Replacing the 5" shafts with 10" on Wilson 2k

I've used Wilson antennas for years and I've always thought this to be true. Now there is a difference between the 1000 and 5000.......

 

Yes there is and always has been a difference between the coil of the 1000, 5000 and 2000 Wilson trucker antenna. The debate is if there is a difference for any of those coils depending on the size of the shaft under them. I say no.

 

I know, I was agreeing with your post. Agree on shaft length also. I'm not sure there is a difference in coils between the 1000 and 2000. They are the same size, unlike the 5000. I always figured they were the same coil, may not be though.

 

Someone in there response suggested that you would have to cut off 5 inches if you add 5 inches to the shaft under the antenna this would probably not be the case if this were true then it would also be true that if you added 50 inches to the bottom you would have to eliminate the whip and just put a 2 inch stub in place of the whip. Adding to the length of the shaft can change the match but it would maybe amount to an inch or so of whip difference and on occasion no change at all.. and in some cases you may have to make the whip setting a little higher is has more to do with the mirrors the truck doors the body of the truck as to how some antenna systems respond and exactly what you have to do get them to function as efficiently as possible...

 

I don't think this has been asked yet or said but have you checked your SWR's? and if so what are you seeing on channel 1, 19 and 40? I'm just curious

 

100 percent correct. Shaft length affects the needed stinger length. Also the higher the coil the greater the reduction in eddy currents which lose signal and distort the far field pattern. A 5 inch shaft is too short for me, 10" or 18" much preferred. I like to get the magnetic fields around the coil reasonably far away from any metal. Any higher than 18" is getting too top heavy especially in icing conditions and 18" gets near enough to center loading to produce a decent radiation pattern down the road. I have seen those who run 22" shafts (hopefully they mostly drive in the south) who claim great results. Beyond that is pushing it too far if you ask me.

 

The reason I posted this is in my forays across the Internet, I ran across a scan of a page listing the replacement parts for the Wilson 2000 antenna. On that page, there were two coils listed; one for 10" shaft and one for 5" shaft, and they had different part numbers.

Of course, I can't find that web page now...

It's quite possible that Wilson has changed things a bit and is now using the same coil. Given that you only need to trim 1.5" off the whip to compensate for adding 5" to the mast really says something about the coil efficiency... and it's not something good...

If only that was true... The problem is that loading coils become less and less effective the further you get from the feedpoint. You actually can do that, but what you end up with is more like the helically wound fiberglass antennas.

However, drop a nice big capacitance hat on top of a 50" mast, and you'll have a CB antenna that will work nearly as well as a 102" whip. Don't be surprised, though, if the other truckers start calling you "Daisy"...

 

Most truck drivers think that capacitance hat is some kind of ground plane. Or even worse they think it's a horizontal beam. LOL I kid you not, I stopped trying to splain it on 19 forever.