8UAF problem; need help please

[LesUyeda]

Here goes.

I bought a used 8UAF at a swap meet last weekend, and channel 6 does not work properly. The receiver output is there, but fixed in width, not variable with the Ch 6 pot knob. If I mix to make any other channel the master and 6 the slave, 6 does not vary as the "any other channel".

If I make 6 the master, and any other channel the slave, the "any other channel" varies as the 6 pot knob.

I'm stumped as to what may be the cause.

I would really like to get a block diagram or schematic, but I feel that probability is quite slim.

I have my original completely working transmitter, and a scope and the rest of the equipment I need to trace and compare, but some documentation sure would be handy.

I am on the west coast, and there are no repair facilities out here, and I am loath to send the transmitter all the way to the east coast for repair. For the price I paid, and the kind of aircraft I am currently flying, I can live without channel 6 if necessary, but it would be nice to have a fully operational unit.

Les

[rc404]

Have you verified that there are no mixes active that involve chan 6? For example PMIX or Flaperon?

Ed

[LesUyeda]

Yes, Ed. If it were a program disable, channel 6 would not have worked as the "master". One of the first things I did was take my Compac, and copy all the models from my 8U that works to the newely acquired one.

Les

[rc404]

Yes, Ed. If it were a program disable, channel 6 would not have worked as the "master". One of the first things I did was take my Compac, and copy all the models from my 8U that works to the newely acquired one.

Les

Well for what its worth, I went through the service menus on my 8U. There is one menu called DATA RSET that I presume resets the memories for the models. I would be tempted to try this, but if you copied a working model from a CAMPAC and it didn't work, I wouldn't have a lot confidence that it will help. Just not sure what else to suggest.

You need a service menu enabler to get into the service menu. I built my enabler from info here

http://home.socal.rr.com/hotweb/futabaserv/

Ed

[rc404]

Actually here is a better description of the service menus. Resetting the control range for channel 6 using WIDE REVI and NARO REVI might fix your problem.

http://www.hansenhobbies.com/products/txacc/256k/radiomenus/info_servicemenus_8u.html

Ed

[LesUyeda]

Thanks Ed. I had seen the "enabler" thread once before, but it is really scarey. I know that the Compac's are interchangeable between the 8U and the 8U Super, but they don't talk the same language, and that scared me off, but in retrospect, if the pin outs are the same, it really shouldn't matter. In that channel 6 works properly as a "master", I really doubt that resetting the control range is the solution. Oh, well; onward and ?upward?.

Les

[rc404]

Thanks Ed. I had seen the "enabler" thread once before, but it is really scarey. I know that the Compac's are interchangeable between the 8U and the 8U Super, but they don't talk the same language, and that scared me off, but in retrospect, if the pin outs are the same, it really shouldn't matter. In that channel 6 works properly as a "master", I really doubt that resetting the control range is the solution. Oh, well; onward and ?upward?.

Les

I wouldn't be surprised if you are correct that resetting the control range won't help. I'm running out of ideas here. Does a PMIX with 6 as the master and 6 as the slave work?

Tony Stillman at Radio South (www.radiosouthrc.com) is an authorized Futaba repair center, and he is a really good guy. Perhaps an email to him explaining the problem is worth a shot. Maybe he's seen something like this before and can tell you if it is repairable.

Good Luck,

Ed

[LesUyeda]

Good thought Ed. I will have to try the 6 master 6 slave routine and see what I get.

I have e mailed Radio South before to find out about repairing a different 8U and never even got a response. That sort of turned me off.

Thanks again

Les

[rc404]

Good thought Ed. I will have to try the 6 master 6 slave routine and see what I get.

I have e mailed Radio South before to find out about repairing a different 8U and never even got a response. That sort of turned me off.

Thanks again

Les
Sorry to hear about your previous problems with Radio South. Would suggest you try again. There was a period of time where they were shut down, can't remember if it was fire or hurricane. No excuse, but they're pretty highly regarded in the pattern community. I've gotten pretty good service from them.

Ed

[LesUyeda]

Thanks, again Ed. I tried the 6 master 6 slave routine, and that didn't work either. I have an old broken 8U in the rafters, and I might just start playing with that to see what it is mechanically, and where things go; how many "house" chips there are; maybe I can develop my own block diagram.

Les