US2376101A - Electrical energy transmission - Google Patents

Description

May 15, 1945. H. J. TY'zzER ELECTRICAL ENERGY TRANSMISSION Filed April l, 1942 mwa HGV/ARD J. TYZZR Patented May 15, 1945 UNITED STATES PATENT GFFICE 2,376,101 ELECTRICAL ENERGY TRANSMISSION Howard J. Tyzzer, Caldwell, N. J., assig'nor to Ferris Instrument Corporation, Boonton Township, N. J., a corporation of New Jersey Application April 1, 1942, Serial No. 437,109

(ci. iis- 44) Claims.

certing when the transmission involves electrical alternating current energies having in very large numbers frequencies of more than one hundred megacycles, the uses of which are becoming quite commonplace.

A particular object of my present invention is the one of making it possible to more accurately measure the amount of energy that remains after such transmission in cases of transmissions over a. wide range of frequencies without resorting to making adjustments at each frequency as the measuring progresses. For example, I have in mind accurately and yet speedily checking the response characteristics of radio devices built to be effectively responsive to radio signals of a wide range of frequencies in the neighborhood of and above one hundred megacycles with the aid of a so-called standard signal generator such as described by Malcolm Ferris in U. S. Patent 2,265,637 of December 9, 1941 It is the history of the art that when the said Ferris applied for his said patent in May, 1937, commercial radio transmission at frequencies in the neighborhood of one hundred megacycles did not exist, and I now find that the valuable contributions the said Ferris did mais@ to the art in the matter of the proper steps to take for dependable cable transmission of the energies of alternating currents at frequencies from ten megacycles upward are not sufllcient to meet in accuracy the present time requirements in the cases of devices calling for highly dependable results at great numbers of frequencies even far above one hundred megacycles.

I have discovered that the reason why the teachings of the said Ferris patent fail to provide for satisfactorily accurate transmissions at one hundred megacycles and above is that the radiations from his transmission means at such frequencies become too large to be ignored, and it is by the application thereto of my present invention that the resulting inaccuracies are satisfactorily overcome.

It is believed that my invention will be best understood by references to the figures of the accompanying drawing in which Figs. l and 2 are but slight'modications of each other, and in which like reference numerals and letters refer to parts having like functions.

The difference between Figs. l and 2 is that the former shows in elements l and 3 a coaxial cable as transmission means and the latter two parallel conductors l and 3 as transmission means. In both cases, the sheaths indicated by the even numbers 2, 4, etc. are of insulating material or materials, and the sheaths indicated by the odd numbers 3, 5, etc. are of conducting material or materials; that is, in both cases there are alternate sheaths of insulating and conducting material or materials, and while in both cases the sheaths are shown as cut short or pushed back for illustration purposes, in actual use they are all of the same length.

For convenience, these sheathed transmission means should be quite exible so as to permit of being readily moved for attachment to differently located devices being checked, and I have found that a braided conducting sheathcovered by a braided insulating covering, such as mercerized cotton, is quite effective; however, it is obvious that any combination of conducting and nonconducting sheaths is susceptible of being successfully employed. As to length of the transmission means in connection with standard signal generator work at frequencies of one hundred megacycles and above, although the severity of the problem of maintaining accuracy increases with increase of length of the transmission means, practical Working requirements call for a length of about three feet.

As to operation, referring to Fig. l, C indicates an ordinary metallic cabinet containing as indicated, variable in frequency, source of electrical alternating current marked AC, usually of socalled vacuum tube oscillator form (showing the details of whichv is not essential to a description of my present invention), the alternating current of which may be modulated at preferably one suitable to the average bearing of potential operators audio frequency by an indicated modulator M, and used to develop an alternating potential in a suitable impedance means such as indicated resistance Rl.. By connecting conductive elements l and 3 of the transmission means across a chosen portion of resistance Rl, such as the portion indicated by R2. a chosen amount of alternating current is caused to flow through the transmission means to and through resistance R, and there develop an alternating potential across terminals Tl and T2V for application to any device to be tested and/or checked as to its responsive characteristics. As taught by the above mentioned Ferris patent. I make the resistance value at each of the two ends oi' the transmission means substantially equal to the characteristic surge impedance of the transmission means per se.

I have found that by fully and closely covering the transmission means per se mth the indicated insulating sheath l and conductive sheath 5, and by grounding the latter in practically all cases from a point at the extreme end of the sheath near the cabinet C, which is ordinarily itself grounded, there results a very material reduction in the total loss of energy from the transmission means by radiation at the very high frequencies contemplated; and I have also found that a further reduction of said radiation loss is secured by further closely enveloping the first sheathed arrangement with insulating sheath 6 and conducting sheath 1, in which case it appears to be preferable not to conductively connect sheath 1 with any other element, and thus to, in effect, leave it 'floating so as to assume its own potential.

From the results I have obtained, I conceive that as the energy and/or frequency applied to the transmission means is or are increased, the

addition of insulating and conducting sheaths will act to keep the amount of radiation losses down, and, accordingly, I do not confine my present invention to any particular extent of sheathing.

As to the operation of the arrangement' of Fig;

2, it. is in all essential respects the same as that with the respective transmitted potentials thereof electrical alternating current energies having progressively maintainable frequencies from the order of megacycles to considerably above, transmission means comprising two maintained parallel conductors of the order of three feet in length terminated at each of their common ends by substantially equal resistances substantially equal in value to the value oi the characteristic surge impedance of said two conductors per se, and means for suppressing and thereby maintaining more nearly constant with variations in frequency accumulated inherent energy transmission losses by energy losing radiation from said conductors comprising a solid matter insulating sheath closely and fully enveloping said conductors and a conducting sheath closely and fully enveloping said insulating sheath grounded at its input end only.

2. The transmission means of claim 1 in which the combination of conductors and sheaths is reasonably ilexible.

3. The arrangement oi claim 1 in which a second solid matter-insulating sheath closely and fully envelopes said conducting sheath and a second conducting sheath closely and fully envelopes said second insulating sheath and is maintained free from any conductive relation to any other element and ground.

4. The arrangement of claim 1 in which a plurality of solid matter insulating sheaths and like plurality of conducting sheaths closely and fully envelope said conducting and one end grounded sheath, all maintained free from any conductive relation to any other element and ground.

5. The arrangement of claim 1 in which a housed source of variable in frequency from the order of 100 megacycles and considerably above electrical alternating currents is connected to supply the various energy inputs to the said transmission means.

HOWARD J. TYZZER.

Images