Peter, whatever happened with Eric P. Dollard?

[Sputins]

599

Notes on the Crystal Set

When measuring the velocity difference between underground and our ground, the two seperate receivers can be brought into phase unison by the use of a test oscillator. Both receivers must have a primary tank circuit, here you can place your measurement equipment.

The detected AM output, audio frequency, signal is immune to receiver phase shift. This is a property of A.M. detection. Use the audio to measure propagation delay.

Wind all coils in the same direction, this is a must! Brass is a very good primary material, good depth of penetration at broadcast frequencies. Wires and clip lead interconnection are the "Road to Absolute Defeat." Coils and Condensers must be merged into each other in broad surfaces. Stacked metal plates on insulators makes good condensers. Transmitter air condensers are good, vacuum condensers are the best. A number of small condensers are better than one big one, less stray inductance. Stray inductance is fatal to success! For smaller units silver mica condensers are the only way, use no others. Paralell them on a low inductance bus.

Do not get sidetracked, experimental and auxilliary coils as well as patent diagrams will get you stuck in the sand forever. The finished Colorado unit dimensions are all in the notebook. It is all there, look at it, not the diversions, and remember everything you thought was Tesla is the exact opposite. It is there; one or two turn primary; a 20% height/width secondary; and a 100% height/width extra coil, all there, wire size, turns, all there, can you find it? It then can be scaled to any frequency and any KVAR capacity within wavelength conditions.

As your unit gets perfected the signal gets stronger and stronger, then diodes start burning out. We then are reaching the engineering objective, that is to light a number 327 pilot lamp. Not much power but too bright for Einstein.

Thank you Eric,

599 - Loud and clear on the engineering details & tips provided!


Colorado unit dimensions:
(Taken from C.S. Notes* & Leland Anderson’s publication).

Primary coil: 51’ diameter Two turns – (further details to follow)**
Secondary coil: 51’ diameter 9’ high, 29 turns, heavy cable.
Extra coil: 8’3’’ diameter, 8’ in length, 100 turns No.6 wire.

*C.S.N. (page numbers to edit in here later).
**More reading required for correct answer on this, (Feel free to help and add an answer you E.F. mob)!

My Radio “receiver” is under consideration, parts acquisition & construction..

[t-rex]

Tesla Type Crystal Radio

The design of the Tesla Transformer starts with the secondary resonant coil. In its resonant mode it is a quadrapolar resonator. Two constants exist in the construction of this solenoidal resonator, one is that the height to length ratio must be 20%, the other is that the side by side spacing of the cylindrical conductor turns is 62% the diameter of the cylindrical conductor. The optimum number of turns is 20 on the secondary, with 2 on the primary. This gives the physical size of the coil for a given frequency. Increasing the number of turns reduces the size of the secondary coil in proportion to the increase in turns. Accordingly the conductor diameter also decreases as the copper is spread out over more windings. The ratio of secondary turns to primary turns must equal a constraint of 10 to 1. For a given number of turns the operating frequency becomes the sole independent variable in coil design.

The primary coil is the same diameter as the secondary coil. The ratio of conductor width to coil diameter is 18%. The sheet conductor is closely spiralled into two turns, for a secondary of twenty turns. For a conductor thickness as given by the maximum thickness vs frequency the volume of the primary metal must equal the volume of the secondary metal, based upon equal weights for primary and secondary metals. Brass can be 1.7 times thicker than copper, and bronze can be 2.8 times thicker than copper, for a given maximum thickness and frequency.

The primary condenser should be made of the same amount of metal as the primary coil. Their weights should be about the same. The connecting leads must be short and the same width as the primary conductor. Large, multiplate air condensers are good, so are metal sheets and glass.

The secondary capacitance is best a copper tubing ring around the outside of the H end of the coil. This ring must be open in one spot along its loop so as not to be a shorted turn. The end of the secondary wire connects to this capacity ring. Beer cans make the best elevated capacitors.

The finished transformer must operate on a directly connected ground plane. A large plywood table with aluminum foil glued on to it, this covered with a plastic or glass sheet is the minimum required ground plane. Obviously the aluminum plane must be solidly earthed with special attention to minimizing ground lead inductance. In order to light a lamp a more broadcast station style of ground plane is required, but for testing purposes the metallized plywood "ten by" sheet is just fine. Good luck and good crystal set DX ing.



73 DE N6KPH

[madhatter]

shouldn't the self capacitance and inductance be calculated to insure that the secondary coil does not resonate at a slower frequency from the primary and also to insure that LsCs = LpCp ? and from this then the resonance should be easier to maintain.

[Geometric_Algebra]

Crystal radio construction

Eric, thanks for the additional design information. The initial approach that I have taken with physical construction has centered around copper weight balancing of the coils, but designing around the resonant frequency makes the most sense now doesn't it? It's a bit of a chicken and egg problem, do I start with the materials available or do I start with the number crunching. I started somewhere in between and it's been a pretty fun learning process to iterate as the equations become more clear and the manufacturing skills improve.
Electrical measurements are still an issue to be dealt with.

Maybe a simple c-program to crunch the numbers as a design aid would be useful.

[madhatter]

Eric, thanks for the additional construction information. The initial approach that I have taken with physical construction has centered around copper weight balancing of the coils, but designing around the resonant frequency makes the most sense now doesn't it? It's a bit of a chicken and egg problem, do I start with the materials available or do I start with the number crunching. I started somewhere in between and it's been a pretty fun learning process to iterate as the equations become more clear and the construction skills improve.
Electrical measurements are still an issue to be dealt with.

Maybe a simple c-program to crunch the numbers as a design aid would be useful.

In order to get the weight you need to start with the frequency, from that it'll determine the wire length and then the weight based on wire gauge or in the case of the primary flat wire strip. capacitance and inductance will also cause a change in the number of turns based on wire gauge. it does seem a bit of push-pull but if one is pinned down then the rest follow.

Eric is right that all the needed calcs are in the notes, I personally have been fascinated by the calculations and how Tesla is utilizing them for design and implementation. I do enjoy his reference to and use of other equations as a secondary check against his calcs.

Too much inductance slows down the natural fq so capacitance needs to annul it, however if self capacitance is too high it will also slow the fq while increase the Q, If it's to small then it doesn't transmit the power and the fq will be to high. it's a balance act of just the right capacitance to annul the mutual inductance of the primary and secondary, hence utilization of the 'extra' coil for capacitance. along with all that resistance needs to be as negligible as possible. A balancing act for sure.

I have thought of a simple program to crunch the numbers as the equations are not that complex. difficulty though is that there are a fair number of variables and one needs to grasp how each impacts the other or the calculations will not work. it's not a simple flow diagram from A~B. still should be possible, I've written complex calcs for thermodynamic flow that had numerous variables.

No promises as I still want to spend more time crunching the numbers and seeing the ratios. Eric has posted a great start that will enable anyone to build an antenna that will work as described, all that's needed is the frequency and L and C calcs.

[Kokomoj0]

interesting.....

just from observation I would not expect a 2 turn primary to really couple in the same sense we normally think of a tank?

Again by observation, I get the impression the primary is to transfer a very fast impulse in a very broad band low q arrangement to the secondary by means of a magnetic pulse, not exactly sure how that would relate to the electric field transfer.

So it seems the 2 turn primary would function more so as an exciter and be sort of freq independent to the system because I presume it would have very low q and not really tunable as such.

It seems to me that the goal of the primary is ideally infinitely high current with infinitely short pulse width causing infinitely high spike impulses would best be achieved as Eric is saying with the use of flat strap and vacuum caps etc. The resonance of a 2 turn coil would be several orders above the fundamental of the secondary or the extra coils.

That said it would create a corresponding magnetic flux setting the secondary in motion which I believe is a 180 degree tank giving the joule ringer effect and a tendency to store and build up energy if you will.

Then the extra coil appears to be needed to get that open ended 1/4 wave length which will cause it to transfer with that vacuum cleaner effect that Eric was talking about.

If I understand what is going on here correctly, while everything is important, if the secondary is in fact a 180 degree coil that to me would be the most important coil to have properly tuned to prevent leakage then tune the extra to it.

So at first blush I would consider winding the secondary then put it in parallel with a non reactive load resistor and build 2 little z matched strip line swr meters, one for each coil lead and use those measurements to adjust for a perfect known 180 degrees, and that would also work to match the extra coil.

