Synthesized Receivers

I understand how 2.4 gh systems "bind" the transmitter to the receiver, but
synthesized receivers are new to me. Is there a similar "binding" process?
In other words, how does a synthesized receiver function when several
transmitters are operating in the area? Can I use a synthesized receiver
with a non-synthesized transmitter? How about using an Airtronics
synthesized receiver with a Futaba non-synthesized transmitter?
TIA, Randy
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essentially if you mean synthesized HF receivers, they simply tune into the strongest signal when switched on. And stay there.
Apart from that they are just like a normal crystal receiver. Except the oscillator may not be as 'pure' as a crystal, meaning they may be more prone to interference.
Reply to
The Natural Philosopher
Most (all?) the synthesized RXs have some kind of procedure to set the frequency and lock it in. Some have set switches, others have modules you connect when changing the freq and then disconnect. They stay "set" to the chosen frequency until programmed differently. They don't hunt for frequencies the same way 2.4Ghz systems do.
I know Polk Seeker RXs will work with any 72Mhz TX. Several third party RXs will work with anything. I don't know, but suspect JR synth RXs will still only work with positive shift TXs and Futaba synth RXs will only work with negative shift TXs....
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Um... I can't say for all receivers, but what's for sure is that any kind of "binding" is not in any way essential for the operation of synthesized receivers.
Synthesized receiver is basically the same thing as an ordinary receiver, except that in the ordinary receiver you have a crystal, which assigns that receiver to a specific fixed channel. In a synthesized receiver instead of a crystal, you have a bunch of dials that let you set a specific fixed channel (or a bunch of buttons). In order to switch the channel in the ordinary receiver, you need to replace the crystal. In order to switch the channel in the synthesized receiver, you need to turn a dial or two. That's it.
As for the "several transmitters" issue, these receivers are the same. If another transmitter comes up on the same channel, the model gets shot down, regardless of whether your receiver is synthesized or not.
There are synthesized receivers that can automatically adjust their channel. Instead of turning dials, you have to bring your transmitter close to the receiver, and the receiver will "learn and remember" its channel. From the outside if might look like some kind of "binding" (and it might be referred to as such), but in reality this is just another way to set the channel in some synthesized receivers, instead of turning dials. This is a mere convenience feature (you don't have to pull the receiver out of the model to turn the dials), and once the channel is set, the rest from that moment on works just like a good old receiver with a crystal.
Finally, there are 72MHz FM receivers out there with "advanced features" that involve the actual "binding" of the receiver to the transmitter of some sort, i.e. the receiver somehow knows how the recognize its own transmitter and ignore all others. However, firstly, this has nothing to do with the receiver's being "synthesized" - the same thing can be implemented in a receiver with a crystal. And secondly, once again, this feature has rather limited effect in 72MHz systems, because once another transmitter working on the same channel starts to overwhelm the proper transmitter, there no way to ignore it anymore and the contact gets lost.
Of course, as long as they are compatible in all other regards.
Well, if Airtronics receivers in general are compatible with Futaba transmitters (or if, say, the Futaba transmitter can be set up to send the signal compatible with Airtronics receiver - like positive/negative shift and stuff), then yes, you can use them. This is, again, an issue of general compatibility between brands, completely unrelated to transmitter's/receiver's being synthesized or not.
Reply to
Andrey Tarasevich
"spread spectrum" and "synthesized" are two different things. Lately binding refers to Spread Spectrum 2.4 GHz radios. mk
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