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Author Topic: Magnetic Resonance Devices based on Don Smith Concepts  (Read 453327 times)

Peterae

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #270 on: September 18, 2009, 02:35:11 PM »
I wonder which SM, there seems to be at least 3 so far LOL

If the pictures are indeed SM approved i doubt he has it right then, as i am sure that SM is not in a position to indicate how to build a worker otherwise he would have already posted the info himself.

stprue

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #271 on: September 19, 2009, 06:05:34 PM »
@ Peterae/Yucca

How are you're tests coming along?  Any new news to tell us?

Peterae

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #272 on: September 19, 2009, 06:38:02 PM »
Hi stprue

I am not much further ahead yet, i have been waiting on bit's and pieces.
but i have now sourced 5 Spark arrestors and they have arrived.
I have all my diodes and a bunch of HV caps including a couple of door knobs.
I have HV wire for my primary but have had trouble working out where to get 2 inch pipe to wind my primary on, i tried the local DIY store but they dont have any here in the UK, although i do have my eye on the Mrs Plastic Vitamin bottle LOL which is about 2 inch diameter.
I hope to build the primary and check the inductance out with my new meter and see what Don was aiming for with the 0.2uF caps and see how this compares with my secondary theoretical freq.

Peter

Peterae

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #273 on: September 19, 2009, 09:53:45 PM »
Anyone having trouble finding Spark Arrestors they are called Gas discharge tubes or GDT

Farnell do a whole bunch of different voltages

http://uk.farnell.com/jsp/search/results.jsp?N=0&Ntk=gensearch_001&Ntt=gast+tube&Ntx=&suggestions=false&searchTerm=gast+tube&_requestid=1275575&isGoback=false&isRedirect=false

Peter

forest

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #274 on: September 19, 2009, 11:12:40 PM »
Anyone having trouble finding Spark Arrestors they are called Gas discharge tubes or GDT

Farnell do a whole bunch of different voltages

http://uk.farnell.com/jsp/search/results.jsp?N=0&Ntk=gensearch_001&Ntt=gast+tube&Ntx=&suggestions=false&searchTerm=gast+tube&_requestid=1275575&isGoback=false&isRedirect=false

Peter

Great find!

However I don't see any for 4kV. Is there any GDT for such huge breakdown voltage ?

xee2

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #275 on: September 19, 2009, 11:21:55 PM »
Anyone having trouble finding Spark Arrestors they are called Gas discharge tubes or GDT

Farnell do a whole bunch of different voltages

http://uk.farnell.com/jsp/search/results.jsp?N=0&Ntk=gensearch_001&Ntt=gast+tube&Ntx=&suggestions=false&searchTerm=gast+tube&_requestid=1275575&isGoback=false&isRedirect=false

Peter

In the US, Newark Electronics has a good selection also.


Yucca

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #276 on: September 20, 2009, 02:08:34 AM »
@ Peterae/Yucca

How are you're tests coming along?  Any new news to tell us?

Still working with the 0.25 wave single secondary rig, I've seen some pronounced behaviour with regard to wiring configs:

When I connect the -ve side of the HV supply to the base of the secondary I see marked efficiency increase.

Further: when I then ground (to house radiator plumbing)  to the positive node of the FWBR another marked increase is seen.

Also I can load the system up with neons on sniffer coils, I tried 5, 1 above, 4 around and they all light brilliantly. As I add coils the existing coils do not diminish in brightness.

When placing a pickup bundle coil at the side it works strongest when vertically level with the primary.

My output gap and cap is the same spec as the input cap and gap so I think fire frequency gives me a fair representation of Pin/Pout ratio. I'm guessing I'm getting around 40% at the moment on output gap. BUT this does not diminish when I load the system further with neoned sniffer coils.

@All, (a little off topic),
I'm still thinking of building a 3 channel rock solid sin source with preamps up to 30MHz, I think the easiest way to go is make modular SMT boards, SMT seems cheap on components as Peter said plus researching I find that a good groundplaned SMT board gives the best HF performance with least stray capacitance.

The board would contain the DDS chip with crystal, elliptic filters and maybe HF opamp stage, a small disconnectable coax lead carries the signal to the users output port or maybe to an amplifier stage if they want to build one.

Boards can be simply stacked to add channels, 1 channel ... all the way up to four.

All channels controlled by a shared microcontroller and screen.

micro gives flexible software so multidimensional scanning could be programmed, the micro could also have an exposed (buffered) ADC pin for feedback, this way the system can be left scanning for days searching for maximal signal into ADC and the possibility of logging data back to the PC via USB for deeper analysis.

I guestimate a minimal bare bones 3chan up to 30MHz system would cost around $300 to make, but the pureness of freq could only be found in lab equipment costing a few grand new.

I just splashed out on a nice chinese shaft encoder which I plan to control the thing with:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320420562507#ht_2561wt_1167

Peterae

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #277 on: September 20, 2009, 01:10:52 PM »
@forest
I would imagine that a number of these could be placed in series to increase the gap voltage, although i have never tried this.

@Yucca
Great work thanks for sharing.

I like the idea of the Sig gen, spec sounds great, Wow that is some control encoder.


Peter

stprue

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #278 on: September 20, 2009, 03:06:06 PM »
Hi stprue

I am not much further ahead yet, i have been waiting on bit's and pieces.
but i have now sourced 5 Spark arrestors and they have arrived.
I have all my diodes and a bunch of HV caps including a couple of door knobs.
I have HV wire for my primary but have had trouble working out where to get 2 inch pipe to wind my primary on, i tried the local DIY store but they dont have any here in the UK, although i do have my eye on the Mrs Plastic Vitamin bottle LOL which is about 2 inch diameter.
I hope to build the primary and check the inductance out with my new meter and see what Don was aiming for with the 0.2uF caps and see how this compares with my secondary theoretical freq.

