Old AM Radio & Serial Interface! - How to connect, any experiance?

[nadisha]

I have an old 3 channel AM radio (Kraft), I found the place where the servo timing pulse is coming before it goes in to the modulator. Checked the pattern with a Computer Sound Card Scope. If I take the signal from this point, will it work with the FSM serial interface?

I prefer the serial interface, as the parallel is connected to the printer, which I am bit reluctant to remove and fix every time I switch between flying and printing something. But is there any particular advantage of using Parallel interface than serial?

Thank you...

[Looee]

Hello Nadisha

I've posted a rather long post in the Ezone about my serial interface using an old Futaba T6FN that's working well with a straight connection to the serial port, (no circuit interposed), Look for it using the search function and the Title "FMS, whatever works" I'm not sure if my version will work for all old radios as I happen to have a rather low voltage out of my trainer port on the TX. Mine averages 6~7 volts and I think this signal needs buffering down to < 5 volts. I'm probably running this on borrowed time, but it still works great for 3 months steady use.

Looee

[nadisha]

Hi Looee,

I did check ezone, but I did not see anything related to FMS when I search for FMS! If you have this info, please send me by email. Thank you - Nadisha.

[Looee]

Hi Nadisha

The thread is now I know this is a huge URL but it's the most direct thing I've got to rewriting the entire post, as I don't know if the FMS forum allows url linking .

This may or may not work for you as my TX has a trainer port that happens to be the same socket that an old AT keyboard plugs into, as I used a scavenged keyboard cord for this..

Looee

[Mike Roberts]

Nadisha

You should have no problem using your old AM transmitter. As long as the signal is more than about 4 volts amplitude the FMS serial interface should work fine. I have made some 'tune up' improvements to the serial circuit. See my website under R/C Projects>FMS>Circuit Diagram

Mike
www.customelectronics.co.uk