New Metal Detector book!

[bernte_one]

hello appie excellent

first i have only seen photo by direct click on attachment and i thought the design must be from you
nice
would you please upload layout files later

many kind regards bernd

[ivconic]

As usual; splendid work from you Ap!
Always nice and neat work!
I haven't made Raptor yet but knowing his author; i bet it is excellent design!
Might be that i will make it in this winter myself!
Cheers!

[Davor]

There is a little room for mods

[Qiaozhi]

There is a little room for mods

The Raptor design follows the same concept as Hammerhead. It was conceived as a learning platform, with the idea that others may like to improve the design, once they understand the general VLF methodology. So, you are welcome to go ahead and make as many changes as you like. Raptor already works pretty good in the field, but there are many things that could be tweaked. That was always the idea.

One day I'm going to start work on Raptor II ... so be prepared!

[ApBerg]

hello appie excellent

first i have only seen photo by direct click on attachment and i thought the design must be from you
nice
would you please upload layout files later

many kind regards bernd

Hello Bernd,

The design from the Rapror is from George/Carl , I only made a copy in Sprint Layout..
( have you seen that Silverdog has some nice boards for sale !)

I you use the sprint file you have to check things !! the latest version I made is in Sprint Layout 6, most wil have Sprint Layout 5... so I have included the version 5 pcb in the zip file.

Best regards.

Ap

[bernte_one]

hello appie

i know this detektor from my book but i love your adaption into sprint layout like everytime
(baracuda, surf pi 1.2, surf xx ....)
you have a good hand for design


many many many thanks for your support

[6666]

Hi Ap great work on raptor

[reg85]

hi,i have one question...i read in the book in the raptor project the capacitor of 470nF are polyester,but the others?are ceramic or polyester?
thank you

[Qiaozhi]

hi,i have one question...i read in the book in the raptor project the capacitor of 470nF are polyester,but the others?are ceramic or polyester?
thank you

Ceramic capacitors are good for RF circuits, whereas polyester are better for general use. You can probably use either in the Raptor design without noticing any difference. None of the designs in the book use critical components, and these (or a suitable substitute) should be available locally. They were also purposely designed to use "nice numbers", and to be relatively simple to replicate.

[mschmahl]

I have finished the raptor.
I use a tesoro 11" DD coil 5-pin. TX is 5.99 mH and RX is 5.56 mH. After a lot of "trial and error" i have managed to get a good depth. But i think ground and disc is on the edge of the stting range and it must be more on the left on RX for proper working. For my conditions here it is working. Ground doesn´t have a influence of RX (a bucket full of soil in front of coil doesn´t show a reaction in RX) and iron comes throug only with crackling sound for big items. Here are my curves. Look´s they right for a DD coil?
Disc

Ground

TX+RX

[Qiaozhi]

I have finished the raptor.
I use a tesoro 11" DD coil 5-pin. TX is 5.99 mH and RX is 5.56 mH. After a lot of "trial and error" i have managed to get a good depth. But i think ground and disc is on the edge of the stting range and it must be more on the left on RX for proper working. For my conditions here it is working. Ground doesn´t have a influence of RX (a bucket full of soil in front of coil doesn´t show a reaction in RX) and iron comes throug only with crackling sound for big items. Here are my curves. Look´s they right for a DD coil?

Is your ground balance pot not at mid setting?

I also see that your TX waveform looks a little distorted. Unlike the Tesoro oscillators (which are based on Colpitts) the Raptor oscillator should provide a good clean sine wave. Have a look at Fig. 9-18 on page 103. What is your TX frequency?

The design was tested with many different sized coils, from 4" up to 12"x10" elliptical, and with both concentric and DD. It was possible to ground balance in all cases.

[mschmahl]

My ground balance pot is almost completly to the right, also my GB-Offset.
TX is arithmetical 14.5 kHz and RX 16.28 kHz. With 10 kHz TX i get only 20 cm for my silver ring not 30 cm as with 14.5 kHz.

[Qiaozhi]

My ground balance pot is almost completly to the right, also my GB-Offset.
TX is arithmetical 14.5 kHz and RX 16.28 kHz. With 10 kHz TX i get only 20 cm for my silver ring not 30 cm as with 14.5 kHz.

That's why your GB setting is over to the right. The circuit is designed to work at 10kHz.
Is the TX waveform distorted when tuned to the correct frequency?
The detection distance for a Victorian penny should be 12" (30cm) and for a Euro around 10" (27cm) when using a 9"x8" elliptical coil from Tesoro.

[mschmahl]

With 10 KHz was the TX waveform not distorted. Only the deep was not good.
I think i will change the cap´s for the right frequencies.
Are the sample point´s on the matching range for a DD-Coil?

[Qiaozhi]

Are the sample point´s on the matching range for a DD-Coil?

Your sample pulses appear to be in the right place for a DD coil.