Futaba Skysport 4 schematic / modification

[Guilherme_VM]

Does anyone has futaba's skysport 4 schematic.

I've one of these radios, but for 40Mhz band. I'd like to convert it to 72Mhz band.

I'll very glad if does anyone could help.

Guilherme

[imeins]

In about 30 seconds time you should receive the first "oh my golly gosh [sorry flanders almost let it slip there] the FCC are going to take you out and whip you till you die" response. This is obligatory here for anyone (from any country) who even suggests they might open the case of anything electronic. ;)

If you do find a source for circuit diagrams for Futaba gear then I'd be very interested in one for an old gold series 6 ch too.

Cheers, Ingmar

[Bruce Abbott]

You haven't put where you live in your profile, but from the words you chose I would guess you aren't from the US? If so then FCC regulations won't apply, but of course you should follow the rules in your country.

To change from 40 to 72MHz you need to reduce the capacitance and inductance of the tuned circuits. Unfortunately circuit diagrams don't usually include coil winding details, so you may have to experiment a bit (start by removing about 40% of the turns on each coil).

The best diagram I have is for a Skysport 7, but the Skysport 4 RF circuit should be very similar if not identical. Components that may need changing are C3, L1, C5, L2, C7, C10, L3, L6, C16, C17, L4, C19, L5 and C21.

For tuning you should have at least a frequency counter and rf power meter, or better yet a spectrum analyser. If you don't understand how to use these instruments and what adjustments are needed then I suggest you do not attempt the conversion!

[Guilherme_VM]

Thankk you very much Bruce.

It'll very usefull.

Don't worry. The regulations here (I live in Brazil, I'll update my profile) are very similar to that from FCC, but I'm an Eletronic Enginneer and licenced HAM.
I've a frequency counter, RF power meter and other equipments, Unfortunately not a spectrum analyser yet.

I feel more confortable having the schematic, rather than try and error technique.

Have you the receiver' schematic?

Thanks again.

Guilherme.

[flatfour]

These guys sell Futaba 4CH buddy boxes for $30. I realize getting it across the equator might be a bit of an issue...........

http://www.brucknerhobbies.com/Aircraft%20Radios.htm

[antonio carlos]

The best diagram I have is for a Skysport 7, but the Skysport 4 RF circuit should be very similar if not identical. Components that may need changing...

Bruce, I need the diagram/circuit from Futaba T4YF. Do you have it?

Thanks,