Futaba brown box transmitter conversion

[makoman1860]

Hi Guys,
A co-worker and I are building a pair of RC12E replicas for tearing around the office with. For fun I thought I would build up a vintage looking radio to go with it, so I picked up a nice looking Futaba "brown box" transmitter that was originally 72.320 mhz.....Im leaving that sticker on it just to freak someone out (probably only the old timers....). The plan is to install the workings of a HK cheap0 2.4ghz system in it. I would like to do the slot car controller mod and am looking for some really good pictures of one of the conversions. Anybody got one? Thanks!

[tamiyadan]

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[makoman1860]

Fantastic Dan thank you! My plan is to make new machanical internals to use the pots from the modern radio. I was also going to locate the trims and dual rates to pots on the top of the case and utilize vintage knobs. Basicly everything on the outside would look vintage (minus the short antenna), everything inside would be modern. For me CAD and 3D printing mechanical parts is more natural than electronics! I like the use of a control horn for a pivot mount. I take it the standoffs for the controller are mounted in the same locations as the screws that hold the handle halves together? Honestly I think the hardest part will be making up a nice voltage amplifier circuit to drive the original battery power meter since the 2.4 system runs off 4.8v and not 9.6v.

[tamiyadan]

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[jwscab]

Read up on analog voltage meters, there should be a shunt resistor across the meter and you scale the needle sweep with the shunt. Should just be a resistor change to rescale.

[marty slater]

on RCgroups in the radio section there is a few threads about converting old radios to 2.4
I sent a 1972 Kraft sport radio to Ivan an he converted it to 2.4 works great
all I know about electronics is make sure the batteries are in correct
marty

[makoman1860]

Read up on analog voltage meters, there should be a shunt resistor across the meter and you scale the needle sweep with the shunt. Should just be a resistor change to rescale.

I didnt see one on this, I was just assuming it was a cheesy " all or nothing" meter and they let the windings alone control it. Might be on the board though I need to follow the traces. My initial thought was a small IC based DC-DC converter and then use a shunt and trim pot. Like I said, the most work for the least gain! But that is part of the fun right?