Receiver Specifications
 and Comparisons

My first receivers used receiver modules from Radio Shack and from Quality Kits.  They were similar to the one immediately below sold by CommLinx.

RLP315

  315MHz ASK Receiver - L/C based 

  • 5 Volt operation
  • digital and linear outputs
  • Sensitivity: 3uV/-100dBm RMS
  • Data rate of 3Kb/s

 more detailed specifications (pdf format)

Since then, I found specifications on a more sensitive receiver shown below and ordered one for testing with the new circuit board.

RLP315A

 315MHz ASK Receiver with SAW Resonator

  • 3.3 - 6 Volt Operation @ 4.5mA
  • Channel Width: +-500KHz
  • Turn-On Time: 5ms
  • Data Rate: 4.8KBs Basboard
  • Sensitivity: 110dBm
  • Noise Equivilant BW: 4KHz

 more detailed specifications (pdf format)

 

These appear to be the modules from the manufacturer Wenshing in Taiwan.  The modules and specs below from Wenshing are 433.92 mhz but different model numbers are available for each of the 3 frequencies mentioned in the construction article.  Remember you must choose the same frequency for the transmitter as you choose for the receiver and the yagi antenna. 

 
433.92MHz
5V
-106dB
4800bps
4.8mA!S0.5mA Modulate Mode:ASK;Circuit Shape:LC;
Sensitivity:-106dB;Channel Spacing:1MHz

 

433.92MHz
3.5~6V
-116dB
4800bps
7.5mA!S0.5mA(DC/5V) Frequency Range: 433.92 MHz;Modulate Mode: ASK;
Circuit Shape: S/R+S/F;Data Rate: 4800 bps;Sensitivity: -116 dB;

 

 
433.92MHz
4.5~5.5V
-116dB
4800bps
7.5mA!S0.5mA(DC/5V) Frequency Range: 433.92MHz;Modulate Mode: ASK;
Circuit Shape: S/R+S/F;Data Rate: 4800 bps;Sensitivity: -116 dB
 

 

The NEW receiver module which I actually received for testing turned out to be the RWS-436-4.  It uses more current than the oldest model.  This RWS-436-4 module did NOT work until I ungrounded pin 6 (designated E/D).  I do not know if it will be necessary to float pin 6 on the other SAW based receivers such as the RLP-315A or the RWS-434-4.

The audio output of my completed project using the new RWS-436-4 module was a good bit lower than my old design.  I also found that it was necessary to use data output rather than the analog output.  So, I wound up unsoldering the “ear output” pin (pin 3) from the receiver module and bent the digital output pin (pin 2) so that it would insert into hole 3 on my board.  Experimenting with a higher current voltage regulator made no difference.  I do not know the reason for the difference in audio levels and pin-outs in the RWS-436-4 receiver module.  But the lower audio from them is still quite useable and extremely loud on headphones.

As expected, testing showed that the RWS-436-4 module is sensitive to low level signals.

Given the fact that the new modules are only a few dollars higher than the old modules, I'll definitely be staying with the new ones.  Both were obtained from Quality Kits.  (Don't be misled by the diagram showing the older 6 pin transmitters.  They are selling the new smaller and better 4 pin transmitters - which happen to fit my board.)