SWR help

[ScotM]

I installed a midland 275, with the magnetic antenna mount and the 32” MXTA26. I’m using an swr meter and getting 1.74 reading. No matter where I put the antenna- on the ground, on the ground on a steel plate, on the Jeep. Etc. I’m using the sw33 surecom meter, cause I had that available. If I put the antenna on my epoxy floor, not grounded, I get a 1.96 swr. It has a 20 ft cord, all measuring was done without it being coiled. Anyone else measure their swr and find it higher than ideal? Not sure what to do next, since midland says the antenna is optimized for the mxt275. Maybe my meter is not the best? Thoughts and advice would be appreciated.

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[Pape]

I installed a midland 275, with the magnetic antenna mount and the 32” MXTA26. I’m using an swr meter and getting 1.74 reading. No matter where I put the antenna- on the ground, on the ground on a steel plate, on the Jeep. Etc. I’m using the sw33 surecom meter, cause I had that available. If I put the antenna on my epoxy floor, not grounded, I get a 1.96 swr. It has a 20 ft cord, all measuring was done without it being coiled. Anyone else measure their swr and find it higher than ideal? Not sure what to do next, since midland says the antenna is optimized for the mxt275. Maybe my meter is not the best? Thoughts and advice would be appreciated.

What channel did you test the swr ?
Under 2 is acceptable in my book.
Usually you test at 1 and 40 will tell you if the antenna is to long ot two short, tahn on your main frequency.

 

[Still Jeepin]

There are couple things to try. Check swr on channel 1 and then 22. Compare the numbers. If it’s higher on 22 the antenna needs to be longer. And opposite for higher on ch 1 shorter. There’s some adjustment you can adjust with the set screw on the on the spring.

I installed one a while back and ended up trimming about a 1/2” of to get a decent swr.

Good luck, Gary

 

[ScotM]

What channel did you test the swr ?
Under 2 is acceptable in my book.
Usually you test at 1 and 40 will tell you if the antenna is to long ot two short, tahn on your main frequency.

I checked on Chanel 18

 

[Terrymo]

@Nokones
@THAW

Did you also test in an open area away from any obstructions and get the same results?

Here’s a good thread in case you didn’t already see it including someone of my fumbling around pretending to be a radio dork.

 

[Terrymo]

I don’t think that Midland antenna is tunable? I see mixed answers from Midland on ground plane regarding that antenna. One answer says not required another saying it would be best. Also in my limited but possibly wrong information anything under 2.0 is fine for normal trail use,

 

[ScotM]

There are couple things to try. Check swr on channel 1 and then 22. Compare the numbers. If it’s higher on 22 the antenna needs to be longer. And opposite for higher on ch 1 shorter. There’s some adjustment you can adjust with the set screw on the on the spring.

I installed one a while back and ended up trimming about a 1/2” of to get a decent swr.

Good luck, Gary

Thanks I”ll do that this afternoon

 

[ScotM]

I don’t thist Midland antenna id tunable? I see mixed answers from Midland on ground plane regarding that antenna. One answer says not required another saying it would be best. Also in my limited but possibly wrong information anything under 2.0 is fine for normal trail use,

I’ll try the set screws first and see if I can shorten it up. I checked outdoors, but I live around hills. I”ll try it at the top of my hill, nothing but clear views up there.

 

[Terrymo]

Sorry here’s the thread
https://www.jlwranglerforums.com/fo...an-install-diy-on-2025-4-door-rubicon.161639/

 

[Pape]

I checked on Chanel 18

As pointed out, you are already in good shape but if you want to go down in perfection test and tune the wip.

 

[2nd 392]

@Nokones
@THAW

Did you also test in an open area away from any obstructions and get the same results?

Here’s a good thread in case you didn’t already see it including someone of my fumbling around pretending to be a radio dork.

Open area with the doors closed too.

 

[ScotM]

Sorry here’s the thread
https://www.jlwranglerforums.com/fo...an-install-diy-on-2025-4-door-rubicon.161639/

One post got me a little hesitant. About tapping into the jeeps power might hurt the canbus, but midland supplies a 12v plug for the 275, so I imagine my tapping into the 12v circuit at the socket should be acceptable. Maybe the 50 watt 575 needs the direct battery power, not the 275, since it doesn’t come with that option.

 

[THAW]

Experiment with positioning the antenna to create an optimal ground plane. What did the steel plate setup look like?

At 1.76:1 you're transmitting about 92% of your radio power. So not bad, and the reflected power is low enough it won't hurt the radio.

 

[ScotM]

I’m mounting the antennas on the back of the Jeep, and going to run the ground strap with the antenna cable and use the ground in the passenger wheel well. It just seems cleaner than trying to drag the grounding strap under the vehicle to the chassis.. thoughts on that?

 

[Nokones]

This is where I am running a ground wire to the chassis from the rear. It is run underneath the rear tailgate rubber seal. You can use any bolt underneath to terminate the ground wire.

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