Which Radio

[Alan_Perse]

Just a quick question. Synthetized means you can choose your frequency without using crystals right. Would a Multiplex synthetized Tx work with a hitec ( or other manufacturer) synthetized Rx. Or would you have to have a synthetized Rx from the same manufacturer as your TX.

[Fred]

Hi Alan, no need to be the same brand...
For instance, I'm using my JR with synthese corona receivers, and i do the same with my mpx evo9 with the corona synthese receivers...
No glitches what so ever !
 

[Ron]

Thanks for all the info chaps.

Alan: There seems to be a Cockpit MM now.
http://www.multiplexusa.com/product_fs.htm

But I'm still leaning towards the Evo 9.

Icewind: (Fernando - is that right?) Yes the 2.4 is out for me.
They used to say don't buy anything until it's at least up to version 2, and 2.4GHz is still at version 0.5 in many ways :lol:

And a synth TX module is a must.

As to the editing on a PC... If, and this is a big IF, I have absolutely nothing to do at all next winter, I might just look at writing something to do it.
After all, it says it saves a file of some sort to the PC, so it should be possible to read that file, modify it with a user friendly interface, and save it back again.
Hmmmm... Perhaps :wink:

[Ron]

Yep.
Synthesized is just the way the basic RF frequency is generated.
You either use a fixed device like a crystal, or you have an integrated circuit that also uses a crystal, but an internal one, and it generates whatever frequency you want according to switch positions or software settings.
The result is the same as far as the rest of the transmitter is concerned.
   

[Ron]

Just an add-on I thought of...

You don't even have to use a synth TX and synth RX together.
You could have a synth TX and a crystal RX, just as long as they are both on the same channel.

[Alan_Perse]

Thanks for the info Fred and Ron.
About the coctpit MM. I'm sure some shops may still have it but I think its out of production. The cockpit SX has replaced it.

[Alan_Perse]

Thanks for the info Fred and Ron.
About the coctpit MM. I'm sure some shops may still have it but I think its out of production. The cockpit SX has replaced it.

[Alan_Perse]

Opps double post  

[Ron]

Hi Alan,

Yes most shops seem to have the SX. It's only the Multiplex US web site that has the MM.

[IceWind]

Yes Ron it's Fernando. I may have to ask the admins here to change my nick! Everyone uses their name so should i.

Regarding the editing of the configs i think that is highly possible. If the file scheme was know it would be possible to edit it.

There is some work being done here: http://ourworld.compuserve.com/homepages/wallacelouie/cms.htm


Well regarding using only a synthesized part in one side, i don't see much use for that. Because the main advantage i'd take from it is to easily change channels. If i'm using cristals in one end i'd have to own the cristals for the different freq in the same way.
Unless and this is my question, are the synthesized modules and RX's modules more accurate? In what concerns filtering and not being so prone to parasite interference from nearby channels or other sources?

[Ron]

Hi Fernando,
Yes editing the config files is worth a look, if and when I get the urge

All I was thinking was, having a synth TX you could still use older crystal RXs that you might have laying around. That's if you haven't changed over completely yet.

As to stability and frequency accuracy, I would say the synth ones are better.
Crystals vary a lot from one to another.
What they tend to do in production is make a load of crystals and then pick out ones that are within limits for each channel. And sometimes the limits can be rather wide. After all, they have no reason to make the limits narrow as that just means they are throwing away more.
And sometimes the temperature characteristics of crystals is not good either.

As to filtering and interference rejection, naturally the better the frequency accuracy the better matched the TX and RX frequency are going to be, so there will be less tendency to pick up adjacent channels etc.
But generally, what determines the interference rejection is good, preferably double tuned RF stages, good I.F. (Intermediate Frequency) filtering with crystal filters, and double conversion helps a lot giving two opportunities for I.F. filtering, and other techie stuff to do with image response.

Hope that helps :lol:

I like the look of the Corona RXs. Good spec.

Ron

[Sean]

Hey Ron,
Leaving the boat in the shed for the season is one thing, but ditching your brown sails icon is too much Sailing boats are just gliders on water , with variable aerofoils, that sink instead of crashing.
Good luck with the flying, me at the same crack, have a mountain just crying out for a glider. War bird on the way.

Seán

[Ron]

HiYa Sean,

Wish it was in a shed. It's in a boatyard (costing an arm and a leg) with a big cover over it.
Sorry, her!
And there's jobs like pulling a keel bolt to check it's still in one piece after 48 years

Yes perhaps you're right.
The new one is supposed to be a Seaking over the - errr - sea.
But really it's just a shot from X-Plane simulator.

Original icon coming up.

What's the war bird?

Ron

[cvanscho]

The Cockpit SX is, I think, a considerably more powerful tranny than the older MM, and, given its very reasonable price for a Tx, I wouldnt recommend trying to sniff out an old MM.

Ron is right in that many of us have perfectly serviceable crystal recievers lying around, and you wouldn't want to ditch them.  Having a synth Tx just gives you more options, thats all.

I have used my synth SX with the following crystal Rx's with no problem(let's see now :?: ): Hitec electron 6, Jeti something-or -other, various 7 and 9 channel MPX ppm rx's, Schulze Alpha 8's, Futaba 6 and 4ch, Corona's.  The only synth Rx's I've used is the Simprop Scan 7, also works great.  I suspect Corona's are the best news we've had for a long time .

Fernando: you can go into your user profile and add in extra stuff such as your name (such as with my profile), without changing your username.  You could also just sign off with your name :roll: !

Chris

[Ron]

Yes I think it's got to be a Cockpit SX.
Good TX and a very reasonable price.
All I have to do now is find one  :?: