Hello everyone,
Till date i have been using Futaba dual conversion Rxs with crystals. However now i see many brands of Rxs that are "synthesized" , and can work in a range of frequencies. How do they compare against each other. Apart from the obvious advantage of not being tied to a single frequency, is there any disadvantage/range problems ?
Then, how do the Corona synthesized Txs compare to the ones from Futaba.
Let me know your views here.
-Gaurav
PS: I intend to use these low cost corona synthesized Rxs in my older planes, gliders etc..

I use the corona synth receivers extensively  and have had no issues what so ever . the range is huge 1 mile . We have a standing joke around here that you could  do a range check from home.

The biggest advantage from my point of view is they are auto shift hence I can use the same receiver with my Futaba as well as JR transmitters .

Don't know how they work with Hitec.

Sai

Before 2.4 became the name of the game, the beefiest of Futaba radios (like the "show off" 14MZ) came with such synthesized receivers as the standard package.  Tons of scale and IMAC flyers use them, so I don't think there is a lot of bad history out there.

I hope you don't have to change the channel every other day, since any such mechanical movement would have some kind of life span (of N number of changes, whatever that N be).

Is that possible to use Corona Synthesized RX (35 Mhz) link :

http://www.hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=5785&Product_Name=Corona_Synthesized_Receiver_4Ch_35Mhz___%28v2%29

with my Esky 4Ch 35Mhz TX?

WE HAVE 35 MHZ AVAILABLE :
http://cgi.ebay.in/ws/eBayISAPI.dll?ViewItem&item=150419243297

FRANKLY  FOR A DIFF OF USD $ 4  I WOULD RATHER GO IN FOR A 8CH RATHER THAN A 4 CH

SAI

I have futaba skysport 4ch 72MHz with dual conversion crystal. Can I use Corona 72Mhz synthesized rx with this transmitter..? Or is there any type of modification needed to make it compatible..?

I fly with a Futaba 9 CAPS, (S stands for synthesized) and similar sysnthesized Rx. No issues with the equipment at all. As pointed by Anwar, the Frequency is set when the set was purchased and have never fiddled with that. So nothing to go wrong due to frequent mechanical movement

Captain - I am pretty sure that "S" stands for "Super", which is like a beefed up version of the original 9C (9CAP/9CHP).

And by default the 9CAPS will not be synthesized, it will come with a fixed channel module.  You have to get the TP-FSM module with the dials to make it synthesized (http://www.rcuniverse.com/magazine/article_display.cfm?article_id=542).  You can use the same module to make other radios also "synthesized", including the original 9C and 10C (not the 10CG though).

Spitfire - Transmitters have no concept of single or dual conversion, from what I know.  It it only at the receiver side.  So you should be able to use both single and dual conversion synthesized Corona receivers with your TX.

Is it needed to change existing crystal with corona crystal or the existing one will work fine...?

First of all, synthesized receivers do not have crystals.  If they had, they would need 60 of them  

Secondly, changing the channel of a TX is a bad idea, as it calls for recalibration. Best case you can go one or two channels up or down. 

In short, your TX stays the same, and it will transmit in whatever channel it has always been using.  When you "bind" the corona synthesized receiver to this TX, it will scan, find and lock on to the same channel as the TX.  Once bound, the RX will "remember" this, and will be ready for use again and again without the need to rebind (unless you need to bind it to another TX on a different channel).

Does this mean it is better to use 4ch or 6ch synthesized receiver for 4ch tx than 9ch receiver ...?   

If your transmitter has 4 channels only, then the receiver can only act upon those, regardless of the number of channels on the RX itself.  That said, you can consider getting an RX with more channels, as they can be used with a TX that has more channels later on.  Of course, the price difference should justify such an investment.

I was looking forward buying one of following
9ch http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6406
6ch http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7527

Should I buy 9ch one or 6ch one as 9ch is cheaper than 6ch..?

Can't see anything in the description which makes one better than the other (other than more channels, which you may or may not find useful). 

I only have the 6 channel one, so can't really comment on the other one in terms of personal experience. 

Why does the 9 channel cost less than the 6 channel, I wonder though !  The filtering stages used on the 6channel are better highlighted in the description of the 6 channel one, while it is just the word "DSP" on the other one.  Not sure if that means whether the 6ch one has better filtering circuitry