Magnum on steroids!

[bandito]

Someone made this project to see how it works

[ivconic]

with the gm5 you can switch between 8 and 18 khz in the detector menu. I think it switches the "extra" wirerounds on that ivconic mentioned. You don´t have to change the coil and if I´m not wrong, than you can switch between the frequencies on the fly in your search process.

I think "extra" wirerounds has nothing to do with changing of frequency.
Those are there wired the same at all models starting from model 1+ to model 5 and serves to provide a portion of TX as reference for synchronous demodulator.
Speaking of model 5... i tested it detailed for some time.
It is decent try from manufacturer but i would have some remarks.
Software, the code, is somewhat slow in behavior.
There is annoying start up with complicated bitmap and it still haven't finishes; while at the same time you can hear detector behavior in background, for example.
Walking through menus and adjusting the parameters; i have direct impression that Atmega (one of those two) is used as bare "digital potentiometer" and nothing else.
Skim look on electronics shows the concept. It is obvious that it is still fully analogue design with addition of digital pot and LCD jingle&bells.
In essence it is still the model 4. A bit slower and sloppier in behavior. Audio is also kinda mum and inert, comparing to model 4.
Overall, despite the remarks, i am really impressed with the effort, knowing from earlier that it is small and independent manufacturer who started in similar fashion as many enthusiasts here on forum.
Fabrication quality is way over the hobbyists level, this is important to point on. Almost competitive to main league.
Still... if you ask me; model 4WD is my favorite and winer. Way over and far from closest competition and copies i mentioned earlier.

[mschmahl]

with the gm5 you can switch between 8 and 18 khz in the detector menu. I think it switches the "extra" wirerounds on that ivconic mentioned. You don´t have to change the coil and if I´m not wrong, than you can switch between the frequencies on the fly in your search process.

[SVEN1]

Thank you, just wanted to double triple check before I order a coil.

[ivconic]

Thank. may I ask for which model GM you bought the coil for? That will make it easier to find the right coil model version

As i said; the same coil works the same on all GM models from newer series, those in smaller enclosures.
From 1+UK to model 5.
And schematic and pcb i posted here is the same at all models from 1+UK to 4WD.

[SVEN1]

Thank. may I ask for which model GM you bought the coil for? That will make it easier to find the right coil model version

[ivconic]

Guess my coil thinking is flawed?
They offer the coils in either 8khz and 18khz.
So like Minelab Exterra if you want to use two frequencies you need to have two coils, then use the toggle switch on the control box to switch between them. https://thrace-detectors.com/product...olil-23cm.html
http://www.gmmetaldetectors.com/metal_detectors.php

Obviously i am not good informed about whole the GM production line and all the series.
It is not miracle at all; i was not interested in those until last winter when all of the sudden i got chance to inspect above mentioned models.
Winter, lot of annoyance, so i did what i did and nothing more than that.
But i can warmly suggest you this coil:

http://www.goldenmaskdetectors.com/coil_details.php?id=5&lang=en

From all the coils i tested; that coil i like the most.

[SVEN1]

Guess my coil thinking is flawed?
They offer the coils in either 8khz and 18khz.
So like Minelab Exterra if you want to use two frequencies you need to have two coils, then use the toggle switch on the control box to switch between them. https://thrace-detectors.com/product...olil-23cm.html

http://www.gmmetaldetectors.com/metal_detectors.php

[ivconic]

If using the Golden Mask coils.
Do we have to use a single frequency coil, or the two frequency search coil.
If using the single frequency coil, it would be just a matter of using the two diff. caps and the switch similar to the Tesoro mod?
[ATTACH]37360[/ATTACH]
And does the single frequency GM coil have the latitude to be used between 8 and 18khz?
I just want to make sure when buying a coil, I get the right one.

Or do we need to buy two different single frequency coils 8khz and 18khz to be able to use the two frequency selector toggle switch?
By the way where is the best place to pick up a new or used GM coil that will ship to Canada?
I am kind of leaning towards the smaller coils 10" and smaller

I am pretty confused with your question, because i didn't knew that there are "two frequency coils" at all!?
Last winter i had on the bench 4 original GM coils, came to me with GM1+ (one older in larger box and one newer with small box and UK flag on front panel), GM4WD and latest GM5.
All coils were interchangeable between detectors and all performed the same on each detector, also on all frequencies.
Must point one thing; all coils were from the latest series, newer design.
So i don't really know what to answer to you.
I haven't followed earlier models and series of GM coils, maybe those from earlier series were somewhat different? Can't tell.
One thing is for sure, if you want to be sure that your diy detector made by schematics which are posted here will work; obtain newer type of GM coil.

[SVEN1]

If using the Golden Mask coils.
Do we have to use a single frequency coil, or the two frequency search coil.
If using the single frequency coil, it would be just a matter of using the two diff. caps and the switch similar to the Tesoro mod?

And does the single frequency GM coil have the latitude to be used between 8 and 18khz?
I just want to make sure when buying a coil, I get the right one.

Or do we need to buy two different single frequency coils 8khz and 18khz to be able to use the two frequency selector toggle switch?
By the way where is the best place to pick up a new or used GM coil that will ship to Canada?
I am kind of leaning towards the smaller coils 10" and smaller

[ivconic]

The data for the coil what
Rx-?
Tx-?

I've posted earlier.
Golden Mask coils with several dimensions are varying in ranges: TX=0.55 - 0.7mH and RX=5.5-6.5mH
Golden Mask coils are best for this type of detector.
There is additional winding or few in series with TX coil.
Explained earlier, read topic from the start.
Cheers!

[bandito]

The data for the coil what
Rx-?
Tx-?

[ivconic]

Same as this one?
http://www.szwirelessheadphones.com/...show.asp?p=136

I suppose so.

[joop]

Same as this one?

http://www.szwirelessheadphones.com/product_show.asp?p=136

[ivconic]

As for the "wireless" headphones; neat little thing was done: