Can someone please explain the difference in the term Dual Conversion receiver as opposed to a single conversion one? I have a Futaba 9chp transmitter is it ok to use a single conversion transmitter. Also while your at it, explain positive & negative shift, and how it relates to my transmitter. Thank you,,,

Basically, the term "dual conversion" means your receiver is looking at the signal twice as much as a "single conversion" The higher end JR's are also DC. If you have a 9C, either new or old, they are designed for dual conversion FM and PCM. All of the new Futaba FM receivers are DC. I have used a 9C for a couple of years and just had to send it in for overhaul. I bought a new 9C super, and love it too. I would highly recommend you stick to Futaba receivers. If you really have to buy something less expensive, then stick with the clones from Tower and Hobbico. They are really 7 channel futabas dual conversion, with a different name on them. You can't beat the price of the eight channel PCM futaba, and the reliability and dependability can't be beat for the money. I must confess, I have one FMA Direct, lightweight, dual conversion 8 channel, that I use in a cheaper 3D airplane, and have had good luck with it so far. It wasn't really all the cheap at $69.95, when you consider I could have bought a PCM for $30.00 more. Good luck with your 9C, just remember, your airplane needs a good receiver to be safe.

Thanks for the info mike,, I was just going to add a small electric park flyer to my collection and was just wondering if I could even use a single conversion rcvr since they are so much cheaper, and this plane is so small it won't get too far away any,,or at least shouldn't. I wasn't sure if my transmitter could use a single as well as a dual. Thanks,

Ron

Read this from the Berg site. Good explanation of Dual conversion versus Single conversion and also some other helpful info.

http://www.bergent.net/SC-DC.pdf

Duke

Berg Is single conversion, but with all the filtering and whatnot that Peter has done to it, it is as good as any dual conv. reciever. Has some other innovations such as, on electrics, if it loses signal, servos stay where they are and goes to low throttle like a PCM. I don't work for Berg, I just use them.

Ron your Tx certainly can operate a single conversion Rx. The filtering senario used by the Rx has nothing to do with the Tx. Also you do not have to stick with Futaba Rx's, in some cases the cheaper after market Rx's are superior performers as a matter of fact.

Don,t confuse the Rx conversion methods with modulation shift. This is an entirely differant matter and not being an electronic egg head I am not going to try and explain. What is important for you to understand is that the Rx and Tx must be of the same shift, either positive or negative. Most aftermarket Rx's can be ordered in the shift required and some are switchable. Also sonme Tx's are selectable for either shift but this is a valuble function that you will never see on any Futaba Tx, All Futaba Tx sold in north america are Negative shift.

Mickeyboyd, wrong, wrong wrong. Dual conversion is when the reciever uses two IF frequencies, typically 10.7 MHZ for the first conversion and then 455 KHZ for the second conversion. Basically, the reciever crystal (on a dual conversion receiver) is either 10.7 MHZ above or below the transmitted frequency. The IF (intermediate frequency) is then amplified and then mixed with another crystal to give a second IF of 455 MHZ. This is then amplified and decoded and sent to the servos. A single conversion reciever skips the 10.7 MHZ portion--converts to an IF or 455 KHZ immediately. Both systems work as well as far as sensitivity goes, dual conversion is usually better able to handle some forms of interferance, especially second order harmonic distortion.

Go read the Berg link I posted, this is all covered in there.

Duke