, flying, tuning engines - but you might not wanna take tax advice from him.  Or consider his views on the climate to be fact ...

Offline Curare

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Re: Radio Control Frequency Questions
« Reply #12 on: November 01, 2012, 10:32:19 PM »
I know there's a bunch of guys on here who fly RC, *looks around*

Hehe, must be some kind of stigma on here about that :P

AS an RC instructor (and C/L rookie), I would suggest you head to an RC field and see if they have a club trainer. (most do), rather than messing around with archaic radios, get some first hand experience with a 'buddy box' and an instructor. You'll know in about 2 minutes whether you want to go further or whether you think it's overrated  ;D

Do yourself a favour and buy a radio that's compatible with your instructor, and has a buddy box port, this will save you from re-kitting your toys, a LOT.

Don't buy the cheapest radio, as you'll throw your money away if you chose to go on further, 4 channel radios are a dime a dozen and once you've bought one, it's worth about as much as a set of kinked lines.

Hope that helps!
Greg Kowalski
AUS 36694

Offline john e. holliday

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Re: Radio Control Frequency Questions
« Reply #13 on: November 02, 2012, 08:29:17 AM »
I too was an instructer with the local radio control club.   I know what kind of stuff people show up with to try and learn.   Radios that have not been checked.  Engines that have never been run.  And the planes, a couple  never made in the air until the person took them home to fix them.   Even if you have a radio that has been stickered, you still need to check it out.  I mean by range check, both with engine not running and with it running.   Yes the buddy cord was an improvement on the radios.  But, wait til you have a deaf/mute for a student.   He was a fast learner on the sticks.   Also as I taught my students, hold the sticks between thumb and index finger.   Too many people get in trouble using only the thumbs.   It keeps you from over controlling. 
John E. "DOC" Holliday
10421 West 56th Terrace
Shawnee, KANSAS  66203
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Offline FLOYD CARTER

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Re: Radio Control Frequency Questions
« Reply #14 on: November 02, 2012, 12:39:05 PM »
You can still order R/C gear on the 6 meter amateur band.  It is real easy getting an FCC Technician Amateur license.  No Morse code required, and the written test can be aced with a minimum amount of study (study guides are available).

I've used Amateur bands for R/C for at least 40 years.  I've never had interference problems.  At a contest, you can operate at will without interference to/from anyone else.  I just check the transmitter impound to make sure nobody else is on 6 Meters.

The only real advantage with 2.4 GHz is lack of interaction with other transmitters.  6 Meters has the same result.

Floyd
89 years, but still going (sort of)
AMA #796  SAM #188  LSF #020

Offline Bill Little

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Re: Radio Control Frequency Questions
« Reply #15 on: November 02, 2012, 01:10:53 PM »
The Attack 4 Futaba is all mounted in a model, and is available for use.  Never planning on using it in any type of "contest".  It is mounted in a RCM 20 trainer (how many remember that one? LOL!!).  I learned how to fly on it and it has had only minimal damage even though it is a tail dragger.  I only have one more R/C model left, a royal .40 size KI 61 Tony.  Aaron has never flown any type of R/C and just wants to try it.  ALL the clubs with in 100 miles are R/C.  Makes finding a flying site much easier!

BIG Bear
RNMM/AMM
Big Bear <><

Aberdeen, NC

James Hylton Motorsports/NASCAR/ARCA

AMA 95351 (got one of my old numbers back! ;D )

Trying to get by

Offline FLOYD CARTER

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Re: Radio Control Frequency Questions
« Reply #16 on: November 02, 2012, 03:01:28 PM »
Transmitted bandwidth is determined by the pulse width, pulse repetition rate, and the "rise time" of each pulse transmitted.  Since ALL transmitters use the same 1.0 mSec pulses, and nearly the same repetition rate, making a "wideband" "narrow" only requires a slight "rounding" of each pulse generated.  This can be accomplished by installing just one small capacitor in the pulse-forming circuit to roll off the sharp rise-time.  The tuned circuit after the RF final amplifier can still be "wide" because the spectrum being amplified is already limited in bandwidth.

F.C.
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AMA #796  SAM #188  LSF #020

Offline Peter Ferguson

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Re: Radio Control Frequency Questions
« Reply #17 on: November 03, 2012, 12:34:27 AM »
Just a recommendation so take it or leave it.
Don't waste your time and money messing with old R/C equipment. The new stuff is miles ahead , the batteries, servo performance are vastly improved . Your messing with old components like old wire, tx pots, switches, plus its AM . It is not even close to the signal reliability of the new 2.4 systems or even the now outdated FM dual conversion systems. Check the prices on the new stuff, its cheap and works way better.
Peter Ferguson
Auburn, WA

Offline FLOYD CARTER

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Re: Radio Control Frequency Questions
« Reply #18 on: November 04, 2012, 09:55:53 AM »
There are some folks out there who hesitate to toss anything that still works, or can be made better.

My Futaba FM gear is old, but still works perfectly.

(Oh yes. My main car is a 19 year-old Toyota. Still runs like new)

Floyd
89 years, but still going (sort of)
AMA #796  SAM #188  LSF #020

Offline Aaron Little

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Re: Radio Control Frequency Questions
« Reply #19 on: November 04, 2012, 11:14:30 AM »
Right now the idea is to use as much as i can to get my feet wet, see if I even like it.
As a single father sometimes I have to make do.

