Multiple Antenna Question for 2M/70CM

[mmckenna]

I had a Spot satellite communicator first, and it was a piece of junk so I sold it and got the inReach. Much better service with the Iridium satellite network.

I used mine the other day, and realized it was really dirty from being on my pack while doing some fast ATV rides. I was able to just dunk it in the river and wipe it down. Not sure how the Spot units do with water resistance.

 

[K9DWB]

Nice results there. So after all that equipment being strapped in, is there any room for you? Looks a bit like a chopper cockpit or that of an OTR truck driver. Again, you did good and you like the results, that's what counts the most. That COMPACtenna looks very nice tucked in that way.

 

[vagrant]

I went with the inReach SE+ specifically because of the improved battery life over the mini. I also found a resource to self install the SE battery (actually the whole backside) whenever the battery finally fails. Amazon had a crazy discount for what seems like one day and I got it NIB for $280 +tax. plus $100 off of that by applying for and using some Amazon friendly credit card. Anyways, a top up of the mini while one is sleeping and it's good to go.

I also figured out contact text messaging needs the number in a straight forward format, eg. +17085551212 and no symbols. Perhaps I will get to enjoy it more in 2021 when the fires are out and the various California forests open back up.

 

[mmckenna]

I went with the inReach SE+ specifically because of the improved battery life over the mini. I also found a resource to self install the SE battery (actually the whole backside) whenever the battery finally fails. Amazon had a crazy discount for what seems like one day and I got it NIB for $280 +tax. plus $100 off of that by applying for and using some Amazon friendly credit card. Anyways, a top up of the mini while one is sleeping and it's good to go.

That's a heck of a good deal.
I keep mine turned off as I'm not expecting incoming messages. I usually turn it on periodically through the day, and only check in at night. I looked at the battery replacement options before purchasing, wasn't going to fall into that trap.

I also figured out contact text messaging needs the number in a straight forward format, eg. +17085551212 and no symbols. Perhaps I will get to enjoy it more in 2021 when the fires are out and the various California forests open back up.

Yeah, that's a big 10-4. I was up through very northern California this week, from Mt. Shasta North and West, a couple of big fires burning up that way. Cut out to the coast and down Highway 1 all the way, never did see the sun.
Two of my sites have burned over, and while the repeaters are still working, I know there is some damage. Still waiting for the all clear to go in and take a look.

 

[ccg_ga]

I have a couple of replies for tommorow, but on the wildfires I hope you guys in CA are safe. I’m a long way from there in GA but that is some crazy stuff with all the active fires right now. I was reading about them today.

 

[mmckenna]

I have a couple of replies for tommorow, but on the wildfires I hope you guys in CA are safe. I’m a long way from there in GA but that is some crazy stuff with all the active fires right now. I was reading about them today.

Thanks.
We have a few people in our department that lost their homes. A few other people I know lost everything but the clothes on their backs. Unfortunately not much can be done, some of this will have to burn out on its own, and that's probably a good thing. Not enough resources to go around. I know the Canadians and Australians are rolling in to assist, but it's going to take more than that. I hate to say it, but some of this stuff needs to burn (not the homes, the grasslands and forests) it's natural for it to happen. Too many people living on the fringes assume that either the fires will never reach them, or that the fire agencies will protect them. That thinking has to change.

 

[ccg_ga]

Nice results there. So after all that equipment being strapped in, is there any room for you? Looks a bit like a chopper cockpit or that of an OTR truck driver. Again, you did good and you like the results, that's what counts the most. That COMPACtenna looks very nice tucked in that way.

Ha, I guess it does! As you can see I like my gadgets. While there is plenty of room for me, it does get pretty tight whenever my wife and daughter come with me. Once you put her car seat in the back there is barely enough room for my wife to sit in the front seat.

I have thought about trading up to one of the newer 4 door Jeep JL's, but it gets really expensive fast once you start with the off-road mods. Plus there is a rumor that Jeep is going to do a production JL Wrangler with a 392 V8 in it...

