FS1000A Transmitter-Receiver ?

[DELTA67]

Hi all,
I've bouhgt an FS1000A RF transmitter and receiver pair.
1- On most photos on the  web:
- The transmitter has 2 coils, mine has only the big one! Is this normal??
- The receiver reference is XY-MK-5V,  mine is MX-RM-5V. What's the difference between them?

2- I powered the 2 modules with 5V and test the DATA pin of the receiver with a voltmeter, in DC position while the  data pin of the trasmitter connected to Vcc (5V) and when it's floating or connected to GND. The result: No difference (about 0V)!!!
I suppose that I must add the missing coil on the transmitter, No?

3- What are the expected results?
   - In the case when the data pin of the trasmitter is connected to Vcc (5V).
   - In the case when it's floating or connected to GND.

4- The SAW resonator has R315 as marking, but no thing indicating the working frequency of the receiver.
   Is there any simple way to know if the modules are paired or not? 

Thanks

[DELTA67]

Well, I'll answer my self!
1- Some FS1000A transmitter models have replaced the smaller coil with an smd inductor.
    but we can add our own coil:
    https://vk4ghz.com/fs1000a-433-mhz-transmitter-l2-missing
2- The transmitter must be powered with 6-12V and must be very close (some cm) to the receiver in order to get some thing.