I have been busy to the extreme with barely enough time to read the posts, so I have not run any math, just what I gather from combining what has been said and my past antenna building experience.

If this turns out to be incorrect I will redact this to keep the thread clean.

[Sputins]

Seconadary Coil Calculation for 1395kcps

The design of the Tesla Transformer starts with the secondary resonant coil. In its resonant mode it is a quadrapolar resonator. Two constants exist in the construction of this solenoidal resonator, one is that the height to length ratio must be 20%, the other is that the side by side spacing of the cylindrical conductor turns is 62% the diameter of the cylindrical conductor. The optimum number of turns is 20 on the secondary, with 2 on the primary. This gives the physical size of the coil for a given frequency. Increasing the number of turns reduces the size of the secondary coil in proportion to the increase in turns. Accordingly the conductor diameter also decreases as the copper is spread out over more windings. The ratio of secondary turns to primary turns must equal a constraint of 10 to 1. For a given number of turns the operating frequency becomes the sole independent variable in coil design.

The primary coil is the same diameter as the secondary coil. The ratio of conductor width to coil diameter is 18%. The sheet conductor is closely spiralled into two turns, for a secondary of twenty turns. For a conductor thickness as given by the maximum thickness vs frequency the volume of the primary metal must equal the volume of the secondary metal, based upon equal weights for primary and secondary metals. Brass can be 1.7 times thicker than copper, and bronze can be 2.8 times thicker than copper, for a given maximum thickness and frequency.

The primary condenser should be made of the same amount of metal as the primary coil. Their weights should be about the same. The connecting leads must be short and the same width as the primary conductor. Large, multiplate air condensers are good, so are metal sheets and glass.

The secondary capacitance is best a copper tubing ring around the outside of the H end of the coil. This ring must be open in one spot along its loop so as not to be a shorted turn. The end of the secondary wire connects to this capacity ring. Beer cans make the best elevated capacitors.

The finished transformer must operate on a directly connected ground plane. A large plywood table with aluminum foil glued on to it, this covered with a plastic or glass sheet is the minimum required ground plane. Obviously the aluminum plane must be solidly earthed with special attention to minimizing ground lead inductance. In order to light a lamp a more broadcast station style of ground plane is required, but for testing purposes the metallized plywood "ten by" sheet is just fine. Good luck and good crystal set DX ing.



73 DE N6KPH

Calculated values for a Tesla Transformer Secondary Coil.

Calculated of from Eric’s GIVEN conditions.
(See Tesla Type Crystal Radio formulas above).

My Calculated values are based on an AM receiving frequency of 1395Kcps.

1. Total Length of Coiled Wire lo (for Frequency of 1395kcps)

lo = 34.244 Meters or lo = 3424.4 Centimeters.


2. Total Number of Turns GIVEN 20, Length of Each Turn:

l = 1.7122 Meters or 171.22 Centimeters.


3. Coil Height to Width Ratio GIVEN 20%:

W = 0.5449 Meters or 54.49 Centimeters

H = 0.10898 Meters or 10.898 Centimeters.

4. Side By Side Wire Spacing GIVEN 62% of Wire Diameter for 20 Turns, A Wire Diameter of:

d = 0.03322 Centimeters or d = 3.322 Millimeters.

5. Maximum Conductor Thickness is GIVEN by 10 / sqrt F:

Thickness of Copper = 0.008466 Centimeters or 0.084 Millimeters
Thickness of Brass = 0.1439 Millimeters.
Thickness of Bronze = 0.2370 Millimeters.


(6). Primary Coil Width GIVEN 18% Ratio to Coil Diameter:

Primary Coil Width = 9.808 Centimeters.

Primary Coil Length = Two turns of ~ 171.22 Centimeters
Primary Coil Length = ~ 342.44 Centimeters. Or 3.4244 Meters.

Please correct and or check me if my values are off, please compare them to yours figures.

I am yet to calculate weight of copper contained in primary to weight contained in Secondary, I will try on a per volume calculation next. I will also measure these by weight (per meter) on an accurate balance to help determine this. More later.. Of course for lower frequencies the coil's overall physical size becomes larger.

The important calculation factors here have been GIVEN from Eric, for which I must say thank you! - Too bright for Einstein.

