My take on the HH2

[waltr]

DO you remember your PIC audio frequency?

It is in the source code comments, line 590.

;---------------------------------------------------------------
; lowest 8 bit NCO1INC value sets frequency from 15Hz to 1945Hz
; NCO_center at 0x7F is 969Hz
;

[h9361]

It is in the source code comments, line 590.

;---------------------------------------------------------------
; lowest 8 bit NCO1INC value sets frequency from 15Hz to 1945Hz
; NCO_center at 0x7F is 969Hz
;

Thanks.
Sorry, i have a question about using wire. I'm going to use ethernet wire (STP, shield twisted pair, 24AWG) for HH1 coil. Do you think i can use shield of the wire as a shield from outside electricalinterference?

[waltr]

Thanks.
Sorry, i have a question about using wire. I'm going to use ethernet wire (STP, shield twisted pair, 24AWG) for HH1 coil. Do you think i can use shield of the wire as a shield from outside electricalinterference?

I used ethernet CAT-5 wire. Works fine.

[h9361]

I used ethernet CAT-5 wire. Works fine.

Thank you dear Walter for your Info.
Do you remember the following details?
1- Your Coil size
2- Number of turns
3- Inductance Value
4- Your damping resistor value

[waltr]

Thank you dear Walter for your Info.
Do you remember the following details?
1- Your Coil size
2- Number of turns
3- Inductance Value
4- Your damping resistor value

All that info is in this thread. Please READ the entire thread.
I would need to go back through this thread to answer those questions.

[h9361]

All that info is in this thread. Please READ the entire thread.
I would need to go back through this thread to answer those questions.

OK thank you. I have read your thread, i will again read it.
Dear Walter, i had several tests with TDI SL. As you know, it has three modes 1-High 2-All 3-Low
I tried to remove ferrite rode in ALL mode via its Delay and GB pots, but i couldn't do it. Unfortunately, its Audio in ALL mode is very unstable and it produces unpleasant sound (it's not a clear sound). So, i had to change its mode to Low. In this mode, it's stable but unfortunately it removes many metals wrongly! My result is that users have to use TDI in ALL mode but they also must tolerate its unstable sound. As a result (from my view), i think GB of TDI is not very nice in ALL mode, while GPX series has a better GB performance.
I remember you have said that you have been able to remove ferrite rode by your GB, is that right? Can you tell me about performance of your GB?
Thank you.

[h9361]

See the following videos about GPX 5000. They can help users to learn more.
Video-1: about its circuit and TX pulse width
Video-2: about its battery

[waltr]

See the following videos about GPX 5000. They can help users to learn more.
Video-1: about its circuit and TX pulse width
Video-2: about its battery

Again posted in wrong thread. This thread is about mod'ed HammerHead not GPX.
There is a GPX thread to post in.

[h9361]

Again posted in wrong thread. This thread is about mod'ed HammerHead not GPX.
There is a GPX thread to post in.

OK.

[h9361]

Hello dear Walter
I have a question about TP9 in HH1.
According to Mr. Carl's article, TP 9 must show 0 volt.
I tested it and the point is 0v. My question is that can i use a voltmeter over the point so that i see the 0 volt in the meter? Can you guide me what type meter ac or dc i should use?
Thank you

[waltr]

Hello dear Walter
I have a question about TP9 in HH1.
According to Mr. Carl's article, TP 9 must show 0 volt.
I tested it and the point is 0v. My question is that can i use a voltmeter over the point so that i see the 0 volt in the meter? Can you guide me what type meter ac or dc i should use?
Thank you

Hope I am looking at the same schematic as you....
TP9 is the output of the SAT stage. Pot R31 is adjusted for Zero Volts at TP9.
A DVM works fine to do this adjustment.

This SAT stage is AC coupled by C19 so in theory (ideal opamp) its output should be zero if no change of Voltage is on TP5. However, no opamp is ideal and will have input bias offset error. R31 corrects for for this error.

BUT, pot R31 is best panel mounted which is then field adjustable as the 'threshold'.
The way to use this is power on the HH and turn pot R31 until the audio starts chattering. Then turn to back slightly to have nearly quite audio. This is the most sensitive setting and the smallest target with cause an audio response.

So in the end there is no need to use a DVM to measure and set R31 for zero at TP9.

[h9361]

Hope I am looking at the same schematic as you....
TP9 is the output of the SAT stage. Pot R31 is adjusted for Zero Volts at TP9.
A DVM works fine to do this adjustment.

This SAT stage is AC coupled by C19 so in theory (ideal opamp) its output should be zero if no change of Voltage is on TP5. However, no opamp is ideal and will have input bias offset error. R31 corrects for for this error.

BUT, pot R31 is best panel mounted which is then field adjustable as the 'threshold'.
The way to use this is power on the HH and turn pot R31 until the audio starts chattering. Then turn to back slightly to have nearly quite audio. This is the most sensitive setting and the smallest target with cause an audio response.

So in the end there is no need to use a DVM to measure and set R31 for zero at TP9.

Thanks for your explanation.
I can easily see the oV with DVM, but i'm going to use a separated voltmeter module so that we can see the 0V.
Do you think i can use such module (DC or AC)?

[waltr]

Thanks for your explanation.
I can easily see the oV with DVM, but i'm going to use a separated voltmeter module so that we can see the 0V.
Do you think i can use such module (DC or AC)?

That really will not work since the SAT output goes positive and Negative. You need a Voltmeter that can read + and - Volts DC.

[h9361]

Hello
Dear Walter.
Please see the attached, can you guide me time delay between S3 (EFE-1) and S4 (EFE-2), shown by arrow? I think it should be 5-25 microsecond, is it true?
Thanks.

[waltr]

Hello
Dear Walter.
Please see the attached, can you guide me time delay between S3 (EFE-1) and S4 (EFE-2), shown by arrow? I think it should be 5-25 microsecond, is it true?
Thanks.
[ATTACH]55243[/ATTACH]

Correct. Should be the same as delay between S1 & S2.