I just recently picked up a FP-T7UAO transmitter and PCM receiver with servos and charger like new still in box. I know this is a fairly old design but appeared to be in pristine shape except that the batteries were suspect so I replaced them with new batteries. After charging the batteries and connecting all together things seemed to be working fine. However, when I tried to program in dual rates or expo the three switches that switch from hi to low do not seem to have any effect. When I try to set different throws for the hi/low rates, the programmed changes (when I change it with the + or- keys, both hi and low switch positions follow the latest inputs. By that I mean that if I have the high rates set at 100% then throw the switch to the other position and program the new rate to 50% both the high and low rates are now at 50%; i.e. no change when I toggle the rate switch from high to low. This occurs on rudder, elevator and aileron rate switches. I have other Futaba transmitters that program in the same manner and all work well so I am reasonably sure I'm properly programming the unit. Any suggestions on what may be wrong or what I may be over looking? Thanks

More info, I played with this transmitter a bit more. On the rudder channel only, I can program two rates for the dual rate and I can program exponential on all 3 prime channels. I can program the PMix okay to put one aileron on Channel 7 with the other on Chanel 1. Now, I have an FP-T7UAF also and it programs correctly. The FP-T7UAP instructions are the same so I'm now sure I am not causing the fault. The problem seems to be associated with the three dual rate switches (rudder, elevator and aileron) Any advice would be appreciated.

As you know, the rates set should not change when flipping the switch. My first thought is that there is an internal problem from the switch to the main board on this old radio.

You might want to contact Radio South and see if they can take a look at it for you.


Sincerely,
Krysta
Product Development & Support Specialist
Futaba Service Center USA
[email protected]

I played with this a bit more and, after many flicking of the switches, they suddenly started working. At first they would occasionally switch but after may cycles, all three work now all the time. This radio was purchased in Dec 1990 and sat unused ever since until I got it from the original purchaser. It is on 6 meters (plug in module so could also be used on 72MHz modules). I got it because I also used to fly on 6 meters (N4MCZ) and decided to try it again. If it continues to work okay I'll put it in a scratch built 1/4 scale Moth I've nearly finished. Even if this is a couple if decades old, I still think it is one of the better units ever made and since it is PCM, should still be quite free from interference from most electrical noise. Edited to remove remarks where I miss remembered a name, mixed up Krysta with AnnMarie. Sorry, old age is ruining my memory.

Hello,
  The fact that the switches were not working at all at first, the transmitter is telling you something. There was probably corrosion on switch contacts after sitting unused for so many years.
  I would not use that radio in anything that I cared anything about, especially a scratch built model. The only way you are going to know for sure about the radio is to have a few hundred successful flights with no problems.
  The fact that something did not work at first, probably due to corrosion, something else could go wrong and likely at the worst possible time and it would be a shame to find out the hard way that well I guess it didn't work, when you go to pick up the pieces of your scratch built airplane.
  I had a Super Seven radio, still do, that I did not want to risk on a new plane so I bought a new T7C 2.4 radio. Electronic and mechanical devices do not like to sit unused. Switch contacts, potentiometers, etc are all suseptable to corrosion. Use at your own risk.
  Just my 2 cents and only an opinion.

The Pamster