Coil question for Reg

[Frank-S]

Reg A pi mono coil has one winding,DD coil has 2 winding.
Lets say induction of mono coil is .300mh. the pi came with a mono coil
and some-one wonted to make a DD coil for that pi.is the RX .300 mh and
TX coil the same inductions,or is the RX less induction

 

[Frank-S]

Question for any-one that has made a DD coil for a PI detector.
the RX and TX coils do they usely have same induction.
Thanks,

 

[Reg]

Generally, the inductance of the RX is equal or greater than the TX on a DD for a PI. Some make the coils with 300 uh for the TX and 450 or so for the RX. When I made my first one, I used the same inductance for each winding. They worked, but later when I used a different inductance for the RX, they seemed to work better.

I haven't made a DD coil for a PI in years. If I were to make one now, I might use 275uh to 300 uh for the TX and maybe 425 for the RX. Since I would most likely be making one for an Eric Foster design, I would probably use 24 to 26 awg wire for the TX and much smaller for the RX, even down to 30awg kynar for the RX.

Reg

 

[6666]

Hi Reg
I've seen posts by Eric were sometimes he mentions he uses pvc covered multistrand wire in his coils, a bit tecky , but would you know if he favors tined multi strand , or plain copper ?, thanks.

 

[Reg]

Towards the end he was trying for 10 usec use, so he used stranded Teflon coated wire for his high powered GS 5. On some others he used Kynar or Teflon coated coated 30 awg for some of his low powered coils that were for detectors not as fast.

Getting a high powered 11" coil to work at a trie 10 usec is quite an art.

Reg

 

[6666]

Towards the end he was trying for 10 usec use, so he used stranded Teflon coated wire for his high powered GS 5. On some others he used Kynar or Teflon coated coated 30 awg for some of his low powered coils that were for detectors not as fast.

Getting a high powered 11" coil to work at a trie 10 usec is quite an art.

Reg

Thanks Reg, yes <10 usec is difficult.

 

[Davor]

6666, Eric specifically mentioned tined multistrand. Makes sense.

 

[Reg]

6666,

You are right, I didn't mention the wire used on the high powered unit was stranded. I believe he used 26 awg for the high powered coils.

Reg

 

[Frank-S]

Thanks Reg.
Frank

 

[6666]

Thanks Reg and Davor, then tinned 26awg it is, Eric used to publish some very educational information which was very usefull for experimenting.