ORIGINAL: ChuckN
The 92985 is the older 512PCM Rx. It should work with your RD800 if you use the PCM1 setting. If not try PCM2. One or the other should work. Use regular Airtronics dual conversion crystals in their PCM Rx's. Don't be tempted to use another brand as different manufacturers tune their crystals differently.
You sure ?
Brian for airtronics told me it will not work with my rd8000.
I guess I just need to try (and hope).