trainer radio mods (servo throw reduction)

i have this idea im bouncing around in my head.

i have a CHEAP radio i use for training (jr 4 channel) it has no dual rate function.

i have used a dual rate radio (for slave) and found this to be ideal for student (and instructor) safety.

can i modify the pots (ie add resistors or somthing) to reduce the servo throw?

this radio is never going to be used as a transmiter again (old am wide band) so why not make it a "low rate" training radio?

any tips or ideas will help thanks for reading ...

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Sounds like a plan, if you already know that the AM box is compatible with your newer transmitters, trainer-cord wise.

I dunno 'bout JR, but if Futaba can be an example the old AM transmitters use a different encoding sequence than the FM transmitters, and are incompatible unless you make an AM-FM conversion trainer cord or swap the signal leads around in the old AM box.

One of the things Futaba did when they converted my Gold Face AM transmitters to FM was change the coding sequence and swap the AM module for an FM module.

As for adding switched resistors, no reason that wouldn't work. If you use variable resistors of the proper range and mount them so they're externally accessible, you can vary the percentage of the dual rate function as needed. Cheers, Fred McClellan the dash plumber at mindspring dot com

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Fred McClellan

Don't know about the encoding sequence but I have heard also that they are incompatable. I have a Tower 4channel (Futaba Conquest I believe) that I added provisions for dual rate. Add a 25 k pot in series with the lead from the center of the existing stick pot and a switch to switch it out. Works for me. Good luck. Gene

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thanks the am jr and fm jr stuff are compatable.

ill look inside it on monday and keep posted.

any other input will be apreciated.

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I confirm what Jene said (wheelsdown@....) :

Just add a resistor to the middle contact of the pot of the stick of which you want to see the throw reduced. Eventually with a switch to bypass your "home made dual rate".


Reply to
Olivier tx2tx

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