I can confirm that the GB units that were last shipped did in fact work with JR/Spectrum. There was a small change made to the comparator circuit a few years ago, but that's the only thing I can think of that would potentially have an effect. I use to service and program these for PST Jets, as their ECU use to be a re-labelled GB hobby unit with slightly modified programming. Its also my understanding that Gordon and Bruce have shut down the operation.

If you need help or have questions, PM me and I'll do my best to help you out.

Kelly

PS: not that anyone asked but always range check an aircraft with a GB ECU with the data terminal disconnected. On my Futaba gear, it significantly reduced the range.