I went with the inReach SE+ specifically because of the improved battery life over the mini. I also found a resource to self install the SE battery (actually the whole backside) whenever the battery finally fails. Amazon had a crazy discount for what seems like one day and I got it NIB for $280 +tax. plus $100 off of that by applying for and using some Amazon friendly credit card. Anyways, a top up of the mini while one is sleeping and it's good to go.

I also figured out contact text messaging needs the number in a straight forward format, eg. +17085551212 and no symbols. Perhaps I will get to enjoy it more in 2021 when the fires are out and the various California forests open back up.

That is a good deal. I ended up buying my inReach Explorer + off of Facebook Marketplace. I paid $300 for it, and it was a factory replacement that Garmin sent the previous owner because of a defect in the unit they had before. I think the going rate for a new one was $450 at the time.

I used mine the other day, and realized it was really dirty from being on my pack while doing some fast ATV rides. I was able to just dunk it in the river and wipe it down. Not sure how the Spot units do with water resistance.

So I had the Spot X which is the one with the physical keyboard. I think it was rated to some degree of water resistance, but I never tested it out and is was pretty much always in the Jeep the couple of times that I took it. The outbound messages would fail more often that they didn't, it was horrible in any tree cover and it when the messages did send, it took forever.

Plus, their website was down often, which included the tracking map if you were sending position messages. I actually just tried to check their site to see about the water resistance and it is actually down right now.

Thankfully their customer service let me out of the contract - I signed up for month-to-month service but there was a 12-month minimum. They actually cancelled the service the day I called in and I didn't have to pay the remaining balance,

 

[ccg_ga]

Thanks.
We have a few people in our department that lost their homes. A few other people I know lost everything but the clothes on their backs. Unfortunately not much can be done, some of this will have to burn out on its own, and that's probably a good thing. Not enough resources to go around. I know the Canadians and Australians are rolling in to assist, but it's going to take more than that. I hate to say it, but some of this stuff needs to burn (not the homes, the grasslands and forests) it's natural for it to happen. Too many people living on the fringes assume that either the fires will never reach them, or that the fire agencies will protect them. That thinking has to change.

I can't even imagine that. Out here we sometimes get tornados or sometimes the leftover remnants of a hurricane or tropical storm, but nothing like the wildfires. I think the article I read yesterday in the WSJ said there were 28 active fires..

 

[mmckenna]

Plus there is a rumor that Jeep is going to do a production JL Wrangler with a 392 V8 in it...

Sweet Mother of Pearl that would be awesome. But I'd probably end up hurting myself...

So I had the Spot X which is the one with the physical keyboard…...They actually cancelled the service the day I called in and I didn't have to pay the remaining balance,

Thanks, that's sort of along the lines of what I heard. I've been happy with the InReach. Only issue I had was when I was in a very deep canyon and it took a few minutes to get the message out. Wasn't an emergency, just a check in, so not a big deal.

 

[ccg_ga]

Sweet Mother of Pearl that would be awesome. But I'd probably end up hurting myself...

Yeah buddy, if they do I don't think I will be able to resist.. it would be the first production V8 since AMC offered the 304 on the CJ7s.

The V8 Jeep Wrangler Rubicon 392 Is Coming to Production: Report

An alleged Jeep insider reports seeing 30 prototypes being built in Ohio.

www.thedrive.com

 

[K9DWB]

FWIW my younger brother had an '80s Jeep modded with a Chevy V8 stuffed inside. Interesting, and had the HP packed in. If memory is accurate, it was a 4 bbl carb 350 cubic incher probably from a '70s Chevy of some sort. As said it was interesting, but when lil brother bought it, it was in semi trashed state. Likely the reason it was for sale in the first place. It always seemed like it was a semi drivable Sanford N Son trashed truck. Pardon my topic drift. I'm an old gear head, as my first car was an Oldsmobile Cutlass Supreme with the "base" 350 V8 and single exhaust that had a Hoover vacuum for a 4 bbl carb. Managed about 10 MPG.

