Delta Pulse

[seras05]

This is the coil

[seras05]

This is my dp2 work ok

[eclipse]

The device is working now. Basically i didn't have lf357 so i used Opa637 and ad845. Those 2 didn't work also had 1 burnt diode. Im testing the device with 22cm coil and depth is very good 60 cm beer can, 120 cm for 35cmx25cm tray. Ill be making large coil next perhaps 35-45cm.

[mohandes]

hi this is my DP I build 2 work ok the coil is 76x76 1.3 mH and 4.5 ohms
i cant post images can you helpme

your coil have more.400 to 550mkh and res 2 to 4 ohm.
can you tell us about your detection?

[seras05]

i can thank you

[seras05]

hi this is my DP I build 2 work ok the coil is 76x76 1.3 mH and 4.5 ohms
i cant post images can you helpme

[roccocoin]

Hello everyone Forum, I would like to know if the delta pulse 2 and can eliminate some external potentiometer, but replace with gari resistors internal trimmers, if you can do what I could cancel externally? best regards

[kt315]

Mege, I write you here.
IFR740 - OK
VD15 - OK
VD9 - OK
VD8 - not OK. burn.
Guys, I ask you AGAIN to MAKE THE SHIELD OF THE POTS AT FIRST -! SHIELD!
I HAD wrote about that but seems you AGAIN do not wish to read that I post.

[eclipse]

I am having some troubles to get delta pulse running. I have sound but its higher frequency than it should be. Pots are working - i.e sound changes when i adjust discrimination pot. Pushing reset button stops the irratating sound for couple of seconds than its starts again. Interesting is that when turned off the last 2 seconds it gives the right sound. All components were checked before soldering.. But this may be the result of heat when soldering, maybe a transistor not working.. Will see.

[eclipse]

What coaxial cable is best to use to connect the coil with the board?

http://www.rfcafe.com/references/electrical/coax-chart.htm

I've seen on this topic people using RG58, I can also find RG211. How about specs?
What is the best value fro Z0(Ω), DielectricType, dB/100 ft @400 MHz, I know it's best to have lower capacitance.

[kt315]

briefly, you have to keep R37 with the schematic default value.

all the best

[eclipse]

There alot of trash parts these days. I've compared some parts from sites like ebay, aliexpress and digikey/mouser prices. It's 2-5 times cheaper on aliexpress and ebay which means
that these guys sell knock-offs fake Ti, AD etc.. It's reasonable to think that you small local shops prefer to get these parts for less - hence the low quality. I always try to buy parts from the big players -yes it comes more expensive and takes alot more time than going to the local shops but can save alot of nerves and stress.. (or use old TV parts like other folks do )

I got a question:
I won't be using uA meter, so should I bridge the +/- pins of PA1 and remove R37 (560R)? or should I keep R37 with the default value?

[calebsone]

I wonder that board looks a lot like mine I mean the heatsinks I would check the voltage diodes I think d7 d8 remember my problem was fake ones.I am saying maybe that guy bought from where I did because my dp did work till I turned it up and burnt out the diodes

[eclipse]

Looks nice, hope you can find what's wrong with it. It's good that almost all ICs are in sockets

[kt315]

this board was sent to me for repair. I will tell you step-by-step what I do you can fix DP yourself if meeting a problem. have to say soldering seems OK, very clear, and no notes to it.