Here a lot of guys use a standard air tx and hang it off their belts on hooks. They use them for scale planes and electric planes. The rx controls everything except the elevator that way they can install retracts,flaps, lights, rudder and ailerons for slight wind trimming , ETC.You could use a Tactic $40 2.4ghz tx 4 ch used on the micro planes from Hobbico and bind it to their rx's easily.
Just a thought
3rd line, more line drag. I'll investigate the Tactic rig, already have a Tactic 650 and a couple Rx units, but I was thinking car radio with squeeze trigger would work, and I could always go nutz and use the 2nd and 3rd channel for extras.
I've gotten away from the 3 line unless it is for throttle and not on an aerobatic plane. Even then I like to have the tx control the throttle so I don't have to hold the trigger. Lots of guys use them for carrier leaving only the elevator for control by the lines. The TTX650 is great in that you can program any rx output term to any channel stick. I have one my self and LOVE IT! Is it a scale plane or an aerobatic plane or other type?
Just about everyone has dropped the 3 line systems in favor of using RC or modified RC to send the signal down insulated metal flying wires.
Less drag, higher reliability.
The modification I would recommend is to make handle that you can move the TX electronics into, essentially cutting the TX case a bit and adding control line mounts to it. You'll have the trigger right there on your flying hand's index finger. You can change the spring centering "steering" wheel into a variable "dial" (flaps or some other options can use this) by removing the spring and adding something to have it hold position when you take your fingers off of it.
3 ch RC + CL = 4 function control... no rudder or aileron needed so its a "full house" system. Elev, Flaps, Throttle and Retracts for example.
Depending on the contest... (if you fly contests) you may want to look up how to disable RF and pass signal down the control lines. If not flying contests you can just go ahead and leave the 2.4 ghz signal.
You aren't going to worry about range... even the cheapest 2.4 ghz based car RC system will have 10X the range of your flying wires. So any that you can find should be fine. Its mostly a question of how hard it will be to add the CL wires to the TX.
You can fairly easily move the battery to a belt pack with a long heavy (18 gauge lamp cord will be great) wire to take some weight off of your hand while flying. 8 cell AA could make your arm tired pretty quick if you leave the TX batteries in the TX case.
propnut48 - "other" as in basic fun CL rig, like a baby flite streak, or a neat rig called Mirage (OZ plan) and maybe a baby ringmaster. All my motors are small (180-300) so plane will be small unless I get the giggles and decide to go for a wide open stunter.
fhhuber - Exactly ! Yes indeed, a spring loaded to zero squeeze throttle is what I have in mind. I forgot about the battery but I have enough serious wire and connectors laying around I should be able to cobble together a remote pack.
No contest to worry about - hardly any flying activity in my area save for gung ho warbirds. My first love, free flight - nothing. Probably have to drive more'n half a day to try out ALES glider comp.