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Hi Chris,
Tried your E-Mail but it was returned.
You seem to know what's going on. HELP!!
I am trying to build one of these deep seekers.
http://www.thunting.com/cgi-bin/geotech/pages/common/index.pl?page=metdet&file=/projects/deepseeker/index.dat
Know very little about pot core xformers. My total experience is winding one for a proton magnetometer in the early 70 s.
I've wound the xmit coil on a pot core I have.
Has 2597-A 9-9-69 in red on top of it and 57 in blue green on the bottom. Probably doesn't mean much without a mfgr.
Two piece shell, one section bobbin and the 6,35,165 turns, #30 almost fills the bobbin. Shell diameter is about 7/8". I jumble
wound 6 turns (tap) 35 turns (tap) then 165 turns.
My thought is that even if the pot core is not the exact one required shouldn't the transmitter still oscillate (just at a different frequency)??
The listed inductance at the Geotech site is 168 mH??? Does that seem right to you??
Maybe it is 168 uH. I have other questions (no answers).
On the first page 2nd column it says 20 kHz but on page 6, "How it Works" paragraph, it says it operates at 100kHz. With an inductance of 165 uH and capacitance of 450 pf resonance would be like
58 kHz. Which is close to what I have seen on my freq counter.
(CALCULATORS)
http://www3.telus.net/chemelec/Calculators/Calculators.htm
100n is 0.1 uF. 4n7 is 0.0047 uF. Did I get that right??
For the AC128 I subbed a NTE157.
What I think I should see on my scope is a burst of 20 or 100 kHz (in my case no telling what) at a frequency set by the timing of the variable resistor c2, c3, r1, r2, and the BE junction of Q1.
Does any of this make sense? I've built the xmitter twice now. No solder bridges open connections etc...
But It does not seem to work as I expected.
If this detector is as good as reported in the article I would like to have one as a companion to my Cesium Magnetometers.
Any help, suggestions etc. from anyone appreciated,
Don
Visit my web pages, Magnetometers, Lost Adams Diggings pictures,
THing etc.. Window to my world listed below.
Window to my web pages
Tried your E-Mail but it was returned.
You seem to know what's going on. HELP!!
I am trying to build one of these deep seekers.
http://www.thunting.com/cgi-bin/geotech/pages/common/index.pl?page=metdet&file=/projects/deepseeker/index.dat
Know very little about pot core xformers. My total experience is winding one for a proton magnetometer in the early 70 s.
I've wound the xmit coil on a pot core I have.
Has 2597-A 9-9-69 in red on top of it and 57 in blue green on the bottom. Probably doesn't mean much without a mfgr.
Two piece shell, one section bobbin and the 6,35,165 turns, #30 almost fills the bobbin. Shell diameter is about 7/8". I jumble
wound 6 turns (tap) 35 turns (tap) then 165 turns.
My thought is that even if the pot core is not the exact one required shouldn't the transmitter still oscillate (just at a different frequency)??
The listed inductance at the Geotech site is 168 mH??? Does that seem right to you??
Maybe it is 168 uH. I have other questions (no answers).
On the first page 2nd column it says 20 kHz but on page 6, "How it Works" paragraph, it says it operates at 100kHz. With an inductance of 165 uH and capacitance of 450 pf resonance would be like
58 kHz. Which is close to what I have seen on my freq counter.
(CALCULATORS)
http://www3.telus.net/chemelec/Calculators/Calculators.htm
100n is 0.1 uF. 4n7 is 0.0047 uF. Did I get that right??
For the AC128 I subbed a NTE157.
What I think I should see on my scope is a burst of 20 or 100 kHz (in my case no telling what) at a frequency set by the timing of the variable resistor c2, c3, r1, r2, and the BE junction of Q1.
Does any of this make sense? I've built the xmitter twice now. No solder bridges open connections etc...
But It does not seem to work as I expected.
If this detector is as good as reported in the article I would like to have one as a companion to my Cesium Magnetometers.
Any help, suggestions etc. from anyone appreciated,
Don
Visit my web pages, Magnetometers, Lost Adams Diggings pictures,
THing etc.. Window to my world listed below.
Window to my web pages
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