Single vs. Dual Conversion simply describes the type of signal filtering used in the receiver. Dual Conversion is generally considered better than single conversion, at least on paper. In actual use, however, high quality single conversion receivers from manufacturers like Berg (Castle) or JR perform as well as any dual conversion receiver.

One absolute gem of a receiver is the full range, dual conversion 8-channel shift selectable RD8SL receiver from GWS:

http://www.hobbycity.com/hobbycity/s...idProduct=4374

http://www.hobbycity.com/hobbycity/s...idCategory=195

The receiver is $24.99, and the 72Mhz GWS dual conversion crystal that goes with this receiver is $3.99. If you order 2 receivers and 2 crystals from Hobby City, they come in right at the maximum weight allowed for $5 shipping.

I'm flying one of these in my Sig King Kobra with my Futaba 7C, and I can't tell the difference between this GWS receiver compared to my Futaba or Hitec receivers. It is truly a high quality bargain.

Hobby City is in Hong Kong, so it will take about 3 weeks to get your order assuming the parts you want are in stock. This is one honey of a receiver for the price and well worth the wait.