Model Forum / Radio Controlled / Air Models / June 2004

You MUST use dual conversion crystals. There is nothing special about them.
The single conversion crystals on ebay are for use on old equipment or
foreign use. DO  NOT BUY THEM unless you have a single conversion receiver.
Regular dual conversion crystals are available from tower hobbies, servo
city, or any of a number of different places.

The FF7 is a transmitter, not a receiver.  Single conversion and dual
conversion are receiver terms, not transmitter terms, so those
crystals are definately very wrong.

Transmitter and receiver crystals are typically different, and single
conversion and dual conversion receiver crystals are different as well
(from each other.)  To make matters worse, crystals from different
manufacturers are often different as well.

To be safe, get crystals from Futaba -- don't try to save money
getting them on Ebay until you know what you're doing.

Of course, some people don't like you changing crystals at all on your
own.  But as long as you get the right crystals, and don't stray more
than a few channels from your original frequency, you're probably
fine.