Selfrunning cold electricity circuit from Dr.Stiffler

[Spokane1]

Dear DrZLowe7.

I received my order of 20 loops sticks quickly and just as you described. Thank you for the fast service. Let the experiment begin in ernest.

Since you  are the importer of these components do you happen to have any detailed information (data sheets or such) on just what these little black bars are made of? (or I should say what they are suppose to be made of). I don't care if they are composed of Barrium Ferrite or last years Peanut Butter. They seem to do some pretty interesting things as is and need to be investigated much closer.

You speak with the confidence of a person who has been in your business a while. As far as I can tell part of your customer base might be crystal radio hobbists. If you have a moment could you share with us your particular expericance with the performance, manufacture, and supply of the various antenna loop sticks that you have sold or experimented with over the years. Perhaps you might have some links to good information sources that explain just how these devices work in the first place - from a classical standpoint. How many different major variatons of this componenet are to be found in old salvaged transistor radios? Are they all basically all the same or do they fall into distinct classes or groups? I know there is a wide variation in aspect ratio, but does that have anything to do with the fundamental classical operation? Do the loop sticks in AM, FM, or ShortWave radios vary a lot? Is there a one size fits all?

I suppose, in the Crystal Radio Community, there are fundamental principles on how to improve the performance of these low power circuits that might not necessarly be based on pure classical electronic theory. Do you happen to know of any examples where the antenna loop sticks (like the ones you are selling) might have increased performance with no particular classical reason? Are there brands of loop sticks that are superior to others even though they have the same measurable parameters? (Like good Wine)

On eBay I notice there is a seller in Lithuania that is offering a number of 10mm x 200mm ferrite rods and some other configurations. Do do have any opinion on this product (or the seller if you have run across them)? They are suppose to be from a failed Russian Radio Factory. Shipping merchandise from that far away is bothersome to me. Anyway the seller claims that the frequency range is up to 1MHz for the small bars they carry. Any idea as to what the operating range is for your particular product? As it is, several experimenters are exciting your units with frequencies up to 28 MHz. This might imply that the non-classical process is the result of over stressing the componenets intended design frequency range, but this is pure speculation.

While we are on the subject, any ideas as to the specific composition of the Litz wire that makes the pick up coil? Like number of conductors and the actual bare diameter of each. I would like to calculate the effective surface area that is being employed here. Are there other high performance pickup coil configurations available from your supplier or some other 3rd party source? I can hardly see the bare wires let alone measure them.

In the Crystal Radio field, what is the purpose of the Litz wire? I notice in other, older loop sticks the wire appears to be a single conductor. What parameter improves with multiple conductors? Does the Q of the coil improve through reduced skin effect? Perhaps this modification is intended to extend the frequency range of the coil. If so do you have any idea what kind of improvement a Litz wire coil has over a single conductor coil. In a application such as this does the intened operation depend on the length of the coil wire or just its effective inductance? Is the coil specifically engineered to match the Ferrite bar? or can I take the Litz coil and slip it over a longer Ferrite bar and get similiar or better performance? Is it true that the size of the Ferrite bar increases with length and is actually limited by the case it is to be installed in, thus providing another engineering trade off between length and performance.

Since you already have an established import business and probably get catalogs from the OEM's in China (and other places) are there other configurations of  Ferrite loop sticks or Ferrite rods and bars that are available should a local market develop here? Or is this component on its way out (like the vaccum tube) in favor of newer technologies? Is there more than one supplier of this product. Can you get these components from other countries - I know they would be more expensive from other sources. Are these bars available in bulk with out the pickup coil?

Do you have enough experiance in the marketing of these components such that if I were to discover that a particular salvaged loop stick had a record breaking performance  that you could tell me from looking at it where, when, and by who it was made? (I know this is a tall order but it might be a skill very much in demand in the near future)

Thank you for your factual analysis and any replies that you might have time to share with us concerning this multitude of questions.

Spokane1

[hartiberlin]

@MRAMOS,
it is all on his page:

http://www.drstiffler.com/ce4.asp

Have a look there at

Fig: SP0x
and

Fig: SP0y


Good luck.

Regards, Stefan.

[hartiberlin]

L2 is the litz wire coil from the AM core
and L3 is the hand wound about 10 turn coil around it.
He used 2 coils in the circuit diagram for L2, cause it justhad more turns,
so to make it clear which one is the bigger turn Litz wire coil = L2

L1 is a 2.2 uH coil.
You can buy one in an electronic shop.
I bought one and mine looks like a resistor,
but Dr. Stiffler had an aircore coil for it.
Look at the real pictures in his page.

