Home |
Search |
Today's Posts |
|
#1
|
|||
|
|||
|
#2
|
|||
|
|||
Mark Keith wrote:
"But I still feel I`m already building mine as well as they can be." Close the patent office! Best regards, Richard Harrison, KB5WZI |
#3
|
|||
|
|||
Mark Keith wrote: "But I still feel I`m already building mine as well as they can be." Close the patent office! Best regards, Richard Harrison, KB5WZI Bingo! In order not to rush Phreak into the patent office I will sit on some solutions for a while. :-) 3BUmmer |
#4
|
|||
|
|||
Hi All,
After having asked more than once for simple characteristics, taken Tom's speculative offering of 300µH (to which Yuri neither accepted nor rejected, nor offered amendment to, nor any value of his own, nor attempted to confirm or reject through his correspondence); I settled down to hammering through the values to make it ring using the other speculations of simple characteristics that remain wholly undisclosed (see enumeration above). The valuation offered by Tom was easily 1000% high. That I suggested that my model did not resonate came to no response by Yuri, who was quick to accept testimony of there being a current differential (which was also in reverse characteristic to those so-called measurements). Instead, I used what metrics were offered in the casual report and by evidence of photography to mock up the following: 0.375" Diameter copper (with losses) radiator length at 92"; a ground field of 60 #12 copper (with losses) radials; a 36.8267µH lumped coil (no losses attributed through R, no C); the lumped coil placed at the 46th inch (49.45%); the antenna placed over real ground; ground is of medium characteristic; the entire antenna/ground plane is 6" above actual ground; that comes to the following current distribution: 1 W2E1 1 0.00 2 1.0005 0.00 3 1.0012 -0.01 4 1.0019 -0.02 5 1.0027 -0.03 6 1.0035 -0.03 7 1.0043 -0.04 8 1.0051 -0.05 9 1.006 -0.05 10 1.0069 -0.06 11 1.0079 -0.06 12 1.0089 -0.07 13 1.0099 -0.07 14 1.011 -0.08 15 1.0121 -0.08 16 1.0132 -0.09 17 1.0144 -0.09 18 1.0156 -0.10 19 1.0169 -0.10 20 1.0182 -0.10 21 1.0195 -0.11 22 1.021 -0.11 23 1.0224 -0.12 24 1.024 -0.12 25 1.0256 -0.12 26 1.0273 -0.13 27 1.029 -0.13 28 1.0309 -0.13 29 1.0328 -0.14 30 1.0349 -0.14 31 1.0371 -0.14 32 1.0394 -0.14 33 1.0418 -0.15 34 1.0445 -0.15 35 1.0473 -0.15 36 1.0503 -0.16 37 1.0535 -0.16 38 1.0571 -0.16 39 1.061 -0.16 40 1.0653 -0.16 41 1.0702 -0.17 42 1.0759 -0.17 43 1.0826 -0.17 44 1.091 -0.17 45 1.1039 -0.17 46 1.1224 -0.18 47 1.0841 -0.18 48 1.0513 -0.18 49 1.0231 -0.18 50 .99652 -0.18 51 .97101 -0.18 52 .94623 -0.18 53 .92201 -0.19 54 .8982 -0.19 55 .87475 -0.19 56 .85159 -0.19 57 .82863 -0.19 58 .80587 -0.19 59 .78328 -0.20 60 .76083 -0.20 61 .73849 -0.20 62 .71627 -0.20 63 .69412 -0.20 64 .67205 -0.20 65 .65004 -0.20 66 .62807 -0.21 67 .60614 -0.21 68 .58425 -0.21 69 .56237 -0.21 70 .5405 -0.21 71 .51863 -0.21 72 .49675 -0.21 73 .47485 -0.22 74 .45294 -0.22 75 .43099 -0.22 76 .40898 -0.22 77 .38692 -0.22 78 .3648 -0.22 79 .34259 -0.23 80 .32028 -0.23 81 .29787 -0.23 82 .27531 -0.23 83 .25259 -0.23 84 .22969 -0.23 85 .20656 -0.23 86 .18316 -0.23 87 .15942 -0.24 88 .13523 -0.24 89 .11047 -0.24 90 .08486 -0.24 91 .05798 -0.24 92 Open .02713 -0.24 for each INCH of the radiator (and lumped coil) A visual description would be a constant current to the coil, and then a linear taper to the tip. The corresponding launch characteristic: 1.80dBi @ 29° By Decimating the lumped value across 10" (corresponding to the large solenoid's apparent size ascertained from the photographs); to 10 lumped values of 4.28078µH (adjusted to re-obtain resonance); placed at successive 1 inch segments (50..59); we find the following changes: 1 W2E1 1 0.00 2 1.0005 0.00 3 1.0011 -0.02 4 1.0017 -0.02 5 1.0024 -0.03 6 1.0031 -0.04 7 1.0039 -0.04 8 1.0047 -0.05 9 1.0054 -0.05 10 1.0063 -0.06 11 1.0071 -0.07 12 1.008 -0.07 13 1.0089 -0.08 14 1.0099 -0.08 15 1.0108 -0.09 16 1.0118 -0.09 17 1.0129 -0.10 18 1.014 -0.10 19 1.0151 -0.11 20 1.0162 -0.11 21 1.0174 -0.11 22 1.0187 -0.12 23 1.02 -0.12 24 1.0213 -0.13 25 1.0227 -0.13 26 1.0241 -0.13 27 1.0256 -0.14 28 1.0272 -0.14 29 1.0289 -0.14 30 1.0306 -0.15 31 1.0324 -0.15 32 1.0344 -0.15 33 1.0364 -0.16 34 1.0385 -0.16 35 1.0408 -0.16 36 1.0432 -0.17 37 1.0458 -0.17 38 1.0485 -0.17 39 1.0515 -0.17 40 1.0547 -0.18 41 1.0582 -0.18 42 1.0621 -0.18 43 1.0665 -0.18 44 1.0714 -0.18 45 1.0776 -0.19 46 1.0854 -0.19 47 1.0886 -0.19 48 1.0876 -0.19 49 1.083 -0.19 50 1.0748 -0.19 51 1.0633 -0.20 52 1.0484 -0.20 53 1.0301 -0.20 54 1.0084 -0.20 55 .98291 -0.20 56 .9533 -0.20 57 .92528 -0.20 58 .8983 -0.21 59 .87192 -0.21 60 .84597 -0.21 61 .82036 -0.21 62 .79502 -0.21 63 .7699 -0.21 64 .74494 -0.21 65 .72014 -0.22 66 .69545 -0.22 67 .67086 -0.22 68 .64635 -0.22 69 .62191 -0.22 70 .59751 -0.22 71 .57314 -0.22 72 .5488 -0.23 73 .52446 -0.23 74 .50012 -0.23 75 .47576 -0.23 76 .45136 -0.23 77 .42692 -0.23 78 .40243 -0.23 79 .37785 -0.24 80 .35318 -0.24 81 .32841 -0.24 82 .30348 -0.24 83 .2784 -0.24 84 .25312 -0.24 85 .22759 -0.24 86 .20178 -0.24 87 .1756 -0.25 88 .14894 -0.25 89 .12165 -0.25 90 .09344 -0.25 91 .06384 -0.25 92 Open .02987 -0.25 for each INCH of the radiator (and lumped coil) A visual description would be a constant current to the coil, and then a linear taper to the tip. It should be noted that for the protocol of solenoid assembly by lumped parts, the current into the solenoid does not equal the current out of the solenoid. The corresponding launch characteristic: 1.56dBi @ 29° Or roughly a quarter dB difference between the two (being generous, a 6% variation in absolute signal strength) Any surprises? Perhaps to the easily surprised, but a quarter dB variation hardly counts in the real world. Moment to moment propagation variation will eclipse or boost this easily (although employing 0.3dB to boost or eclipse is a strain on language). The real world is going to suffer the bitch of matching R (being resonant does not confer a 50 Ohm match to this small radiator). Does the current drop through the solenoid? Again, no surprise. Does it drop enough? Well that is arguable given the lack of attention to details of specifying the original test. Has any new precept been obtained that has not already been supplied? Insofar as the complaint of not seeing the current variation goes, that was answered long before the 350 itinerant postings that ignored it. Does the decimation offer enough accuracy? Angel population counts will undoubtedly be re-entered into with relish to make that illusionary exploration despite the obvious variation of so little as a quarter dB did for the first huge leap being the greatest difference that will be found. 73's Richard Clark, KB7QHC |
#5
|
|||
|
|||
"Richard Clark" wrote -
The valuation offered by Tom was easily 1000% high. .................................................. ............ Sounds a lot. Do you mean it was 10 or was it 11 times bigger? |
#6
|
|||
|
|||
|
#7
|
|||
|
|||
Mark Keith wrote:
"I`ve seen nothing so far to indicate we are designing in gross error or even noticible error." Neither have I. But, I`ve read several stimulating perceptions which were new to me and motivated me to investigate and improve my understanding. I am sorry My statement, "Close the patent office!" offended Mark. I have no doubt that Mark has optimized his mobil antennas. Forty years after Faraday suggested the existence of electric fields in about 1842, Heinrich Hertz built a spark transmitter and receiver. The receiver was just a loop with a gap which sparked when Hertz keyed his transmitter. It was resonant at 53 MHz or near the frequencies now assigned as TV Channel 2 in the USA. Hertz optimized his antennas for maximum transmission distance and achieved about 30 feet. In the last 160 years there have been many interesting antenna developments and more are yet to come. Most are not likely predictable. Best regards, Richard Harrison, KB5WZI |
#9
|
|||
|
|||
On 15 Nov 2003 11:00:19 -0800, (Art Unwin KB9MZ)
