PI discussion

[Carl]

There is an excellent discussion on PI detectors at the Findmall "Classroom" form. It was intended to be a how-to class for users but has turned into detailed technical and design issues, due to the fact that Eric Foster is participating.



PI Classroom

[chris]

Re: PI discussion

I recently built the Mark Stuart P.I detector. As stated in an earlier post, it appears that VR-1 will not operate as shown in the schematic. In addition, IC-4 does not appear to have a 9V power connection, on the schematic, or on the PCB. Has anyone else built this board?. Any suggestions or help appreciated. thanks.

[Carl]

Re: PI discussion

Looking at the PCB IC4 has pin 7 connected to +16, not pin 9 to +9v as the schematic indicates (there is no pin 9!). Conversely, the coil is connected to +9 on the PCB, not +16.

I redrew the schematic from the original which was too poor to post, so I need to check the original. In any case, the document needs fixing. Thanks for letting me know.

- Carl

[chris]

Re: PI discussion

Are there any changes to be made to the Mark Stuart PCB? any websites or further support for this design? thanks

[Carl]

Re: PI discussion

>Are there any changes to be made to the Mark Stuart PCB? any websites or further support for this design? thanks

Other than what I've posted, I don't know. Mark Pauls came up with the PIC code, and Magenta still sells the kit (I guess). A few people out there might be messing with the design. I can fix the PCB if there's an error.

- Carl

[chris]

Re: PI discussion

Was the PCB made from the schematic?, which came first? if so it would explain errors on the board. Any way to get a copy of the original schematic? thanks

[Carl]

Re: PI discussion

I'll dig up the original schematic and post it. Might be this w/e before I can get it as I am heading to Atlanta today. But the PCB normally follows the schematic.

[Roland Hutter]

Re: PI discussion

Hi Chris,

first sorry for my bad english...
I built Mark Stuarts PI-Detector:
1. The schematic has mistakes
2. PCB is okay.
3. VR1 doesn't work ! Don't use it, instead use VR2 for sensivity(10-Gang-Potentiometer)
4. The pic-file has mistakes and didn't work.
I fixed it.
5. In the pdf-file are not descripted all the
features of the pic (for example adjusting
receivetime, pulse time and so on by push-switches.
Please send me an email if you want to have the corrected pic-file and schematics.

Bye

Roland

[Roland Hutter]

Re: PI discussion

Hi Carl,

your site is great !!
Where do I find Mark Pauls' new file pi84-4r.asm ? I only find his additional hints.
BTW Mark's email-adress doesn't work.
Thank you.

Greetings

Roland

[Carl]

Re: PI discussion

>Where do I find Mark Pauls' new file pi84-4r.asm ? I only find his additional hints.

The latest version I have is on the Stuart page. Click on the link for "PIC Assembly Code" which is actually rev 4.

- Carl

[chris]

Re: PI discussion

Roland I tried 2X to email you, and server said message was undeliverable. Yes please email me any revisions on circuit, hex file or any other info regarding stuart PI. I am glad to find someone else who has built this detector. I got it working using a hexfile sent to me by Mark Pauls, and revision to op amp input circuit, however I have had mediocre performance.
Thanks Chris