I tried to build a radio receiver

[David lopez]

i have ts832 transmitter and a rs832 receiver. i tried to build a radio receiver to pick up radio signals from the ts832 transmitter,. i measured the ts832's antenna. it was 8.8 centimeters. so i cut a piece of copper wire 8.8 centimeters long. i connected the bottom of the copper wire to two other wires. 1 wire was connected to the black prong of a multimeter. the other wire was connected to the red prong of the multimeter. i set the multimeter to 200 milliamps. i don't think i got a signal. most of the time the multimeter read zero. sometimes the multimeter, read 0.1 or 0.2 or 4. it uses the 5.8 cm band. how do i build an antenna that can pick up a radio signal from this ts832?

 

[Joshy]

My first guess would be there's a mismatch between your wire that you're using as an antenna and the board or connector. I would be surprised if they didn't choose a thickness/width, shape to those antennas beyond its length to achieve a certain characteristic impedance (often 50 Ohms). Quick note just in case readers might not be familiar, that resistance, impedance, and characteristic impedance are not the same. Would you be able to try another wire that has a different diameter compared to your first one?

I've heard stories of people mucking around with coat hangers until they can get it to pick up a signal. I'm not sure you'll be so lucky if the TS832 really is 5.8 GHz (I'm looking at https://www.amazon.com/dp/B00MLS0NOW/?tag=pfamazon01-20). You could try. I'm no expert with antennas, but I thought the length should be like 12.9 cm if it's just copper in air... I chose that number because it's λ/4...

 

[David lopez]

so you think i should use 12.9 cm and a different diameter? should i use a thicker diameter or a thinner diameter?

 

[BvU]

i have ts832 transmitter and a rs832 receiver

You mean RC832 ? With an antenna ? Why not use that ?

 

[Joshy]

Let's try it in steps and just do the length first. You might be able to get something from it.

This isn't my area of expertise (antennas that is), but I would try approximately a twin wire transmission line and impedance match roughly using that. I'd use an online calculator like this with a dielectric constant of 1 (vacuum or air), and a permeability constant of 1 (as long as it's not nickel, iron...). Measure the spacing between the terminals for input 3 and choose a few different diameters until you can get about 50 Ohms.

https://www.rfwireless-world.com/calculators/Twin-wire-line-calculator.html

 

[David lopez]

so make sure the antenna has 50 ohms?

 

[Joshy]

That's what I would try.

 

[David lopez]

so make sure the resistance of the copper wire is 50 ohm?

 

[berkeman]

@David lopez you have not answered the question by @BvU

You mean RC832 ? With an antenna ? Why not use that ?

If you have a complete receiver for this link testing, why are you trying to make your own antenna?

so make sure the antenna has 50 ohms?

If you have one of these:

https://i.ebayimg.com/images/g/k08AAOSwrdlcaD3b/s-l300.jpg

 

[David lopez]

You mean RC832 ? With an antenna ? Why not use that ?

because i am trying to get more range. an antenna picks up the radio signals from ts832 transmitter and sends the signal to a second antenna that will retransmit the signal at higher frequency to get longer range.

 

[David lopez]

you still have not answered my question, so i make sure the piece of copper wire has a resistance of 50 ohms?

 

[berkeman]

you still have not answered my question, so i make sure the piece of copper wire has a resistance of 50 ohms?

Of course not, since your question is nonsense, yet again. You are trying to learn, and that is a good thing. But you are stumbling around in areas where you can cause harmful communication interference to others, and that is not good.

And even though you are finally trying to use canned transmitters and receivers for your projects, you are asking us for help violating the law by replacing the standard monopole antennas with high gain Yagi antennas, which will likely violate the Tx power testing that was done on those licensed transmitters.

As much as I admire your desire to learn and do EE projects, it is time you had a brief vacation from the PF. We do not tolerate repeated efforts to violate the law.