1
\$\begingroup\$

Currently I have a setup where a 433MHz Transmitter sends a number from one arduino and a 433MHz receiver picks it up for another arduino. The Transmitter and receiver are of the Super Regenerative type if I'm correct (picture below).

enter image description here

My question is can another type of 433MHz Receiver pick up the same signal? A Super Heterodyne Type?

\$\endgroup\$
  • 1
    \$\begingroup\$ Yes, it's just like any other radio system. The transmitter broadcasts a signal, all receivers in range pick up the signal. Same as when you yell. Everyone around you can hear. Maybe your question is 'is the transmission coded so only the intended recipient can decode it'. The answer to that would be, it is totally up to you. You would do the encoding/decoding in your Arduino. These RX/TX modules are super simple: if you TX 101110, the receiver outputs 101110 (and then noise after some time). \$\endgroup\$ – Vince Patron Jan 31 '18 at 1:55
  • \$\begingroup\$ Thank you, no my transmission is not encoded/encrypted, it's just broadcasting a simple reading from an ultrasonic distance measuring module. \$\endgroup\$ – Kokachi Jan 31 '18 at 3:46
3
\$\begingroup\$

The Transmitter and receiver are of the Super Regenerative type if I'm correct

Nope, they're not.

Super Regenerative means it is an oscillating receiver circuit.

That transmitter is just a 433 MHz oscillator. Super Regenerative Transmitters do not exist.

That receiver could be Super Regenerative type, the only thing I know for sure that these receiver models aren't very sensitive. I know, I own one and its not that good.

Much better is a Super heterodyne receiver module, they have a chip and usually look something like this:

enter image description here

There's also a smaller version which looks like:

enter image description here

Some of these use the SYN470R chip.

Note how there are far less passive components. This type of receiver is much better than the one from your picture. It is also only slightly more expensive and well worth that few extra cents.

\$\endgroup\$
  • \$\begingroup\$ I meant the receiver, I should have been more clear. The Receiver I showed also has a 8 pin chip on it, it's missing a crystal though. I have seen the model you shown above, but they're all being advertised as ASK type, mine would be of OOK type if I'm correct. \$\endgroup\$ – Kokachi Jan 31 '18 at 3:52
  • 1
    \$\begingroup\$ Yes but that 8-pin chip are opamps, not an RF receiver like on the module I suggest. The Crystal is needed for a superhet. to make right mixing frequencies needed. ASK with 100% modulation depth is the same as OOK. That simple transmitter from your picture cannot do anything else but ASK with a 100% mod. depth, and basically that's the same as OOK. So don't worry about ASK vs OOK. \$\endgroup\$ – Bimpelrekkie Jan 31 '18 at 6:33
  • \$\begingroup\$ I see. I found another module advertised as Superheterodyne but looks like it has only an 8 pin chip. Fake advertising maybe? \$\endgroup\$ – Kokachi Jan 31 '18 at 16:56
  • 1
    \$\begingroup\$ @Kokachi Note how that module also has a crystal! I am quite sure it is a more modern version of the Superheterodyne receiver modules. I also have a similar one using a SYN470R chip. So not fake and it is a Superheterodyne receiver. The ones that I have work quite well, they have good sensitivity. The matching transmit module uses a SYN113 or SYN115 chip but you don't need these per sé, the SYN470R receiver works fine with the transmit module from your picture. \$\endgroup\$ – Bimpelrekkie Jan 31 '18 at 18:24
  • \$\begingroup\$ Thanks for the very informative reply. I've always wondered what was that component they used instead of a crystal in my receiver. Is it a trimmer capacitor? \$\endgroup\$ – Kokachi Feb 1 '18 at 3:17
3
\$\begingroup\$

Short answer: Yes a superheterodyne receiver can "pick up" the transmitted signal.

Be aware that the transmitter side is a transmitter+modem: The transmitter accepts a digital input signal to be sent . And the super-regenerative receiver shown is a receiver+ modem: it outputs a digital signal.
A superheterodyne receiver very likely has no modem...it outputs an analog signal which would require an additional modem-type circuit to re-generate the digital signal.

The modules shown use a very simple modem scheme. It is often called on-off-keying (OOK). It is very similar to Morse code.

\$\endgroup\$
  • 1
    \$\begingroup\$ Moderns modulate and demodulate. And any evidence that the other type does not demodulate the signal? \$\endgroup\$ – Passerby Jan 30 '18 at 22:18
  • 1
    \$\begingroup\$ @Passerby Both superheterodyne and super-regenerative radio receivers have traditionally not included digital demodulators. That idea is at risk of the more modern concept of radio as a link in a chain of digital signals. A great many radio chips now include modems. \$\endgroup\$ – glen_geek Jan 31 '18 at 2:27
  • \$\begingroup\$ Thanks. What if the receiver is of ASK type and not OOK type, would it still pick up the broadcast? \$\endgroup\$ – Kokachi Jan 31 '18 at 3:58
  • 2
    \$\begingroup\$ @Kokachi ASK modulation with a 100% modulation depth is identical to OOK modulation. So Yes, the data can be received provided that the transmitter does ASK with 100% mod. depth (then basically it is doing OOK). \$\endgroup\$ – Bimpelrekkie Jan 31 '18 at 6:30

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.