HHI rev C thru-hole boards available now !!

[silverdog]

As discussed in another thread I have organised a short run of HHI rev C thru-hole boads

Well they arrived this morning and look very nice !!

I only have 20 available and these will go on a first come first served basis

prices are

$12 US for a single board shipped worldwide
$20 US for a pair of boards shipped worldwide

PM me for payment details if interested

[Captain]

Hi I sent you a PM
Thanks for doing this

Terry

[greybeard]

thanks mate
pm sent for a couple of boards
rod

[WM6]

As discussed in another thread I have organised a short run of HHI rev C thru-hole boads

$20 US for a pair of boards shipped worldwide

PM me for payment details if interested

Great news! Thank you!

You have PM for two PCB from me.

Best regards

[6666]

Thanks SD will send you a PM for two boards

[Captain]

I received my two boards yesterday and they are perfect!

Thanks for ordering these boards
Terry:-)

[silverdog]

Glad to hear the boards have been arriving safely, all around the world !!

When finished, could everyone post some pictures of their completed boards please ?

I have started mine and am currently waiting on a few parts

[WM6]

Thanks to silverdog kind initiative, I received my two boards in past week (despite street address and house No. missing) and must say that all works with PCB-s are highly professional done.

I wish happy building this interesting PI with wide set of control possibilities to all new PCB buyers.

[6666]

I got paypal to work today, sent off my order to SD

WOW wm6 you must be friends with your postman

[silverdog]

6666 - your boards are in the post

WM6 - glad to hear they arrived - sorry about the address, unless you include it in your message to me I can only send to the address paypal shows - and I am not aware if that has missing details or not, lots of different formats around the world !!

[GoldenKiwi]

Hi Silverdog, mine arrived today! Many thanks for sending so quickly... I haven't even finalised my parts list yet!

The quality of the boards looks excellent.

I plan to build up over next week or two and post pictures when done.

Cheers
GK

[Vortxrex]

Hi everyone, just joined the forums today. I don't have access to the PM part of the forum for some reason. I am very interested in ordering a few of the hammerhead thru-hole boards from Silverdog

Dave Frank

[silverdog]

Vortrex

I have sent you a PM with details for ordering the boards

Silverdog

[Qiaozhi]

Hi everyone, just joined the forums today. I don't have access to the PM part of the forum for some reason. I am very interested in ordering a few of the hammerhead thru-hole boards from Silverdog

Dave Frank

Now you have made your first post, it should magically start working.

[GoldenKiwi]

Would love some help with calibration

Hi, if possible I love some help with calibration...

The boards are great and my build seems to have gone pretty smoothly, except I was unable to set the offset using R18 as expected, and hence didn't complete calibration during build. I realised this would be a problem, but I was overly keen and continued regardless.

I wound a basic shielded coil similar to that in that in the build article (except I only have 0.25mm, and didn't shield the short wires to connect it) and the good news is that it does actualy work, and I can detect objects like coins and my small screw drivers from a few inches. :-)

I have purchased some polyethelyene spiral wrap and some shielded cable and have wound a tidier coil ready to test once calibrated.

I have no idea what my settings are (mid range I believe), and I'm in a noisy indoor environment (computers and fluoro lighting) and haven't yet put it inside a shielded encolsure... so I do get noise and instability but I expect that at the moment.

What I do experience however is a constant high pitch tone, and an inability to vary the threshold at all. I assume this is probably because I haven't calibrated and have signficant offsets.

Today I have attempted to cailbrate following the suggestions here;
http://www.geotech1.com/forums/showthread.php?t=13267
- I have disconnected my coil
- I have shorted pins 1<->2 and 3<->4 on IC7(a/b)
- I vary R18 and measure TP4 (using Fluke 10 DMM.. its all I have at moment)

My results are as follows:
NE5534 ranges 0.464 through 0.752
..substituting...
LM318 ranges -1.412 through -1.703

Neither opamp can be adjusted to near 0v, and I have no idea why.
The supply voltages are -4.96 and +4.95

All components are new and not substituted with anything different. I have built according to Option 1.

I'm a beginner so I expect I have done something silly! Can anyone see any obvious flaws looking at my picture, or can anyone come up with any suggestions to help troubleshoot?! I dont have a scope at the moment, but intend to purchase one to take this project further.

Any assistance would be much appreciated!

Cheers
GK