1. Home
  2. Electronic Components
  3. Receiver & Transmitter module

Receiver & Transmitter module

Hi All,

There are 2 "SAW resonator" (I presume); 1 in the receiver module and another in the transmitter - DIP, metal casing; similar to an oscillator.

I went through the web trying to understand about this component, however there are none stating a "receiving resonator" or "transmitting resonator".

The query is raised as i saw the markings on these components "R447.9375" on the receiver module and "T447.975" on the transmitting module.

My assumption:

  1. "R" & "T" denotes receive & transmit respectively.
  2. The digits represent the frequencies.
  3. If I replace these 2 "R" and "T" to same frequency value, they should work.

Not sure if these assumptions are true or these components are not resonators. Can anyone help please?

Btw the exact markings on the receiver is: R447.9375

87.4475 SE-0401

Thanks in advance. ywz

Reply to
ydoubleuz
Loading thread data ...

They should work if the frequency is close enough so the signal can pass any tuned circuit or filter in its path, should they exist.

They should be SAW based as, IIRC, crystals cannot go that high in frequency by themselves. Many resonators I've encountered are "crystal- like" passive devices, ie. something that can be put in oscillation into an active circuit or used as a filter depending on how you connect it, but information is a bit scarce on the net. Some examples can be found though by googling for saw+schematic+receiver(or transmitter).

If anybody has more information, I'm interested in the subject as well!

Reply to
asdf

Don't seems to be much interests online...

The confusing part is the marking "R" & "T" ... if they are resonators then they should not be differentiated between transmitter and receiver.

Googling on "saw resonator" did not provide any insights the the difference between the receiver and transmitted.

Am I missing something here?

Lets hope some gurus will provide some leads. =)

Reply to
ydoubleuz

It would depend on what they are being used for.

For signal frequency filtering, there wouldn't be a different.

But SAWs are also used in oscillators, and a lot of recievers are superheterodyne where the incoming signal is mixed a different frequency. In that case, the transmit SAW would be at 500MHz (just as an example) while the receiver SAW would be at 490MHz (so the signal is mixed down to

10MHz).

I don't know what the norm is for SAWs, but in the old days it was common to stamp crystals with the signal frequency, rather than the fundamental frequency it really oscillated on, or the frequency it injected into the receiver to convert the signal frequency down to the intermediate frequency. Sometimes they might be marked with "T" or "R" to indicate their function, but you couldn't tell their actual frequency without putting it in an oscillator to measure, or without knowing the equipment it was intended for (which would then define where the transmit oscillator oscillated at and how much that was multiplied, and then the IF frequency of the receiver and again how many times the receive oscillator wsa multiplied).

Michael

Reply to
Michael Black

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.