Hammerhead ready but probs with audio

[Pilot68]

Hi all,

i was searching for mistake some days now, but i'm really confused about my problem.
I've built the HH2 with option 1 and option 2 switchable. In both cases audio doesn't work like it should.
In VCO-mode i have no tone (Threshold R31 with no effect) and with metal near the coil (and IC8 in saturation) full pitch but nothing between.
The output of IC8 (Pin 7) looks ok, because there signal is moving from GND to nearly + 5V according to objects distance, will say circuit is working straight to this point.
In non-VCO-mode it's similar, either no tone or full loudness, nothing between.

Maybe i am wrong with my NE555 (CMOS-type TS555) ?
But this would not explain the misfunction of non-VCO-mode.

I guess it'll be something wrong around Q5 / Q6 but i checked many times now, and the Q's are still ok.

Please help, i also want A WORKING HH ;-)

(Sorry for my english)

Jörg

[Pilot68]

Update

Hi, just found it,

my mistake : IC7c was not switched on in VCO-mode (should be active all the time in VCO-mode). VCO-mode works now fine, treshold is adjustable.

Sometimes IC6 catches the 50Hz of our public powernet, so the tone sounds not nice, but detector is still sensitive. Should be better outside, also i use a power-supply instead of batteries at this testing-procedure.

But i got not working non-VCO-mode. Maybe a problem with signal N7 also. This time in non-VCO-mode N7 (and IC7c) is active while second delay time is running (produced by a µP). That correct? (Carl)

Bye and thanks
Jörg

(first tests in "noisy home environment": 1Cent-Euro-Coin in 12cm / 15cm-Coil)

[Pilot68]

Pictures

Hi, this is my version of HH:

all timing, switching VCO-mode and switching single/difference-mode is done by a µP (AT89C4051).
Display shows frequency, first and second delay-time, main pulse, sample-pulse, and used memory (20 memories to save settings availiable),
most of components like R's C' and Q's are on the layer-side of pcb (SMT).

Another pic shows some of my homemade coils.

Bye
Jörg

[Carl-NC]

For the non-VCO chopper signal (N7), I was limited in my choices so I used the secondary delay signal. Since you have a uC, you can create your own chopper signal, and move it away from any critical signal time.

Very colorful coils! And I like your design... very close to what I am (slowly) working on in HH2.

- Carl

[Pilot68]

non-VCO-mode

Hi Carl,

thank you for reply.

It's exactly what i did, N7 is chopped while delay2-time. But doesn't work. I'll check it out next days and see what's wrong. Has anyone used non-VCO option with success?

And if of interest, i can send schematics and layout / software.

Bye
Jörg

[1843]

Atiny4

Hi Jorg,
Why you don't make Atiny4???
It is very powerful!

[Pilot68]

Hi 1843,

it's right, the avr-risc-family of atmel is very powerful, but i used only 8051-compatible µPs so far.

All my macros i.e. for controlling a lcd, output of tones , making exact pauses are all written for this µP-type.

Bye
Jörg

[Mustafa]

Hi Carl,
And if of interest, i can send schematics and layout / software.

Hi Jörg,
Is it possible to post only your schematics?
Your mod is just what i'm looking for, but instead of 8051-compatible µPs I will use microchip ones.
Regards,
Mustafa

[aft_72005]

Hi 1843
Ary you built atiny 4 ?

[GREEB]

Hi 1843
Ary you built atiny 4 ?

helo im new pleze can you give me the circel

[cko47]

Hi Jorg!
Do You can send to me your schematic. board and software?
My email [email protected].
Thank You