Re: those folks at MIT (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sat, 23 Jun 2007 18:19:38 -0700
From: Ed Phillips <evp@xxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: those folks at MIT (fwd)

Tesla list wrote:

>---------- Forwarded message ----------
>Date: Sat, 23 Jun 2007 11:08:05 -0300
>From: Antonio Carlos M. de Queiroz <acmdq@xxxxxxxxxx>
>To: Tesla list <tesla@xxxxxxxxxx>
>Subject: Re: those folks at MIT (fwd)
>
>Tesla list wrote:
>  
>
>>---------- Forwarded message ----------
>>Date: Tue, 19 Jun 2007 17:05:30 -0700
>>From: Ed Phillips <evp@xxxxxxxxxxx>
>>To: Tesla list <tesla@xxxxxxxxxx>
>>Subject: Re: those folks at MIT (fwd)
>>
>>    Thank you for sending the paper.  Have you read the original article 
>>in ScienceExpress which got this discussion started?  I would have 
>>expected a comment from you if you had and have been wanting to see it.
>>
>>  
>>    
>>
>I have read the papers. Not great novelty, just a quantitative 
>evaluation of what can be achieved.
>Some time ago I was making some experiments with pulse radio, with a 
>setup that was like two
>Tesla coils at some distance, connected to antennas. Similar to the old 
>system for spark radio
>using tuned circuits. At one of the coils the primary capacitor was in 
>series with a low-impedance
>signal generator producing a square wave.
>At the other end I was observing the voltage over the primary capacitor.
>Each transition of the (low impedance) square wave was producing a an 
>energy-transfer transient
>similar to what occurs in a Tesla coil.
>I don't have the results here, but I remember that the attenuation was 
>not large. The system was
>operating at 10 MHz, and the distance between transmitter and receiver 
>was about 2 meters, with
>1 m vertical antennas. The coils were cylindrical, about 15 cm high and 
>10 cm wide, with internal
>primary coil. Just a few tens of turns.
>I remember that I commented that no amplifier was required at the receiver.
>I have to comment that the amount of wire used was much greater than 
>what would be required
>to connect the transmitter directly to the receiver without measurable 
>attenuation, hehe...
>
>Antonio Carlos M. de Queiros
>  
>
Antonio:

    Thanks for your comments.  Seems to me you mentioned those 
experiments here on pupman and steered us to some photographs you had 
taken.  As for this paper you'll note that the authors didn't cite any 
papers on RESONANT coupling, only on inductive coupling at power line 
frequencies; the Tesla patent covered top load construction as I recall 
and they completely missed his "world power system" patents.  Careless 
research at best!!!  .  I think most of us believe that they think 
they'd discovered for the first time that "self resonant circuits" 
couple more tightly and that detuning reduces the coupling!!!  Lodge 
demonstrated the latter in 1889 and Tesla certainly had many public and 
private (Colorado Springs) demonstrations by the turn of  the 20th 
century.  Essentially all spark transmitters used resonant coupling of 
course.

Ed