A antenna issue that has me stumped

Ok heres the scoop....

A cpl hrs ago i was able to achieve some really good #'s via my rig expert on a 19 plascadia...
As of about 1.5 yrs ago i installed a 102" on a 10" riser and again had excellent results on my analyzer..
Now i get excellent results on ch 40 but as freq drops they get worse..
I cant make 102" on the 10" riser any longer and useing a 7ft skip shooter i have the opposite issue its way better bellw cb band,i cant make it short enough to bring up the resonance point closer to center of the cb band...Same issue with a predator 10k

1 bond strap on back cab shock,2 on passenger door and 2 good and one questionable on drivers door....

I had a machine shop make me a 6" riser to play with a fresh 102(not tried that combo yet)but for fun i thought i would try the 7ft skip shooter..It tuned better way down in the 24 mghz area.....Doesnt make a diff with a normal stud either and i have tried 4 different ones..

Im at a total loss so im hopeing someone might have an idea of what im not seeing..

 

Nope it wasnt two hrs its been almost 2 yrs....When i put it on day one back about 1.5 yrs ago i had it almost perfectly where i wanted....Good #'s all a ross the band with my best being on somewhere between ch 18-20....So with seasonal changes and such a ways back i wanted just to chk things out cause i did hit some overhead wires at times and wondered if i knocked it outta wack..This was months and months ago now....So in breaking out the good ole aa55 zoom i noticed my best was now up on 40 vs mid band...Becajse of seasonal changes and rain,salt ect fron winter im guessing the lkck screw is siezed into my riser...So i cant loosen it to adjust,so i figured i would grab a new skip shooter(bought 3)and i cant make either of them short enought to bring up my ctr of the band tune..Tried with my 10k,same thing and i dont wanna cut whip to short....
In essence my 102 on the riser is siezed so i cant adjust it unless i ruin one or the other but even so my 102 on the 10" riser is maxed out in length but resonante on 40 vs 20...My skip shooters and 10k are resonante way to low and cant makem shorted to bring up resonance point....

So im just confused...1 case im not tall enough and the other im to tall and cant adjust either of them but was able to once before.....

Sorry for long reply..

 

Just looked at your reponce again..That was a typo of hrs,should been yrs..

 

I do have a 10" riser for the 102..I cut the threaded part off and slide it into the riser and turned lock screw tight once tuned..
I was in to much of a rush and didnt seal it up when it was all done..Now stainless and alumium have all corroded to sieze her up....
As i said to night stalker i cant make it any longer physically to llwer my resonance point cause its best up near ch 40,beside im over 13.6 when the wind hits it....
As for my 3 brand new skip shooters and a 10k i cant get them short enough...Just dont make sence..
I had a machine shop make me a solid 6" riser to put a brand new 102 on(useing threaded end this time so no adjustments possible)but i have yet to install....

When i use my aa55 zoom i got it set up so that coax is not seen as part of the connection..

 

Been my thoughts to but as i said the 102 on a 10" riser cant go long enough to drop my resonance point lower and on very same everything else(stud,coax,mount)i cant get a predator 10k on 20 odd in shaft and 3 brand new skip shooters to go short enough to being up the resonance point...
Im gonna try 2 fresh bond straps on passenger door and one more on rear cab shock mount to see..If that doesnt do anything ill try a freshly made riser that a new 102" will screw into vs the chopped end of the 102 that slide into a 10" riser thats on now.....
I would like to get a cpl bond straps from fire wall to chassie but i dont see how unless they end up a cpl feet long vs less than 12"-15"
Its got me stumped as bad as a shake/chatter in my trk @57 mph and up which acts like an outta ballance issue but not..
Front shocks changed,new front drums,tried a new set of wheels n tires,alignments were done ballance beads in tires,wheel weights tried and it doesnt change..Even goin down hill in netural its there....Funny thing is that it starts and stops randomly..
Been lime that almost its entire life....I swear this trk is tryin hard to drive to another round of weekend beers n bbq.. lol

 

Ok..Without changeing anything other than brand new 102 and the 6" riser from the ant stud,riser and 102 with end cut off to slip down inside the riser my #'s were almost the same..Maybe a hair better with new set up....
Older system is the 10"riser with a trimmed slightly 102(more like 101") with a 1" tall stud...New is riser(no stud) and brand new 102...Older is the bottom pic...

 

Here are new #'s(in above post) with new set up BUT i got power wires overhead,cars on either side and house behind me...How much that will squ the #'s some i have no idea how much....Ill see in abojt 12 hrs when i get to my delivery and an open space..
The weekend ill try some new bond straps..