The "Poe-Man's" Computer Radio

[crashbuilder]

So here’s what I’m thinking:

I've got a hitec neon 3ch radio with the dual rate and ATV (adjustable travel volume on ch 1,2 and 3) options installed. I want to use the radio to operate flaperons on my next sloper. I understand that a unit like the Digimix 2 (http://www.firmtronics.com/) or this thing http://www2.towerhobbies.com/cgi-bi...LXELT4&P=7#tech could be used to mix the throttle and aileron functions if I had one servo in each wing.

However I was was warned that the flap function should be on a self-centering stick / switch ..... you don’t want to flying with reflex or flaps by mistake.

The problem is that the neon has a slider for throttle control and it’s located on the back of the TX ... no visual way to confirm flap deployment.

The neon, however, does have an optional 4th channel ( 3 position switch) and all the channels are reversible by simply reversing the plugs that go into the circuit board inside the TX .........

So couldn’t I open up the TX, disconnect the throttle (ch 3) install the switch for ch 4 but plug it into the port for ch 3 .... then I can adjust the travel of the flap function using the ch 3 ATV and adjust the aileron travel using the ch1 ATV ........ workable?

Oh ...... the next big question: Is there some way to mod the TX so that flap deployment mixes in some down elevator

I know this seem like a lot of bother when I could go out and by a Flash 5 but the mods I’ve described (outside of the down elevator mix) would cost less than $20

[Comatose]

crash, the first should work, except that chances are its looking for an analog voltage, so make sure the switch pulls the signal up and down, not just short/open. The second, well, really at that point it isn't a neon anymore, it becomes a one-off job. That isn't to say it can't be done.

In theory, you could replace the IC that reads the potentiometers on your sticks, the switches, etc and then outputs those signals to the RF stage. This would be legal and then you could do whatever you wanted in terms of mixing or adding channels or whatever.

a midrange PIC like the pic16f873 would probably do the trick nicely.

[crashbuilder]

Thanks Comatose,
but it appears that I'm quite out of my depth, for instance what does: "so make sure the switch pulls the signal up and down, not just short/open"[/I] mean? As for the rest of your post ......? ... maybe I'll just add down trim when deploying flaps.

[jeffs555]

This would be legal
That is just not true. The transmitter is FCC certified as a whole, not just the RF section. Any modification at all unless permitted in the certification documents submitted to the FCC by the manufacturer are illegal.

That said, you are hardly likely to get in trouble with the FCC unless something you do causes interference to some other radio service. A plus side to the certification is that much of the schematics and service documentation required to be submitted to the FCC are available on line. Here is a link. https://gullfoss2.fcc.gov/prod/oet/cf/eas/reports/GenericSearch.cfm
Just put in the certification numbers from your transmitter. The schematics and other info for the neon, and most other RC transmitters are there.

Jeff

PS crashbuilder, just noticed your location, so I guess you don't have to worry about the US FCC.

[Marion]

jeffs555,

That's mighty interesting !! Wonder if I can find the schematic of my Futaba T6XAS ?? Do you know ??

[jeffs555]

Only way to know is to go to the site and put in the FCC ID number from the back of your transmitter. It might be a little old to be online. From my browsing, it seems like online documents are only available for equipment certified in 1998 or later.

Jeff