Newbie needs help with Midland MXT575

[SargeDiesel]

First, I just joined the forum and wanted to say hello.

Second, I just purchased and installed a Midland MXT575, here are the details/questions:

I just installed my MXT575, using a shortened 12' midland (MTXA24) nmo cable(by CoolTech) attached to a Midland MXTA26 antenna. I have it mounted to a CoolTech stainless steel nmo mount next to the am/fm antenna on the passenger side hood cowl panel of my JT(Jeep Gladiator). I did run the power and antenna cables next to each other(??) and zip tied them to the vehicles wiring harness(??).... When testing, on channel 01(low power), I had SWR readings of 1.01 / FW-W 2.94 / RW-W .000 , but when I tested on channel 20(high power) I had SWR readings of 1.62 / FW-W 27 / RW-W 1.51.  -   First, I do not understand why there is a difference in SWR  ?  I am happy with the readings, but feel @ High power they need to be better and achieve at least 1:5:1 or below.  Secondly why is the output wattage so low for a 50 Watt radio ? I have seen this radio tested on YouTube several times and on low power it was 5.00+ watts and on high 49.00+ watts. I thought I might need to test into a dummy load for an accurate test, but during the YouTube test, the readings were the same whether testing into the antenna or a dummy load. I would prefer not to have to spend the $ on a dummy load if it is not needed.  I did just read that Midland GMRS antennas are pre-tuned to center channel (does that mean channel 11 ?) I can retest on channel 11 and there is some adjustment built into the antenna to shorten the length into the base, maybe this may improve the SWR, but what could possibly be causing the difference in SWR between Low/High power and the overall low output power... Thank you for any help.

Antenna, Cable , mount bundle (CoolTech) - https://www.cooltechllc.com/2018-jeep-wrangler-jl/139-gladiatorwrangler-front-antenna-mount.html#/91-front_bracket_options-bracket_nmo_adapter_12_midland_coax_mxta26_6db_antenna

[WRFE959]

I have two MXT 575's.  I get the advertised output.

I have spent quite a few hours working on this, and trying different solutions.  Here is my learning curve.

1) Operating Voltage.  As stated above, if your vehicle is not running, you will have a lower voltage into the radio.  That will reduce your output wattage.  To get 50W I have to have 13.8V input to the radio.

2)I did not read every response above, but I did not see anyone discussing coax loss.  If you are measuring power output at the end of your coax you have to account for coax loss.  Try measuring with a short piece of coax, or a better coax quality.  You should see an improvement in power output at the end of the coax.  

3) If you are measuring SWR at the radio, and you have a poor quality coax (either due to design or damage)  a low power will give you a false low SWR because of the high loss.  Low power to the antenna, and reflected power is lost in the line on the return.  If you are working on tuning, focus on the higher power outputs.  Use the repeater channels as these are where you will really be wanting to get the best response (467 mhz)

4) Pay attention to other elements in your coax line which you might not be thinking of.  I had a recent problem with high SWR after modifying my set up.  I was confident in the antenna and the radio.  After a few hours of confusion, I discovered it was a PL259 connector I added that was bad.  It created a high SWR and low power at the antenna.

5) MXT575 and MXTA26 are a great combination.  I am very pleased with my set up.  I have very good receive, get good compliments on the transmission quality.  I'm able to hit repeaters at 60+ miles away (obviously due to their great location).  But the 6db gain Midland is a good antenna.

Never stop learning.  There is always something new to learn in this hobby.

There will be people on here who love Midland and those who are in the opposite camp.  Midland makes good equipment.  Simple and easy to use.  Sometimes you get people on this forum who are commenting from their experience of Midland equipment from years past.  In other cases, some users prefer more options which might make another radio better for them.  But that brings more complexity too.

All that to say, stick with it.  Change something.  Measure.  Record.  Think.  Try Again.  Read more responses.  Repeat.