[MeggerMan]

Hi Stefan,

L2 is the litz wire coil from the AM core
and L3 is the hand wound about 10 turn coil around it.
He used 2 coils in the circuit diagram for L2, cause it justhad more turns,
so to make it clear which one is the bigger turn Litz wire coil = L2

Thanks for the info on the L2 showing as two coils, this was really confusing me - now I know its one coil.
Have you got an LCR meter?
Using this you could wind the L1 air core coil by hand and add/remove turns to get 2.2uH.
If we could work out using some standard plastic pieces for a former, I could wind it and tell you the number of turns using my LCR meter so that you could copy it.
Maybe a couple of discs of plastic, nylon bolt, nylon washers?

Regards
Rob

[DrZLowe7]

Stefan
I received a message from stating that the winding on L1 is important. So I looked at the schematic again. The Transistor M1 switches on and off the power pulse is Negative and  due to transformer action its power is directed in the Positive direction. Same as the diodes are wired. As stated earlier placing the open end of L3 may make this less important.

I was doing good to get the information I did on the coils. As far as I know it is in way special.
As far as other makes of ferrite bars sold I can not speculate on them. As they are made to perform best at certain frequencies.
The Litz wire I do not know gage ether however do a Goggle search will direct to sites that specifies number of wires diameters.
There is a theory that electrons only flow on the outer surface of a wire so the more the wires the better. I do not know of any positive proof however but there may be so deluge the site with posts about wire.
The Litz wire is covered with cotton making the spacing between turns greater thus reducing the capacitance and increasing Q value. I think if you had a 1 hair diameter wire and wind it to hairs distance apart it will work the same. Some swear by Litz and other say it makes no difference. I do not care they both work.
Toroid  coils have the best efficiency ratings that I know of that are readily available with many different core materials and sizes. However they are very difficult to wind.
I can think of no tricks basically like  Stiffler has done a low turn secondary and many turn primary on the Tank circuit. Voltage is everything in crystal sets as they have almost no load.
The company that makes my coils makes chokes and such. They make the AM coils special order for me. This is not a item they sell over the counter.

@MRAMOS,

It is not time to leave the 1970?s but return to under stand  function of these devices.
Every 20 years or so things come around again and each generation thinks it is new Fashions, Songs, and Electrical devices.
Let see if we can see what is going on here function wise. Ground is not always totally neutral or 0 potential. Try this if you have digital volt meter , with the set to around 20 volts AC scale hold one probe with your fingers and put the other on something you know is grounded. If you are not sure of grounding put the probe in the ground hole of an outlet socket. I get around 1.8 volts output. Checking a 12ft antenna I have strung about 6ft high I get .6 volts. A volt meter reduces the actual voltage output to .707 level so my 1.8V = 2.545 actual volts and .6V becomes .848 volts. Now run this into a step up transformer L2 and you get maybe hundreds of volts out. Remember we are dealing with RF here so placing a pan under the circuit dose not mystify its operation but helps explain it.  For one a Faraday shield should completely cover the circuit with no active wire leaving it unshielded . Leaving the top open serves no purpose as a shield.
Because he is using a ProtoBoard here there is a capacitance between every connection to ground no matter how small so every LED has a source to the back plane of the board. This is a path for RF to flow. Next placing it a pan also provides a capacitive connection to the pan another path for RF. So the back plane and pan only gives a loading source for the RF.
Now most grounding works by canceling out common noise like you read on your volt meter not because its totally neutral but provides an opposite charge in relation to your input as far as noise works. For the circuit to unexplainable the pan needs to be grounded at the coil side next the wire used for input needs to be shielded again at the coil end to ground and the base of ProtoBoard grounded also.
Most oscilloscopes with not pick up this noise as they are grounded again the ground canceling the noise. If any one wants to try take a cheap two prong extension cord and remove the area that prevents the cord from your oscilloscope  from connecting. Power up your scope place one hand on ground and probe any thing you can find. Next take 3 ft or so of aluminum foil and put one probe on it the other to your noise source. You will be amassed how much energy surrounds us.
For this to work Location is every thing the more active RF surrounding you the better chance. Because we are using transformers here their has to be AC from somewhere for it to work. This will not work in the middle of the rain forest with just a grounding rod in ground. This acts similar to standing under a high voltage power line lighting a florescent bulb but no need to step up voltage. Remember electric potential will flow in a single wire.
Again I am no criticizing his results only explaining how it functions as he said no one could answer this on his site. The only thing I can not explain is over 100ma drive.
I thinking of maybe starting a posting of how things function not perform however,
I also do not think L2 2.2uh is absolutely necessary.