Reading Wireless Air Transmitter using Arduino

[Robbyg]

How do you conclude this? From https://www.researchgate.net/profil...mmunication.pdf?origin=figuresDialog_download, we find this figure:
View attachment 641529

The attenuation at 38kHz is less than10 dB/m, and the signal goes 2m at most.

Don't know where they got that info from but it is a study on" Optical Transmitters" and not Radio Transmitters. I found my info in a study that tested loop antennas 100ft apart underwater in sea water and they found that 10W of RF power at 30Khz was needed to keep the signal clean at 100ft. I suspect they used much better receivers than what is found in a DC,

Keep doing your own research and come back when you have answers that actually solve the problem. I am more than willing to work with anybody who has real solutions to the problem.

 

[Robbyg]

Question.
If you're trying to produce a receiver, why not just reverse engineer a functional receiver?
A donor computer would provide you the next step, no?

Probably if it was something like a Perdix AI it could work but the watch style units are going to be so compact that it's going to be a nightmare probing around in there. I don't think most people realize how small the components can get in these compact devices. I have to use a 50x microscope to work on these things.

 

[Coztick]

Probably if it was something like a Perdix AI it could work but the watch style units are going to be so compact that it's going to be a nightmare probing around in there. I don't think most people realize how small the components can get in these compact devices. I have to use a 50x microscope to work on these things.

I could see that...
I was assuming one could disassemble/dissect a donner unit.
Thanks for the reply!

 

[tursiops]

Don't know where they got that info from but it is a study on" Optical Transmitters" and not Radio Transmitters.

I guess you did not read the study. The figure was in the report I linked to, and was taken from a book, Ref 41 in the report:
[41] M. Lanzagorta, Underwater Communications. San Rafael, CA, USA: Morgan & Claypool, 2013. https://doi.org/10.2200/S00409ED1V01Y201203COM006
I do not have access to that through my library; perhaps you do.
How do YOU scale 10W at 100 ft down to 2m?

 

[Robbyg]

http://www.jpier.org/PIERM/pierm41/19.15012106.pdf

 

[tursiops]

http://www.jpier.org/PIERM/pierm41/19.15012106.pdf

Are you using Eqn 14 in that paper to estimate how much power is needed at 1m vers 33m? in your 10W at 33m example?
If so, it seems the answer would be more like 0.3W than the 3-5W you mentioned.

 

[Robbyg]

Are you using Eqn 14 in that paper to estimate how much power is needed at 1m vers 33m? in your 10W at 33m example?
If so, it seems the answer would be more like 0.3W than the 3-5W you mentioned.

I said .5w to 1w
It's also going to be very dependent on having a resonant antenna which is impossible at the this Frequency. Also the DC receiver is also likely to be rubbish.

 

[tursiops]

I said .5w to 1w
It's also going to be very dependent on having a resonant antenna which is impossible at the this Frequency. Also the DC receiver is also likely to be rubbish.

Agreed, no resonant antennas on either end. But also no need for a "clean signal" either....just good enough. Sorry for the confusion on how much power you thought might be required. What was the citation for that project that used 10W?

 

[Robbyg]

Don’t know I cannot find the article again. I had read about it a few weeks before I made the first post.

 

[telemonster]

I tried to RX the transmissions while troubleshooting my Perdix AI xmitter. I was using an ICOM pro 756 II HAM radio and I saw nothing, even with the end of the coax up against the transmitter. It has a spectrum analyzer type function... nothing. The 38KHz frequency is at the very bottom of what it can receive.

The FCC database might have a report on the transmitter for testing. ELMO I think the database is called if I remember right.