wrote: |Can you tell me where I can find what the orientation of coil cross |section does for efficiency ? Michaels ("Loading Coils for 160-Meter Antennas", QST, April 1990, pp 28-31) might help. |There are circular cross sections, edge wound cross sections and also |the ribbon type that Collins uses where the ribbon is coiled on a |adjacent coil former, why did they choose this method? I believe the Collins ribbon inductors were designed for variability, i.e., tunable without any sliding contacts as in roller inductors. |I am pursuing efficiency, reduction of losses and Collins have a great |reputation so which form is the state of the art especially with |corner flux density. |Another question is that if we split up an inductance into two parts |does the form factor include the summation of inductances or does the |distance inbetween |where coil linkage is not fully formed affect efficiency for the |worse. |Discussion like this thread hopefully will enlarge our education to |see if such things matter . Another question I struggle with is to put |another element inside the coil where there is max flux density but |again it can't be resolved by modeling. With the multi antenna experts |onboard it is always a possibility that a modicom of information will |be provided that will benefit all. |As far as inductances, all is not known to my mind and I always would |like to be privy to more information, and not because I want to build |a whip Another interesting reference is Rhea ("Filters and an Oscillator Using a New Solenoid Model", Applied Microwave & Wireless, November 2000, pp 30-42) In a nutshell, his premise is that the classic inductor model is in error, particularly with respect interwinding capacitance. Some other articles that should be read by all participating in this thread are by Cebik. http://www.cebik.com/amod/amod13.html http://www.cebik.com/amod/amod14.html |
#10
|
|||
|
|||
Wes Stewart wrote in message . ..
On 15 Nov 2003 11:00:19 -0800, (Art Unwin KB9MZ) wrote: |Can you tell me where I can find what the orientation of coil cross |section does for efficiency ? Michaels ("Loading Coils for 160-Meter Antennas", QST, April 1990, pp 28-31) might help. |There are circular cross sections, edge wound cross sections and also |the ribbon type that Collins uses where the ribbon is coiled on a |adjacent coil former, why did they choose this method? I believe the Collins ribbon inductors were designed for variability, i.e., tunable without any sliding contacts as in roller inductors. |I am pursuing efficiency, reduction of losses and Collins have a great |reputation so which form is the state of the art especially with |corner flux density. |Another question is that if we split up an inductance into two parts |does the form factor include the summation of inductances or does the |distance inbetween |where coil linkage is not fully formed affect efficiency for the |worse. |Discussion like this thread hopefully will enlarge our education to |see if such things matter . Another question I struggle with is to put |another element inside the coil where there is max flux density but |again it can't be resolved by modeling. With the multi antenna experts |onboard it is always a possibility that a modicom of information will |be provided that will benefit all. |As far as inductances, all is not known to my mind and I always would |like to be privy to more information, and not because I want to build |a whip Another interesting reference is Rhea ("Filters and an Oscillator Using a New Solenoid Model", Applied Microwave & Wireless, November 2000, pp 30-42) In a nutshell, his premise is that the classic inductor model is in error, particularly with respect interwinding capacitance. Some other articles that should be read by all participating in this thread are by Cebik. http://www.cebik.com/amod/amod13.html http://www.cebik.com/amod/amod14.html Thank you for those references Wes. I really didn't expect to hear from you again. I now have the computor program to simulate my actual antenna so efficiency is now of major importance ,I can up my efficiency to 50 per cent by hanging a wire down from the dipole ends which I am not comfortable about and would rather aproach the coil for loss reduction and go for a beam setup by using the radiation efficiently by making it fully directional stead of figure 8 form and hopefully I can get those extracts Reg I tried to enter your page once but I am so computor incompetant. Looked at a tank circuit today and it was wound flat ribbon form! Looking forward to looking at this fresh info Many thanks to both of you Art |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Inverted ground plane antenna: compared with normal GP and low dipole. | Antenna | |||
Smith Chart Quiz | Antenna | |||
QST Article: An Easy to Build, Dual-Band Collinear Antenna | Antenna | |||
Eznec modeling loading coils? | Antenna |