Voodoo Main Discussion

[lamoiz]

r66 hs .. it cooked over a low heat .. I think my 8r hp should not be adapted .. finally I will measure it, because the inscriptions have disappeared, maybe I was wrong.

[lamoiz]

George, the 33r resistance on the hp route, almost gave up soul, due to overheating. My hp is 7.7r (measured), do you think I can replace it with a 100r? Or a 33r 1w? I won't be the only one having this problem, what do you think?

[lamoiz]

nasal detection (without covid of course), is a good fault detection system ....

[surfdetector]

R30 tp3 tp1..mini 1.6v .. impossible to zero, there's something I'm doing wrong ..

Were you able to zero this out?

[lamoiz]

Were you able to zero this out?

with the osciloscope I went down to 700mv ..not succeeded in doing better ...

[MartinB]

Internal dimensions of the shell are:
Front to back - 293mm
Side to side - 260mm
I have then allowed a further 15mm all round to house the coils

[MartinB]

hi Godigit, the TX coil is 430uh, and its damping resistance @ 650r. wire 0.8 silicone. The two RX are respectively 5.5 mh or a series total close to 11mh ... wire 0.18; all tuned with a capa 21.6 nf (@ 20 ?) .. the purpose being to have a frequency of 10.5 khz, (10.32, to be precise)

Hi lamoiz
Are you using silver plated copper wire with silicone insulation or plain copper with silicone insulation? Thanks for the information on your coil

[Qiaozhi]

George, the 33r resistance on the hp route, almost gave up soul, due to overheating. My hp is 7.7r (measured), do you think I can replace it with a 100r? Or a 33r 1w? I won't be the only one having this problem, what do you think?

I assume you're referring to R66? Personally I didn't fit a speaker in the finished detector, but used high-impedance headphones. During testing on the bench I used a 50 ohm speaker. If you're using an 8 ohm speaker, then R66 could potentially get hot, and should be replaced with a higher wattage device. You could also try increasing the resistance to 150 ohms.

[lamoiz]

I assume you're referring to R66? Personally I didn't fit a speaker in the finished detector, but used high-impedance headphones. During testing on the bench I used a 50 ohm speaker. If you're using an 8 ohm speaker, then R66 could potentially get hot, and should be replaced with a higher wattage device. You could also try increasing the resistance to 150 ohms.

yes post 407, r66.
I'll put a 150r to see, or a 33r 2w .. it will be heating for the winter.

[lamoiz]

Hi lamoiz
Are you using silver plated copper wire with silicone insulation or plain copper with silicone insulation? Thanks for the information on your coil

yes, I think it is, because it is an old spool of thread that I have had in my workshop for a very long time, and there is no longer the informative label. silicone and silver color.

[dfbowers]

I decided to go forward with the Voodoo project but will probably start from scratch with a coil since I plastic shells everywhere.
Question for George.. What kind of lead wire from the coil to the box? I have used two shielded pairs for some project, others I have used a high quality USB2 cable. The only difference I have seen with past projects has been that the coil will balance at a slightly different place.
Don.

[MartyJ1963]

Hiya George,,,I'm having a little problem with my build. I am getting +5v at TP14,,but I'm only getting 0.720v at TP15. I bought 2 x programmed PICs from Andy (Silverdog) and though I totally trust his programming skills I tried both PICs and still don't get the correct voltage at TP15. I re-programmed one of the PICS with the HEX you posted and still not getting the correct voltage at TP15. I have checked and double checked all the components I installed for correct placement and values,,I've checked for solder bridges and dry joints and I've totally cleaned my PCB. Could you tell me what I could try next please in the fault-finding? Should I try replacing the 79L05? The only different components I used were the FQT7N10LTF instead of the FQT7N10 which I couldn't find. Thanks, Regards, Marty.

[Math]

Love the name, books ordered..
This project looks great i cant wait to get started!
Well done George and thanks

[eclipse]

I have few boards for sale for Voodoo with shipping within the EU for 10E incl. shipping. Pay only if you get them for most forum members.
Boards are made in jlcpcb un-altered and in green color.
Free boards available for whoever bought defective board for TD3X from me as long as I have them in stock.

[surfdetector]

Hiya George,,,I'm having a little problem with my build. I am getting +5v at TP14,,but I'm only getting 0.720v at TP15. I bought 2 x programmed PICs from Andy (Silverdog) and though I totally trust his programming skills I tried both PICs and still don't get the correct voltage at TP15. I re-programmed one of the PICS with the HEX you posted and still not getting the correct voltage at TP15. I have checked and double checked all the components I installed for correct placement and values,,I've checked for solder bridges and dry joints and I've totally cleaned my PCB. Could you tell me what I could try next please in the fault-finding? Should I try replacing the 79L05? The only different components I used were the FQT7N10LTF instead of the FQT7N10 which I couldn't find. Thanks, Regards, Marty.

Marty are you getting the synch signal to the LT1054 from the PIC? I show it in my 2nd Youtube video.