TD3X ( pi )

[Old cart]

Fantastic. So the boards you made already have this mod on them? Do you have a parts list for all the parts?

[eclipse]

The diode is missing but easy to install. I will provide the last schematic version & parts list.

[nickel_n]

The diode is missing but easy to install. I will provide the last schematic version & parts list.

Is there a chance for rest of us mortals that you will post the lay file too?

[eclipse]

nickel_n, I don't intend to post the files. I will have few boards that I could sell for few bucks, if you'd like to build it you can take advantage of that.

[nickel_n]

nickel_n, I don't intend to post the files. I will have few boards that I could sell for few bucks, if you'd like to build it you can take advantage of that.

thank you.i would love one.
can you put my name on the list please

[eclipse]

thank you.i would love one.
can you put my name on the list please

Boards have arrived but I will be able to post on Monday, 28. I'm on a vacation for the holidays. Send me PM with address if you'd like one.
Comes with no guarantees it will work, on your risk
Btw I haven't seen them yet if they are OK...

Cost for board with regular airmail 7.5$, or 6$ with economy mail (non-trackable and no bragging rights if it gets lost).

[eclipse]

Boards have been sent. They should arrive in 3 weeks or so. I will prepare parts list soon.

[6666]

PM sent, thanks eclipse.

[6666]

Eclipse please look for PP payment and postal info in PM, thanks.

[daverave]

ive modified my detector to a variable pitch similar to TD3X but i also have a rise in amplitude cause i wanted both

[eclipse]

Sounds sexy. What did you use - the emitter degeneration or vactrol as the original TD3X ?

[daverave]

i just modified the 555 audio circuit and used electronic switch and works very well.

[6666]

i just modified the 555 audio circuit and used electronic switch and works very well.

Is it something that you can show us ?

[eclipse]

I found nice old program to help calculate 555 timer such as the one used here (modified version with one 555), give it a try.

[eclipse]

I had the opportunity to finish the modified board today. It works.

Few first impressions: first of all about the coil, what Ivconic said few pages back....- I tried mono coil wounded from a regular 0.5mm enamelled wire and it failed miserably...

So next I tested 300uH 1R coil 38cm dia - works much much better (PVC wire 0.5mm2). It's not tightly packed, it's somehow scattered around the place but still it works.
I want to try higher inductance coil, bigger wire diameter probably and test it with it.

Right now detection depth is not big, I hope I can increase that, or just make a larger coil ...

The good - It's very responsive - I mean no lag or lack of sound when swinging small & big object back and forth, and even with very fast swing - I mean baseball speed - I'm really glad to see that cos other PI machine I have built lately do that = really annoying.

Now for the bad part - sounds is itchy, scratchy and unpleasant. Well no so bad.. but still not so pleasant and smooth like the vactrol stuff there of Dooley's original deal.
It just starts and ends scratchy and rough, constant bleep also suffers but could be okay if volume is low.

Problems - I have a overheating problem with the LM317 (in my case LM33. It burns the **** out of it. The Mosfet is stone cold and the reg is just burning.

Haven't installed the diode (Mosfet insulation diode there) just to see if there's any real difference with / without it.

Pots will need a ground connection with their housings.

Growl control works! It helps to adjust the sound.