Mobile New 102” Whip & 4” Spring - Trimmed SWR

[AndrewGS]

I got a new stainless steel 102” whip and 4” spring. My mount gives about a 2” rise, so there’s about 108” of antenna. I checked SWR today and it’s not too bad, but I figured I could do a little better. Here are my readings:

With 4” Spring
CH 1 - 1.4
CH 20 - 1.6
CH 40 - 1.8

Without 4” Spring
CH 1 - 1.3
CH 20 - 1.4
CH 40 - 1.5

I trimmed 5-3/8" off the top and that put the SWR at 1.4 across the band with the spring. I'll have to wait until my new DX-94HP arrives to see how broadbanded it is. I think that's acceptable.

I also ordered a corona ball since I cut the little stock one off when I trimmed it.



Here are a couple of pics of my mounting. And yes, it's properly bonded for ground plane.

 

[AndrewGS]

Sorry, wrong corona ball.

 

[AndrewGS]

OK, so I put it on an analyzer this morning.



Looks like my PRO520XL and MFJ meter served me well. lol

 

[undertaker]

Looks good..

 

[Robb]

V. Good.

 

[camaro1]

personally I think I would have taken the spring out instead of cutting the whip down,, your going to need to tie the whip to something with the spring on there its going to be flopping all over the place when you get on the highway

 

[Mudfoot]

...or get a beefier spring.

 

[AndrewGS]

personally I think I would have taken the spring out instead of cutting the whip down,, your going to need to tie the whip to something with the spring on there its going to be flopping all over the place when you get on the highway

It's a heavy-duty ass stainless spring. It'll keep the whip from bending if it hits something but on the highway it's rigid. Only the upper third of the whip bends back a little on the highway.

 

[Mudfoot]

Have you checked impedance while driving at highway speeds?

 

[AndrewGS]

Have you checked impedance while driving at highway speeds?

Not yet. I'll have to do that this week.

 

[357magnum]

Have you checked impedance while driving at highway speeds?

And they say no texting and driving ? I hope you are using cruise control .

 

[AndrewGS]

Sitting in the driveway.



At 75MPH.

 

[AndrewGS]

OK, got my corona ball in today and installed it. Had to trim a bit more off the whip as expected, but I think I've got it set in the sweet spot now.