Adding tones to Raptor

[h9361]

Sorry, I don't know.

Hello
Dear Carl
i hope you are in good health.
Yesterday, i finished Raptor project and it works very nice.
The question that is here, is it possible to add two tones in it?
Suppose, we set disc switch over 3. So, Raptor produces ferrous tone for 1,2 and 3 and produce non-ferrous tone for 4 and 5.
Do you think it's possible?
Thanks

[Carl-NC]

I moved your question to a new thread since it has nothing to do with the Hammerhead project.

The Raptor discriminates by changing the demod phase. I think the best you can do is give a low tone for discriminated targets and a high tone for accepted targets, no matter the switch setting. It probably involves adding more comparators.

Edit: You will also need a second tone generator (555 timer).

[h9361]

I moved your question to a new thread since it has nothing to do with the Hammerhead project.

The Raptor discriminates by changing the demod phase. I think the best you can do is give a low tone for discriminated targets and a high tone for accepted targets, no matter the switch setting. It probably involves adding more comparators.

Edit: You will also need a second tone generator (555 timer).

Thanks for creating a new thread.
Is it possible to guide me for adding two tones?
I draw a extra comparator and 555, but don't know how use it.

[Carl-NC]

It would take me a lot of time to figure this out, and I just don't have the time. Maybe someone else has looked at this.

[h9361]

It would take me a lot of time to figure this out, and I just don't have the time. Maybe someone else has looked at this.

Thank you.
I will wait until you have enough time.

[Carl-NC]

That will be when I retire, maybe in 10 years. Figure out what conditions trip the comparators, and then you can figure out how a discriminated signal can trip a different comparator.

[h9361]

That will be when I retire, maybe in 10 years. Figure out what conditions trip the comparators, and then you can figure out how a discriminated signal can trip a different comparator.

Thank you.
Is it possible to guide me in the overall schematic?

[h9361]

That will be when I retire, maybe in 10 years. Figure out what conditions trip the comparators, and then you can figure out how a discriminated signal can trip a different comparator.

I tried to figure out a correct schematic.
I hope it's correct. Is it true?

[Carl-NC]

No, not even close. The audio oscillator is gated by D1. You need a second oscillator that is separately gated but feeds into the same audio driver. This will take some figuring out. If you have a working circuit, then use an oscope to learn how it works.

[h9361]

No, not even close. The audio oscillator is gated by D1. You need a second oscillator that is separately gated but feeds into the same audio driver. This will take some figuring out. If you have a working circuit, then use an oscope to learn how it works.

Thank you.
Dear Carl
I tried to find 64OHM mylar speaker, but i couldn't.
So, i tested it with 22, 32 and 150 OHM. Unfortunately, its volume still is vey low.
Do you have any suggestion for increasing?
Is it possible to change it so that be able to use 8OHM speaker? because 8ohm is abundant.
Thanks.

[pechkata]

LM386...

[h9361]

No, not even close. The audio oscillator is gated by D1. You need a second oscillator that is separately gated but feeds into the same audio driver. This will take some figuring out. If you have a working circuit, then use an oscope to learn how it works.

hello dear Carl
I tested Raptor project, i think its sensitivity is low.
Do you have any suggestion for changing (play with some components ) for increasing its sensitivity?
I want to do increase is sensitivity.
Thanks.

[Carl-NC]

There are a lot of places in the circuit where you can increase gains but you are more likely to create instability than get better sensitivity. The Raptor is very close to common Tesoro designs so it should work pretty well. Why do you think the sensitivity is low? What targets are getting what depth? Is the disc turned all the way to minimum?

[h9361]

There are a lot of places in the circuit where you can increase gains but you are more likely to create instability than get better sensitivity. The Raptor is very close to common Tesoro designs so it should work pretty well. Why do you think the sensitivity is low? What targets are getting what depth? Is the disc turned all the way to minimum?

I also built TGSL project, it also has a low sensitivity.
I remember that i tested the relic striker metal detector, its sensitivity is very very high! I think the Relic schematic is like Raptor or TGSL ( analogue mode).
I tested a coin from 41cm using its 18x15 coil. In addition, i tested it with a Steel tray (45cm diameter), it detects from 195-200cm distance!
None of Raptor and TGSL can reach such depth!
I attached TGSL schematic, is it possible to suggest me some point for palying it?
In TGSL schematic, i increased both 470K to 1.5M. My sensitivity increased but not such Relic. I also tested it with two 2.2M, but its stability was very very bad.

[Carl-NC]

You've already found that increasing a gain can cause stability problems. To compensate for that, you might also have to reduce the bandwidth.

I have no idea how the Relic Striker is getting better depth. Maybe they are running a much higher TX current, you could try that by reducing R1. The big coil also helps, use a 40+ cm coil on the TGSL. Finally, the relic striker runs at 4.8kHz and using a lower frequency will help with high conductors.

Getting more depth out of a circuit isn't easy. If it was, the person who designed it would have already done it.