Offline Paul Smith

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Re: Radio Control Frequency Questions
« Reply #20 on: November 04, 2012, 12:18:54 PM »
Control Line is a good place to use illegal RC junk you can get for cheap.  Nobody knows one thing from another.  Use whatever you want.  It won't bother me.  Modern outlaw RCers use that binded 2.4 stuff.  You couldn't shoot 'em down if you tried.
Paul Smith

Offline Andrew Borgogna

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Re: Radio Control Frequency Questions
« Reply #21 on: November 04, 2012, 04:48:15 PM »
I do not believe that Futaba ever made a Narrow-Band AM transmitter or receiver.  So when the change to narrow-band took place all wide-band AM and FM transmitters were banned.  Note I did not say receiver because you could still use them with a new xtal to the new narrow band frequencies BUT you needed the clips for your frequency and the two adjacent frequencies.  Needless to say this did not go over well with the people buying narrow band equipment.  I was one of the people who had to throw away perfectly working radio equipment because it was wide band.  Funny thing is with the almost universal switch over to spread spectrum (2.4ghz) nobody is flying on the old 72mhz equipment meaning they are fairly safe to fly these days.  I still fly my narrow band 72mhz equipment today with no problem at all, but no wide band ever!  n1
Andy
Andrew B. Borgogna

Online Howard Rush

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Re: Radio Control Frequency Questions
« Reply #22 on: November 04, 2012, 04:53:44 PM »
...plus its AM .

I thought that Pete had misset his clock when he fell back, but I see now that he meant amplitude modulation.  Never mind.
The Jive Combat Team
Making combat and stunt great again

Offline bill bischoff

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Re: Radio Control Frequency Questions
« Reply #23 on: November 04, 2012, 05:07:20 PM »
I do not believe that Futaba ever made a Narrow-Band AM transmitter or receiver.

They did indeed make narrow bamd AM equipment.

Offline Hoss Cain

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Re: Radio Control Frequency Questions
« Reply #24 on: November 04, 2012, 10:03:38 PM »
Gentlemen:
    Please allow me to add some information to your interests in the RC world.
In the '70s there were seven 72 Mhz frequencies allowed for RC flying. 27mhz was available, however at risk. If near a highway or so it was not infrequently that your machine would perform a Lamshavock (sp. ? ) while the pilot was saying "I did not know I could do that!"  ;D   The CB radios took their toll of RC airplanes. 
AMA was working for more and better frequencies. In about 1980, the FCC offered 50 72 MHz freqs. for model airplane only use, along with other freqs. (channels) for ground vehicles. Then a hangup happened. Some lower level FCC persons hung on to the freqs. The AMA Frequency Committee Chairman ( name is found as Technical Editor for AMA in the MA mag.) and I, then the AMA Dist. VI DVP -not on the committee-  worked out something that the EC didn't like, but knew they should go along with. That was early November, 1981, and within a couple weeks the freqs. were released.
The 50 channels were released on a Phase-In plan to assist the industry to get production from a few wide-band channels to a lot of narrow band channels. FCC set the deadline as 1991. I don't recall the exact day, etc., but after that all new radio transmitters had to be narrow band. If you wished you could have your old one re-tuned, thus the sticker program. If you had a wide-band receiver in your machine, then you could easily get shot down. Your choice!  ~^

All clubs or groups needed a frequency board and much effort was expended these past 34+ years to that effect and still happens. I still fly 72Mhz as I have 3 excellent transmitters plus 7 others not so great, 2 being multi-frequency, and about 20 receivers, several multi-frequency. Not much problem as so few are using them. In today's world each has to have the latest item it seems so RCer spend fortunes on the latest radio, battery or super servos. They will pay whatever for the Latest[/b new item but P&M loudly about AMA and Club dues.
]I have a dozen super digital servos in a drawer. Never been used. Regular servos still work fine and don't waste a lot of power, as digitals do. I have 4  2.4 radio transmitters, 6 receivers, and they seldom get used. One unit is for night flying only.

You don't need 2.4 to enjoy RC. One scale writer in a now defunct magazine was fired because he wrote to the RC Scale community that there was no need for the big expensive digital servos being advertised as the ONLY way to fly. If you have to go that route on your CL model, you will also need a bigger battery than you need for a small 42oz. analog.
OTOH, if you are right next to an RC field, I suggest you check out their fliers for 72mhz. if within a 1.5 miles.

My RC Warbird model, Eiendecker,  my main entry at area warbird fly-ins for several years has 101" wingspan, fabric and dope, Zen. G-26 gas burner.  Flies well. No digital servos, Channel 51. Picture not accepted here. 
Horrace Cain
AMA L-93 CD and Leader
New Caney, TX  (NE Houston area)

Offline Andrew Borgogna

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Re: Radio Control Frequency Questions
« Reply #25 on: November 05, 2012, 12:29:34 PM »

"They did indeed make narrow bamd AM equipment."

It's been a long time but I don't disagree with you I just didn't remember it.  Most of the narrow band stuff bank then (at least the stuff that worked) were "dual conversion receiver" sets.  Getting the single conversion super hetrodyne equipment to hold to the 10Khz sizeband requirements  of the narrow band spec was a bit tough.  I remember having a chat with Phil Kraft on this very subject.  Anyway it's been a long time and my memory aint what it use to be!
Andy
Andrew B. Borgogna


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