This is a "standard" engineering procedure for trouble-shooting
anything, using the technique of discrete component replacement. Your radio
control problem must be reproducible, of course. You've got a real
problem if it is intermittent, so do your best to get it to occur reliably.
- List all possible causes of the problem, such as faulty servo, faulty Rx,
badly-placed aerial, weak Tx signal, dodgy crystal, and so on.
- Work through the list of suspects, one by one.
- For each suspect, replace the part with a good part known to be working
fine, or change the situation as appropriate.
- Only ever make one replacement or change at a time.
- Test the system with the replacement or change. Ensure your test covers
both "normal" operation, and off-nominal operation. That is, while
checking that it works when you'd expect it to work (obviously), check as
well that the system does indeed fail when you would expect it to fail (much
- Don't stop when the problem disappears, but carry on to the end of the
list. There could always be more than one cause...
- If you need to narrow the cause down further, use the same approach.
Having identified the faulty item, break it down into its sub-components,
and swap each sub-component out in turn.
Final comment is to always build your boat so your components are readily
removable, replaceable, and exchangeable. In RC yachting, that means a number of
- Make the aerial disconnectable, with a plug and socket about 2" from
the Rx. This means you can swap the Rx out for testing very easily.
- Use a battery pack with a "standard" connector so you can try
your buddy's if necessary. You really don't want to be the only guy at the
pond with the latest special and completely unique "Futolex"
- Don't "hard-wire" anything in; no glue, no soldering, no having
to remove or break out panels or bulkheads first.
- Have a second item of everything to hand, even if it you'd probably never
actually use it, just so long as it works. I've got a complete second RC
system (Tx, Rx, rudder servo, winch, battery packs) that is all second-hand,
very cruddy stuff, but it works. Saved me at the European champs when I
could only isolate a glitch by seeing how it happened on the second system,
out of the boat.
Ken Binks has commented that it might be worth emphasising that aerial length
on the Rx should stay the same OR be doubled if you are going to make it
detachable, and that carbon hulls need their aerial to see daylight (not be
buried in the hull or pot)!