show completed HH detector

[Clondike Clad]

Ok how about showing your completed hammerhead detectors

[Unregistered]

Ok how about showing your completed hammerhead detectors

Carl has sent his HH picture at one threat. You can find it and see.
I hope this help.

[exciter]

Hi,
thats my.
Case needs some paint

http://picasaweb.google.de/tertomium/Detector

[joecoin]

Finally in the box.

[GT Blocker]

Finally...

OK, here's mine,







Here's my 9"x 3" DD 'test' coils for the dual coil configuration. So far I can get down to 10uSec. ATM, I'm making a co-planer to fit the 8" round housing in the pic above.



Notes:

The strange 'pink thing' in the first pic is a DIP carrier with a bit of balsa wood to hold the very tiny SMD LMP7716 dual op-amp. The battery is an 11.1v 3a lithium fed from a belt/fanny pack through the rear of the shaft up to the box. The button on the shaft is the AutoTrack switch. The 'kinked' pot at the rear isn't in place yet (duh).

The shaft and round coil housing are from a $20 (+$10 S&H) Ebay "Treasure Hunter All Vision Pro" VLF (BTW - the coil housing halves are easily separated giving you the co-planer coil forms, the coil housing, and the shaft).


So anyway...the weather is nearly cool enough in AZ to go test this puppy, and that's cool enough for me!

[joecoin]

Looks good. I'm fielding testing this weekend. Going to go relic hunting at a circa 1850's shipyard.

[GT Blocker]

Joecoin? So what happened?

Hey there Joe,

You never followed up on your tests. How did it go?

Since I posted and said that I was ready, I decided that I lied. I found that even testing the detector in the backyard was a pain due to the belt mounted battery. So.... I fired up the vacuum form machine and made a box for the lithium batt to fit between the armrest and grip. MUCH better, the balance is better as well as mobility. Here's a pic:



The coil is now in the round housing and is a co-planer concentric (dual coil). The 'extra cable' (6") is to allow for a bit more extension when I lengthen the shaft. Sample times are now at 8.5uSec, thanks to BBsailor, Tinkerer, et al.
Along the way I also made the pre-amp two stage (with a high pass filter via R22/C16 as suggested by J.L. King).
Here's the dual pre-amp I'm using atm:



After that I added an 8th order low pass Bessel filter between the integrator and post amp:



And finally, I decided to add a flashlight. !!!!??? What? Yeah, a 'headlamp'.
If you've ever been caught out close to camp after dark, but not close enough, you'll see the reasoning. WTH, you're carrying a plenty of power to light a monster LED, even if the detector is getting too low on power to be reliable. One LED, one switch, one resistor....no biggie.

[joecoin]

GT,

Well, I tested my HH in the backyard first and got very poor depth results. Then I started to smell that smell we all know and love, burnt semiconductor. My Q3 went thermal on me. I was using the ANS surplus mine sweeper coil. I replaced Q3 and ran some bench tests, she runs fine without the coil connected, gets too hot after about one minute w/the coil.
My TP4 waveform is not even close to being proper.
Gotta get back to it now during winter, I've been working on a basket case Fisher 1280X in the interem.

[gef12]

My HH

Ok here goes.. my HH unit.
Can detect with the 10 inch eliptical mono coil (coiltek) 1 grm gold nugget at 4 inchs, 25c quater 6.5 inch, 2 cent oz coin 7 inch, mans 9ct gold ring 9 inch.. These are air tests.
Happy with it thus far.
Geoff

[learner]

Geoff,

a job well done mate.

is your control box made of aluminium ?

I am have trouble deciding if i should make my own or by one from some were.

but were would you buy a control box??

anyone got any idea's??

I'll post this at porspecting oz site too.

cheers
Dave

Handles:- Learner & detector NT

[gef12]

HI Dave
Ye control box alluminium .. I got it from the states somewheres as was hard to source in Australia ... with the size I wanted and type.

[BobCat]

It's a bird it's a plane

Hi all

The old Gold Master quit working many years ago but today with a new Hammer board for a hart and new coil in the old housing she lives again.
The meter was hooked up at TP9 and configured the same as Gary's pulse 2 detector. The battery check switch is now auto track on off and 12V battery check. I made a custom board to hold a second op amp for the two stage preamp. I took it out for a test run found a couple of coins a lot of junk and one week signal I just had to dig at around 10 inches I found a small 2 inch nail. Can't wait to get the old girl out to some better places and do some good hunting.

Bobcat

[Carl-NC]

That's pretty clever, Bobcat. People will be laughing at you for swinging a 1972 detector, but you can have the last laugh!

- Carl

[Joe(TX)]

Hi all

The old Gold Master quit working many years ago but today with a new Hammer board for a hart and new coil in the old housing she lives again.
The meter was hooked up at TP9 and configured the same as Gary's pulse 2 detector. The battery check switch is now auto track on off and 12V battery check. I made a custom board to hold a second op amp for the two stage preamp. I took it out for a test run found a couple of coins a lot of junk and one week signal I just had to dig at around 10 inches I found a small 2 inch nail. Can't wait to get the old girl out to some better places and do some good hunting.

Bobcat

.........Bobcat....how about some Pic's especially inside the box!!??.......I like your idea!!.....................Joe

[Joe(TX)]

.........Bobcat....how about some Pic's especially inside the box!!??.......I like your idea!!.....................Joe

..............I just bought a HH PI.......all it has is the coil and the circuit board and the switches/control knobs........need a case........ was going to buy a new one ..............but liked the idea of using a pre-existing case from an obsolete detector............may have to use one of the big box cases from Whites but maybe I can use a case from an Wilson Usika Chief.......just waiting on the detector to arrive to decide exactly what I may do!!......Joe