 

[ccg_ga]

Part 2 of the write-up - covers how to mount the MXT400 and make the custom mounting brackets for the IC-2730A

Part 2 - Midland MXT400 MicroMobile GMRS Radio & Icom IC-2730A Mobile Ham Radio Install in a Jeep Wrangler - Part 2 - Southeast 4x4 Trails

Click for step-by-step instructions on how to make custom mounting brackets for a Midland MXT400 GRMS radio and Icom IC-2730A ham radio.

southeast4x4trails.com

 

[K9DWB]

It sounds like a great DIY for you young bucks. I'm in good shape for 71, even though I was born in '69.

 

[ccg_ga]

It sounds like a great DIY for you young bucks. I'm in good shape for 71, even though I was born in '69.

After sweating outside in GA July heat for about a week working on this I started to question my sanity. Thankfully it's all wrapped up now that it's starting to get cooler!

 

[K9DWB]

Feel like giving us a picture or two? I'd like to see your project if/when you're done.

 

[ccg_ga]

Feel like giving us a picture or two? I'd like to see your project if/when you're done.

I actually posted photos throughout this thread of the project. Start on page 3 for the MXT400 and IC-2730A mounts and antenna mounts, more on page 8 for the Lind shutdown timer and re-wiring the system to use that and there are photos of the SDS100 and COMPACtenna mount starting on page 8. There are additional photos on the blog link post above as weel

 

[K9DWB]

Thanks for the reminder. My old timers is showing.

 

[ccg_ga]

Ok, so I am working on part 3 of the installation write-up which covers installing the antennas. I have spent probably 3-4 hours reading posts on here about "ground plane" and "no ground plane" antennas, other pages, articles, YouTube videos, the ARRL handbook, etc.

While I feel like I have the no ground plane concept fairly straight in my head, I'm struggling to boil it down for the purposes of the write-up. What I am trying to do is illustrate why a no ground plane antenna is important when mounting the antennas on a Jeep, but not go down a rabbit hole on the technical details. The assumption is that the reader is your average Jeep owner that just wants to get a good radio setup.

So, here is what I have come up with so far. I would greatly appreciate any feedback or corrections, as I'm sure I have oversimplified or misstated something:

When it comes to installing antennas for mobile radios on vehicles, the generally accepted "ideal" scenario is one where you are able to mount the antenna on top of a *metal* roof on the vehicle. The antenna is mounted on the roof by either drilling a hole through the roof and installing the antenna mount (such as an NMO) or by using a magnetic mounting base. Either of those mounting methods allows the metal surface of the roof to connect to the antenna, where the metal roof of the vehicle services as what is called a "ground plane" (Wikipedia). A ground plane is a "flat or nearly flat horizontal reflecting surface that serves as part of the antenna and reflects the radio waves from the other antenna elements."

So, if you are mounting the antennas on a Jeep you do not have a metal roof - it's either a fabric material if you run a soft-top or fiberglass if you run a hardtop. Yes, there are other flat metal surfaces to mount the antenna on, but the size/area of the flat metal surface is important if it is going to act as a ground plane for the radio antenna(s). If you are using a GMRS radio, 2 meter or 70cm ham radio, there isn't a flat metal surface large enough on the Jeep to serve as a ground plane.

What is important is that you use what is called a "no ground plane" antenna for the frequency that your radio will transmit on. Both of the antennas that I installed are "no ground plane" antennas - the Larsen NMO450CHW for the MXT400 GMRS radio and the Larsen NMO 2/70B for the 2-meter/7cm IC-2730A ham radio. In technical terms, both the NMO2/70B and NMO450CHW are 1/2 wave antennas which means that the length of the antenna whip (long metal piece) is equal to 1/2 the length of the full RF wave for the bands they are designed to operate on. This length allows the antennas to work without a ground plane.

The information available on "no ground plane" and "ground plane" antenna setups is virtually endless. If you would like to learn more about these concepts, Google either of those terms but beware it gets very technical very quickly. My goal in this post is to highlight why a "no ground plane" antenna is the correct choice for these radios when they are mounted on a Jeep.

 

[cmdrwill]

You are correct, "no groundplane antenna" was NOT covered in Antenna 101.

 

[K9DWB]

I have no issues with how you described the reasoning behind choosing no ground plane. Good job.