[madhatter]

I'm currently only 1/4 of the way thru the Colorado spring notes. while the above posted construction details by Eric are useful there is still the matter of inductance and capacitance to be accounted for. I have also noted that Tesla's Eq for such vary from the current ones today. I would err to Tesla's Equations for such calculations over the commonly available ones on the net as the ones in the notes will derive a period of oscillation for various capacitance and mutual ratios in the circuit.

the period of oscillations need to be in harmony between the primary and secondary to give the best resonance.

As I said I'm only 1/4 the way into the notes, if any of this changes I'll correct my post, however I don't think it will as these points are a common thread in the notes and Tesla is so far only tweaking or tuning the accuracy of the setup, the equations are boiler plate in this regard.

[pnajafi]

What is Mr. Dollard's take on Mr. Meyl

Hi,
I am a noob and recently been trying to replicate this slowly. So far I have a manual by IEEE Steve Jackson which replicates an example based on Prof. Meyl's kit on one-wire transmission.

I heard that Mr. Dollard is not happy with Professor Meyl's way of doing it and find it difficult to reason why. Professor Meyl says the same things as achieving 1.5 times of the speed of light and he mentions the longitudinal waves, I guess his approach uses neutrinos or something to that effect to connect with particle theory.

Why is Mr. Dollard against some of Mr. Meyl's notes? In what areas?

I am really sorry if I have asked a similar question again and look forward to concrete reasons as to why and what ways exist to cope with the uncertainty around research. Like to know what to know from where.

[Nhopa]

Substitution

Hi all:
Reading the notes, the name of two items often come up , the "sensitive device" and the "mercury break" or "Thomas clockwork with wheel". The sensitive device looks very similar to a Reed switch, so the question is, can one use the Reed switch, inserted into a coil, in lieu of the sensitive device's glass tube with the two wires?
The question about the break is what kind of mechanical device, if any, can be used instead of the mercury break or the Thomas clockwork? Is there anything commercially available out there? If not, are there plans available to build one of these devices at home?
For use with lower voltages I have seen an electronic "break" circuit that employes a 555 IC timer. It was published in the Borderland Sciences 4th edition of the "The Lakhovsky Multiple Wave Oscillator Handbook", pages 45and 125. This circuit has a variable frequency range between 130-1,300 Cps.
I am currently getting the required components to build this circuit and if it works as advertised then I will publish it on this forum.

[t-rex]

Tesla Resonant Transformer

[madhatter]

Eric what about distributed capacitance on the secondary? the version and I'll call them that because I have no idea how accurate they are of the Colorado notes I have, have a final revision of the 2nd coil @ 15m dia, with 18 turns, 4 lower @ 1" spacing and the remainder of 2.625" for a total height of 42"

[madhatter]

Wire length, the eq l=c/w would be for a straight horizontal length. However in a coil the inductance and capacitance would change that as Tesla notes in the use of inductance and distributed capacitance equations to calculate the free resonance of the coil. The frequency of charge impressed into the primary was 1600Hz per the notes and the resonance was based on inductance and capacitance at that fq in the length of the primary, it was then calculated to have the length of the secondary match that resonant wavelength based again on the inductance and capacitance.

I have another question, in previous posts you mention the wavelengths of the primary,2nd and extra as:
Primary: 1/2
Secondary: 3/4
Extra: 1/4

The notes have these relations:
Primary: 1/4 or 1/2 depending on series of both turns
Secondary: Sep 4th 1/4
Extra: Sep 4th 1/16 ; Sep 19th 1/2 per diagram #4

[madhatter]

there seems to be an issue with the 'notes', apparently various translations are edited and most likely incorrect. does anyone have any idea as to which one is most accurate and where to procure them?

thanks,

My above posts are based on the notes I have by
ALEKSANDAR MARINCIC, D.Sc.
ASSOCIATE PROFEsSOR OF ELEClltICAL ENGINEERING aŁOGRAD UNIVERSITY
SCIENTIFIC ADVISER TO TtlE NlkOLA TESLA MUSeUM

note sure how accurate these are...

[skaght]

Quadripolar resonance equations

I don't understand the quadripolar resonance equations. The only practical value that I can see that would satisfy the equations are when L=C=M=K=1, which seems extremely limiting. I can't see how a tesla coil could satisfy this. It's been a while since I've done my college math courses, so if I'm missing something, please point it out.