Is it a kit?  It looks like it comes built!  Anyways that thing looks like it is very acurate.  Bruce's TPU would need 3 of these though...Is this what you will use on your TPU replication?

Yes I think you can get the DDS module as a kit, bottom of this page:
http://www.pongrance.com/dds.html

The beauty of these DDS kits is that they are very accurate, but even better they can be phase locked by tying the crystal clocks together.

I think you only need two accurate signal sources; I thought Bruce is saying you need 3 frequencies but only two of these are defined, these are 115kHz and 222kHz, then these two intermodulated frequencies when mixed with a third freq. (any freq depending on collector loop size) they will produce duplicate large constructive interference (kicks?).

p.s.
For a cheap genny, you can get purer freq by using opamps instead of 555 squares with smoothing filters, the cost would be similar and the parts count would be similar, this doc shows you how to build opamp sin oscillators all the way up to quadrature (4 phase):

http://www.ti.com/sc/docs/apps/msp/journal/aug2000/aug_07.pdf

Yucca.

edit:
If I replicate ala bruces instructions then I would initially using what I have, not perfect because the frequency output is not very stable in terms of radio quality.

But I want to get one or two of those DDS kits anyway, boxing them up with OP amped outputs would make a really nice bit of kit for the lab and would probably sell for more on ebay than the build cost.

That's some great info Yucca, thank you so much.  Those DDS don't need to be coded do they?  It looks like you adjust them with a pot!

P.S. What would you use for the 3rd signal source?

Hi Sptrue,

The DDS kits come with precoded microcontroller chip as part of the kit, if you blow it he will sell you another chip at a reasonable price. They are adjusted with an optical shaft encoder, a transparent disk with radial black sectors which a LED shines through and 2 photodiodes looks from the other side, as you turn pulses are generated which the micro acts upon, they dont wear out.

For the third signal source in the TPU scheme as far as Bruce sees it, you need to tune a loop antenna (inner collector) to some frequency using a cap and a smaller trimmer cap for tweaking, so you don't need a third source, the third frequency is a passive component (the LC tank of the inner collector unit). When the 3 freqs are working correctly then theoretically you can draw power from the DC biased outer collector and the more power you draw the more reinforcement, perfect tuning would result in runaway regardless of draw and failure of some part. I think adaptive tuning would be the answer for optimal performance, a microcontroller could achieve this by switching an 8bit power2 trimmer capacitance bank over the inner collector.

I so hope  Bruces ideas are the good stuff, even if they aren't I totally respect him for pushing the thought envelope. His excel spreadsheat does look very interesting, at the moment I can't quite comprehend the ramifications, but something in me says it is worth checking out, I have dreamed about it for several nights, my brain trying to undestand.

P.S. to all:
Don't worry, I will still be keeping experimenting with Smiths ideas. It's a whole new realm to me. When working with HV RF you can't just hook your dandy instruments up to it. A neon bulb is a mans best friend in this realm. It's an exotic area and one that is quite new to me, I'm enjoying it, spent over 3 hours last night with coils, grounding combos and neon sniffers, lots to learn here!

Hi Yucca
Wow that is a real pro build.

I am very pleased with the LCR meter it was £143 but a bit cheaper than the other one which was about £700 for a slightly better spec.

Anyone interested here's the meter ebay link, i will never need to worry about accurate LCR values again.

I have already played a little with a AD9835 and build 2 modules that plug into a cpu board.
Maybe my next controller will need 3 of these if i decide to go down Bruces path.

Here's a video of my last controller which i built to study the phase delaye bifilar coil experiment of Spherics and hence used to study the kick.

http://rapidshare.com/files/281469262/SPH100Controller.asf

I used a 8mhz 18F1320 Pic 100% machine language, and the maths to display the freq using an LTC6903 chip for the signal gen chip was quiet a challenge i ended up writing my own fast maths routines upto 12 decimal points using BCD as the floating point routines available were way too slow.

Peter

Hi Peter, Thanks.

Yes, fast maths in micros without floating pint processer is an art. I've found that using 16 bits and then right shifting 8 bits gives good speed and resolution (8 bits for integer and 8 bits for fraction) its sufficient for most apps.

So do you think that bruces ideas will need 3 accurate freq sources? From what I read it is two generated freqs and 1 passive freq that interacts with them, so only 2 active sig sources needed?

Downloading your vid link now...

i know what you mean about soldering those microscopic chips LOL the LTC6903 legs were barley visible and thinner than a hair LOL.
One trick i learned was you can blob solder all legs together then remove with solder wick to leave a well soldered chip.

At first i did not even know if i could get the res on the photo board and art work, but managed to perfect it ok.

Hi Yucca
To be honest i don't really know yet, i am going to let the dust settle and stay with Don's stuff for a while, the thing i don't understand, has he got it working or is this another unproven theory, he talks like he has built it, but has he.

I guess a 3 chan would be future proof 
Peter

Yep Peter, 3 Channel would be real nice! Perhaps we should set up a builders thread for it, I'm sure there's a few folk who would like such a piece of kit at an affordable price. Every TPUhead would drool over such a box.

I've watched all of those vids with Don. If I had been in the audience when he said "does anyone want to touch the wire to prove me wrong" I would have leapt up and grasped the wire between my tongue wetted thumb and forefinger! A small part of me wonders about the intent of Don, I think he's a great character but sometimes (when watching the vids) I sense a mischeaviousnes in him that makes me wonder about his truthfulness, but then perhaps it's just the excentricity that comes with genius?

The way I'm thinking at the moment is I will build up a repertoire of tools and components because the more the merrier and the more chance of seeing something special. RF systems are a new realm for me and this subject of Dons devices is throwing me in at the deep end which is good.

Yucca.

Peter,

Just watched your vid, QUALITY squared! Industrial grade GUI, 2nd menu level to select inc size is very nice, you must have got a buzz from producing it! I especially like your fast scrolling characters in menu transitions.

Like me you must find a certain elegance to a jogwheel controller with integrated push switch, with one human interface point the system is fully controlled, 3bit poetry.

I got 10 mechanical jogwheels with switch from china for peanuts, they're good but after a few hours of operation they start to get very noisy, I've written debouncing and smoothing algorithms into my code to compensate but the noise becomes too much after a while and I have to strip them down, clean with isopropyl and reassemble. I'd love to get some optical encoders but I can't find a decent (cheap) source.

Yucca

P.S.
I'm ispired to make a vid demoing my square gen, maybe I will.

Nice tip Peter, Thanks! so you can allow solder to flood across pins and then use resined wick to clear the spaces. I wouldn't have thought of that but it makes perfect sense.

Keeping them seperate was a challenge to me, I used 12AWG copper (end filed to bevel) wrapped around my iron tip and I had to have a nip or two of whisky to remove all micro tremors lol. I think I'll try the wick method next time.

Yucca.

LOL Yucca, just holding the chip in place and aligned can be challenging, i wish i had some of that glue they use in smd component placement.
In my case i needed the whiskey after wards, as it sounds easy to use the solder wick but you can suck too much up sometimes and end up with a dry joint that is not easy to see.