stunthanger.com
Speed,Combat,Scale,Racing => Scale Models => Topic started by: Ed Prohaska on March 16, 2017, 10:20:12 PM
-
Here's a quick & dirty question: If I wanted to use a radio in a C/L scale model does it have to be 2.4gHz? Is there any reason it can't be a "legacy" radio from the "old days" like an Attack 4 or Conquest 6 on 72mHz? I see many of the old radios listed on eBay (some NIB) and they sell. Are people just buying to collect them or are they still legal to use? Just asking ... Ed Pro ...
-
They are legal to use for RC flight as the frequencies are still blocked off for this purpose.
I do not know if they are permitted in contests.
Higher end "computer radios" can feed out to a module that will talk to new rx. Some take an internal module even! A couple years ago I bought a Flash 4x, and a Flash 5 to give with my old Flash 4x to my brothers and Dad for slow electric RC trainers. I also had a handful of modulated RX. Shipping cost more than the equipment!
Phil
-
RC systems were not allowed for any CL functions in contests prior to the appearance of the 2.4 MHz systems. One of the logical reasons for not allowing such systems was to not have any interference problems with other CL fliers as well as preventing interference with possible other "regular" RC systems in the area. If such systems were to be allowed in a CL Scale contest, it would be necessary to have some sort of frequency control process as in RC contests. With the advent of the 2.4 systems, such interference with other systems, CL and/or "regular" RC models, is no longer an issue when using those systems.
The CL Scale rules now allow "The use of 2.4 GHz radio control signals through the air ...are allowed for other than pitch control except for restrictions outlined in CL General Rules."
This rule allows the use of 2.4 GHz systems and nothing else.
Non 2.4 GHz systems are not allowed in AMA sanctioned CL Scale contests. Now, if you want to hook up any other RC system to your model for non-contest flying, there is nothing to stop you. Beware that you might encounter interference whenever you fly.
Keith
-
I agree with the explanation of the rules.
If you use an old radio, you will only interfere with other old radios, which are rare.
On the practical side, I bought my 2.4 TX for under $40 and a batch of RX's for $4 each. So just get legal don't worry about it.
I bought out a batch of old RC models at an estate blowout. I think I can simply plug in the 2.4 RX (at $4) and get into the modern age.
Current technology is many times cheaper & better than the old.
-
The AMA flying site in Muncie only allows 2.4 Ghz for the Radio Control events, I have even heard of local clubs outlawing the older 72 Mhz systems because of the problems it caused. RC Contests would impound all transmitters to keep problems from happening.
I switched all of my aircraft (CL scale) to 2.4 Ghz quickly as possible back in 2013
Fred
-
They are legal to use for RC flight as the frequencies are still blocked off for this purpose.
I do not know if they are permitted in contests.
Higher end "computer radios" can feed out to a module that will talk to new rx. Some take an internal module even! A couple years ago I bought a Flash 4x, and a Flash 5 to give with my old Flash 4x to my brothers and Dad for slow electric RC trainers. I also had a handful of modulated RX. Shipping cost more than the equipment!
Phil
Legal: I'm pretty sure that for CL you'd want to use the 75MHz car radio frequencies. For RC, 72MHz is still legal (and that's what I fly with).
Contests: The rules specify 2.4GHz. I believe the rationale is to avoid having to deal with transmitter impound.
Practical: For $20 you can get a 2.4GHz 3-channel car radio from Hobby King that gives you throttle and a click-switch that would work for landing gear or 2-position flaps. With some modifications you could use the steering channel for something, too. Aircraft radios are not much more.
-
When considering Legacy RC transmitters / receivers you also need to be cogent of the fact that 52Mhz systems require a FCC Amateur Radio License.... and ALSO that many of the very older 27 Mhz, 48Mhz, and 72 Mhz legacy systems must be modified (if possible) to current FCC standards...The reason and process is beyond the scope of this topic
The C/L community, requiring 2.4 Ghz systems, was a sound decision for many reasons---
As others have noted, it is exceedingly cheap and easy to get the requisite 2.4Ghz system for C/L use
There are any number of 2.4Ghz RTR cars under $35 that have both the TX/RX, and servo to use as throttle control
-
Many older 72 mhz TX'ers are module based. These can be easily converted to 2.4. Otherwise, I am not sure why you would want to use anything other than 2.4.
-
Another thing to think about is that the newer transmitters have greatly improved the features that can be done including model memory, end point and mixing that may or may not be in the older transmitters. My Tactic 850 transmitter can adjust the speed of the servo if used it for flaps. While my JR radios worked just great using the DSC functionality for the down the line electronic controls the added features the Tactic 850 has are worth the money. Going wireless with the 2.4 Ghz makes flying with multiple models much easier. I use one traditional 8 channel transmitter for multiple airplanes and use model memory to store the settings for the toggle switches, end point, servo speed, servo reversing and other settings.
Fred
-
Don't forget the 3 inches of antenna (well, actually much less, but long antenna are about 3 inches) vs 30 or so inches of antenna.
Phil
-
Even the cheapest 2.4 works well. It only needs to cover 60 ft.