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Zero Voltage Transmission (ZVT)


jasong

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Bad for White's, good for First Texas. I would love to see First Texas introduce something that would rock the prospecting world. Minelab could use some stiff competition.

To put it in perspective however Minelab could dust off the old SD2200v2 and release it again and have an entry level PI as good or better than what the competition offers. Instead of others catching up Minelab seems to be consolidating its technological lead.

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When I watched the introductory video, there were two spots were they implied that the GPZ is not a PI.

At the 51/2 or so minute mark the moderator says in highly mineralized ground the GPZ is much better than a PI.

I'm like you Steve, my eyes glaze over when I read the technical stuff but it sounds like this is new tech or a hybrid of some sort.

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Jasong,

 

FYI, the super DD coil was originally called the DOD coil when proposed by a guy in 2011 who went by the handle mikebg.  A pic of the coil in jpeg can be seen on the geotech1 forum.  Here is a link to it.

 

http://www.geotech1.com/forums/showthread.php?18469-Hammerhead-modded-vs-sd2000-series&highlight=mikebg+dod+coil 

 

Just drop down to mikebg's post and click on the DOD jpg pic.

 

Reg

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Thanks for the link Reg, I'll have to register there when I get off my phone, forgot my login.

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Jason,

 

Here is the pic mikebg posted in 2011.  This idea can be traced back to 2008 when mikebg posted something almost identical.

 

Depending upon the polarity of the to receive windings, they could be both ground and noise canceling. 

 

On level ground, this could allow the gain to be increased dramatically with the limit almost dependent upon internal noise.

 

Reg

post-307-0-39793700-1425061609_thumb.jpg

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Changing polarity on a receive winding is simple.  Lift the receive winding up and flip it over.  So, if you look at the pic above, then lift the top blue winding up and simply flip the receive winding so the right side of the winding is now on the left side and visa versa.  We could call this a half twist also.  The result is the top of the winding becomes the bottom, but fits the same. 

 

On a conventional DD coil, you could make a coil with inverted signals.  This works on some PI's but not all.  The TDI may not work or work right with this coil. 

 

Reg

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Each receiver antenna output feeds into a SUM/DIFFERENCE power combiner. If the two receiver antenna output signals are in phase, then the two signals are summed together for a 3 db gain out of the power combiner SUM port. However---the ground noise is also summed. If the two antenna output signals are 180 deg out of phase, then the power combiner DIFFERERNCE output port will yield a 3 db signal gain, but--- the two receiver antenna output ground noise signals will be canceled leaving only a 3 db signal gain. In other words, the ground noise signal is absent at the power combiner DIFFoutput port. Flipping the receiver antenna coils or connection wires does nothing to change this. The polarity of the received signal wave or field determines the receiver instantaneous antenna polarity regardless of antenna configuration or orientation.

 

 Installing a 180 deg signal delay line between one antenna output and one power combiner input port will yield a 3 db signal gain with about 20 db ground noise suppression out of the power combiner DIFF port. This is what you want.

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Hotrock,

 

"Flipping the receiver antenna coils or connection wires does nothing to change this. The polarity of the received signal wave or field determines the receiver instantaneous antenna polarity regardless of antenna configuration or orientation."

 

OH!!! Really?????

 

How do you reverse the phase of a winding? 

 

You really should build one and try it before making such statements.

 

BTW, I have built dozens of DD coils and used the simple technique of flipping the windings when the polarity is wrong.  Worked every time.

 

Reg

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  Reversing the signal phase of a receiver antenna output sign signal by reversing the Hi/Low antenna connections can not change the polarity of the induced wave or field on the antenna element. If the antenna element is the transmitting antenna coil then reversing the feed leads will momentarily reverse the radiated wave polarity. Certain kinds of receivers can detect this polarity interruption and use it as a timing marker.

 

 You are confusing reception post antenna signal polarity with induced wave antenna polarity. You are getting antenna wave or field polarity mixed up with antenna output signal polarity. There is a difference. I think we are talking semantics, which may be confusing when different terms are loosely used in a broad context.

 

 If physically flipping the receiver antennas or connections affect the detector's performance, then it is the post antenna signal processing configuration that is affected, not the antenna configuration. In other words, the same results could be achieved with a different post antenna signal processing circuit configuration, which means that it is not just an antenna gimmick.

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