Base Real tall antenna imax 2000 Problem

[DC Star (3831)]

Hello fellow cb'ers. I have a unique problem. I operate tower cranes, currently I'm in one that's 350' to the base of the mast. The crane is also grounded at the base. I run a imax 2000 mounted to the very top of a 10' sprinkler pipe that's mounted to the very top of the crane.
Now my problem is swr's. Right now they're extremely high
I've tried grounding the mast, tuning the rings, but I'm not sure if I am grounding it properly. I also don't know if the height is a issue either. Any feedback, theories? 73's

 

[TheRealPorkchop]

I have absolutely no useful input here but I just want to say that’s

 

[JAF0]

I'd guess either a coax issue or one of the newer Imax' which seem to have this issue right out of the box far too often.

All that a good Imax requires is a minimum of 9' of coax above any choke or 9' ground plane radials.

Do you have a new Imax or has it worked fine until this current installation?

 

[DC Star (3831)]

I have absolutely no useful input here but I just want to say that’s

View attachment 27894
View attachment 27895

Lmao

 

[DC Star (3831)]

I'd guess either a coax issue or one of the newer Imax' which seem to have this issue right out of the box far too often.

All that a good Imax requires is a minimum of 9' of coax above any choke or 9' ground plane radials.

Do you have a new Imax or has it worked fine until this current installation?

It's fairly new. It's my 2nd installation with it. I generally always have this problem, & right out of the box it did the same thing.

 

[DC Star (3831)]

Now I haven't done any grounding of the antenna as of yet. Crane just went up, so I'm trying to not do what I usually do. I thought I would get some fresh theories or ideas. Should I ground the antenna closest to the bottom of the mast?

 

[JAF0]

There's plenty of metal up there to satisfy the requirements for a counterpoise, try checking the coax, my guess is a smashed point or bad connector(s)

It would also be a good idea to put an analyzer on the antenna to make sure it's not a bad Imax.

If it was me I'd put a sirio gainmaster up there.

 

[DC Star (3831)]

There's plenty of metal up there to satisfy the requirements for a counterpoise, try checking the coax, my guess is a smashed point or bad connector(s)

It would also be a good idea to put an analyzer on the antenna to make sure it's not a bad Imax.

If it was me I'd put a sirio gainmaster up there.

B4 I actually mounted it I checked it with the analyzer & I was seeing about a 2.1. Hmmmm, but I haven't checked it with the analyzer since I mounted it. Im going to chk now. What are the advantages of a sirio, and do you know how it holds up in wind?

 

[RT431]

I will echo JAFO.
Test PL connectors inspect coax physically and with an ohm meter. If all checks good, then id say you have a defective antenna.

 

[JAF0]

B4 I actually mounted it I checked it with the analyzer & I was seeing about a 2.1. Hmmmm, but I haven't checked it with the analyzer since I mounted it. Im going to chk now. What are the advantages of a sirio, and do you know how it holds up in wind?

Id trust a gainmaster up to 80-90mph wind, and they seem to work well when new unlike the new Imax or Max 2000s.
Keep the power under a Kw into a gainmaster.

When analyzing an Imax make sure you're using at least a 9' mast or 9' of coax.

 

[W4KVW]

Looks as if there is metal to one side of it where it is mounted which could be an issue. Can't really tell from the photo? On the SWR meter it looks like about a 1.5.1 SWR which is far from terrible & I think very acceptable on any antenna if that is the true SWR which there is only ONE. No SWR's. As for as a counterpoise I don't think it requires one.

SIX-SHOOTER

 

[338_MtRushmore]

What kind of clamps are those?

 

[DC Star (3831)]

Looks as if there is metal to one side of it where it is mounted which could be an issue. Can't really tell from the photo? On the SWR meter it looks like about a 1.5.1 SWR which is far from terrible & I think very acceptable on any antenna if that is the true SWR which there is only ONE. No SWR's. As for as a counterpoise I don't think it requires one.

SIX-SHOOTER

Hey Six thanks for the comeback. So I'm new to this cross needle meter. I thought that where the 2 needles crossed that was my reading. So is it where the needle crosses the actual red hash marks?

 

[DC Star (3831)]

What kind of clamps are those?

Which clamps on the mast to the crane or antenna to the mast?

 

[DC Star (3831)]

Looks as if there is metal to one side of it where it is mounted which could be an issue. Can't really tell from the photo? On the SWR meter it looks like about a 1.5.1 SWR which is far from terrible & I think very acceptable on any antenna if that is the true SWR which there is only ONE. No SWR's. As for as a counterpoise I don't think it requires one.

SIX-SHOOTER