wilson antennas...gone insane
first i would like to thank everyone for their efforts in trying to help me out.
this is the setup, and how i went about doing the testing; both are mag mounts, i have no trouble setting the swr with the amplifier off, these problems are being seen with the amplifier on, and yes i know that the t.s. amps hare notorious for having swr issues due to having a " generic" tuned output. there is a twist at the end that i don't understand...bear with me.
current setup: i am running a rci6900f25 into a t.s.500v then into a yeasu ys-60 meter then to the antenna, the jumper from the radio to the amp is LMR240ultra at 6". the jumper from the amp to swr meter is LMR240 ultra at 6" and then the antenna coax rg8x at 17'6"..the setup is in a full sized vehicle with extensive bonding done to it..i.e hood to firewall, fenders to firewall, engine to chasis, doors to body, body to chasis. i used avaition grade 5/8" tinned ground braid with gold plated connectors that were opened to accept the full width of the ground braid. the amplifier and radio have five of these, one from radio at the so239 connection, and four from amplifier from the back of the heatsink terminating to a single point bolted right to the steel floorboard under the carpet. they are all under 9"long. before itwasall said and done i think i used almost 50' of the ground braid. and this was done years ago before the inital installation.
now,i ran a wilson 1000 with this setup for about seven years with no swr issues, and since april ran both 10 and 11 meters with the 1000 with no swr problems. i had two different whips cut for the center both bands and got fed up with climbing up there to change out the whips everytime i wanted to change bands.
now i tried setting up the wilson 5000 by itself.the whip length was 62" i tried to set it up for 11 meter and the lowest swr i could get by raising or lowering the whip was 1.6.1 with a abrupt jump on either side of the swr curve. so i tried a longer whip as i had a 66" whip here in case i ran into problems, and found the same problem. so i figured i would try to set it up for 10 meters using the 571/2" whip as suggested by wilson and found the same issue a 1.6.1 swr with an abrupt jump on either side of the curveat 28.500. rasing or lowering the whip had no effect at lowering the swr. and that 66" whip described previously was gradually trimmed down to acheave that 1.6.1 swr.
now for some reason when i tried setting the wilson 1000 back up to the way i had it prevoiusly i found i couldn't set it back up. then went through the before mentioned process to try to bring the swr down with no luck.
now this is where it gets interesting, i ordered one of those sirio turbo 5000 since i herd it was a failry decient antenna so i wanted to give it a try. when i got the antenna( of course i forgot to order the mag mount that goes with it) so i tested it on one of the wilson mags, now at first i seen the same problem except the lowest swr i could get on 11 meter was 2.0.1. and that was with adjusting the whip, so i decided to play around with adding jumpers to it and when i got to adding 54 1/2" to the existing 17' 6" of rg8x coax it gave me some 2 MHz of bandwidth with the amp on on 11 meter at a swrof 1.5.1 at either edge of the curve with 1.0.1 at the center.
. so, when the mag came in i tested it with that lower grade rg58c/u coax that it came with at a length of 12'. and the bandwidth wasent that impressive probably .8 MHz with a swr of 1.4.1. so i figured i would change the coax out to the LMR240 ultra. i did the calculations 492/27.025=18.205x0.84=15.292, so i cut the length to 15' 3" soldered it to the mag and the connector and tried it and seen the same 2 MHz of bandwidth with the same swr curve. i used the 27.025 figure as i read that is the resonant frequency of the sirio antenna. so in the end what is the major difference between these three antennas? i understand that without an analizer i am in the dark and i am only assuming here but perhaps the wilsons are suffering from some form of reactance, and or capacitance issue? i am not sure...the best i can figure. a penny for your thoughts gentelman.