Peter

Well that sounds like your making lots of headway!  I found 2inch dia. PVC plumbers piping at a local hardware store.

stprue

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #279 on: September 20, 2009, 03:20:04 PM »
Still working with the 0.25 wave single secondary rig, I've seen some pronounced behaviour with regard to wiring configs:

When I connect the -ve side of the HV supply to the base of the secondary I see marked efficiency increase.

Further: when I then ground (to house radiator plumbing)  to the positive node of the FWBR another marked increase is seen.

Also I can load the system up with neons on sniffer coils, I tried 5, 1 above, 4 around and they all light brilliantly. As I add coils the existing coils do not diminish in brightness.

When placing a pickup bundle coil at the side it works strongest when vertically level with the primary.

My output gap and cap is the same spec as the input cap and gap so I think fire frequency gives me a fair representation of Pin/Pout ratio. I'm guessing I'm getting around 40% at the moment on output gap. BUT this does not diminish when I load the system further with neoned sniffer coils.

@All, (a little off topic),
I'm still thinking of building a 3 channel rock solid sin source with preamps up to 30MHz, I think the easiest way to go is make modular SMT boards, SMT seems cheap on components as Peter said plus researching I find that a good groundplaned SMT board gives the best HF performance with least stray capacitance.

The board would contain the DDS chip with crystal, elliptic filters and maybe HF opamp stage, a small disconnectable coax lead carries the signal to the users output port or maybe to an amplifier stage if they want to build one.

Boards can be simply stacked to add channels, 1 channel ... all the way up to four.

All channels controlled by a shared microcontroller and screen.

micro gives flexible software so multidimensional scanning could be programmed, the micro could also have an exposed (buffered) ADC pin for feedback, this way the system can be left scanning for days searching for maximal signal into ADC and the possibility of logging data back to the PC via USB for deeper analysis.

I guestimate a minimal bare bones 3chan up to 30MHz system would cost around $300 to make, but the pureness of freq could only be found in lab equipment costing a few grand new.

I just splashed out on a nice chinese shaft encoder which I plan to control the thing with:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320420562507#ht_2561wt_1167

That's interesting Yucca, I have seen similar increases in performance when grounding as well with my little hairpin.  Your freq. board idea sounds fantastic, I can't waite to see it.  I will probably build a simpler version using the links you showed me.  I was thinking 3 freq.  but I'll waite to see what Bruce shows us.

Yucca

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #280 on: September 20, 2009, 03:54:37 PM »
That's interesting Yucca, I have seen similar increases in performance when grounding as well with my little hairpin.  Your freq. board idea sounds fantastic, I can't waite to see it.  I will probably build a simpler version using the links you showed me.  I was thinking 3 freq.  but I'll waite to see what Bruce shows us.

Hi Sptrue, Yes, I too will wait on bruces revelations before proceeding with 3 chan. But I'll definitely build a 1 chan device to start with, last night I found these cool little breakout boards for AD9835 DDS chip, already soldered with split groundplanes and even an SMA connector built right in. With this I can make a 1chan for less than $70 including backlit screen and micro board. Then can extend by just buying more DDS modules, so a 3 chan for less than $150. The beauty of the module is that the TSSOP chip is ready soldered and also because it is a well designed board it is stable up to 25MHz. If you're interested then hold out on purchasing the other kit because I could provide you with micro code to give you a better spec unit thats easier to assemble (almost just all plugs together) at a cheaper price plus it will have more functionality, (programmable sweeps, TPU power out sampling, and USB comms to the PC). Watch this space lol.

Yucca.

slapper

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #281 on: September 20, 2009, 05:24:46 PM »
@Peterae

A couple of years back I was playing around spark gaps, injecting the spark into tpu control coils.

Although I managed to achieve a lower voltage gap (250 - 300 volts) it was not very stable and
my equipment still didn't like it much.

So I began to evaluate various lower voltage gas discharge tubes and found them to be quite slow
compared to a spark gap.

It looks like you are looking at the same GDT's and I am curious if you are experiencing similar results.

Take care.

nap
« Last Edit: September 21, 2009, 04:02:07 AM by slapper »

stprue

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #282 on: September 20, 2009, 05:43:03 PM »
Hi Sptrue, Yes, I too will wait on bruces revelations before proceeding with 3 chan. But I'll definitely build a 1 chan device to start with, last night I found these cool little breakout boards for AD9835 DDS chip, already soldered with split groundplanes and even an SMA connector built right in. With this I can make a 1chan for less than $70 including backlit screen and micro board. Then can extend by just buying more DDS modules, so a 3 chan for less than $150. The beauty of the module is that the TSSOP chip is ready soldered and also because it is a well designed board it is stable up to 25MHz. If you're interested then hold out on purchasing the other kit because I could provide you with micro code to give you a better spec unit thats easier to assemble (almost just all plugs together) at a cheaper price plus it will have more functionality, (programmable sweeps, TPU power out sampling, and USB comms to the PC). Watch this space lol.

Yucca.

That sounds great im not sure what micro code is!  Would it be compatible with a mac for loading?  Very exciting.

Peterae

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #283 on: September 21, 2009, 06:11:42 PM »
hi Slapper
I'm still in find bits and build mode, hopefully power up mode wont be too long away.

We have pictures of Dons device that use the GDT's so i am only trying to use what he used.

Peter

forest

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Re: Magnetic Resonance Devices based on Don Smith Concepts
« Reply #284 on: September 21, 2009, 09:06:35 PM »
What is the source of those images ? Are they valuable and real ones ?