Lscott

I think today will be one where Ham, GMRS and CB radio is going to get a bit of a workout. People driving around trying to beat out the traffic to find a good location to view the eclipse. With the weather forecast being crummy in some areas getting up to date viewing conditions is going to cause a lot of last minute scrambling to get to a better site.

Yea, plenty of traffic today on a set of ham repeaters that are not normally linked.

I think today will be one where Ham, GMRS and CB radio is going to get a bit of a workout. People driving around trying to beat out the traffic to find a good location to view the eclipse. With the weather forecast being crummy in some areas getting up to date viewing conditions is going to cause a lot of last minute scrambling to get to a better site.

Around the Detroit area 2M and 70cm are dead most of the time. Many of the repeaters see little use. 
 
On 70cm with 20MHz of spectrum it’s easy to get lost in it if you’re looking to talk to somebody. 
 
On GMRS you only have a handful of frequencies to use so it doesn’t take much to find activity. On the Ham 70cm band yeah you have some grumpy people. With GMRS it’s geared for “family” use and the range of permissible uses is far greater than the Ham band allows. 
 
On GMRS everyone has the same type of license call, none of the 1x2, 1x3 etc. calls depending your license class. Some Hams won’t talk to somebody with a tech class call for example. On GMRS nobody cares how much DX you’ve worked, how fast you can send and receive CW, you run 1500 watts into an antenna on a 200 foot tower in your yard etc., it levels the field.

You want a coax switch. Be sure you get one that is rated up pass the highest frequency you intend to use. Since you're stuck using SO-239 sockets on it you have to be careful to get the right insulator and socket design type.
Most SO-239 sockets for CB radio or HF work may use the crappy red or brown Bakelite insulating material around the center pin. DON'T use those!. These will cause SWR issues.
The better choice is when the material is white. That would typically be Delron or Teflon. While better than the above I would only recommend it for VHF and below.
The best is where the center pin is supported by what looks like a spoked wheel design around the center pin. That gives the interior of the socket mostly air and results in a socket impedance closer to 50 ohms, matching the radio and coax, which will mitigate SWR problems.
https://forums.mygmrs.com/gallery/image/431-coax-switchjpg/
 

Yes.  Ham stations in some counties and city’s are exempt from some rules while gmrs stations are not.  Same at some home owners associations.  Might be a good reason to get your ham license even if you don’t use it. 

Rumor has it that Anytone is buying Motorola's land mobile radio division too.

You sure you are not simulating nuclear weapons?  Those are serious mushroom clouds. 🤔🤪

If anyone is interested in messing around with antenna simulations the software is now freely available.
https://www.eznec.com/
I've attached some models I've played around with in the past.
Magnet Mount - Rev 2.EZ Magnet Mount Ham and MURS.EZ Ham and GMRS Magnet Mount.EZ GMRS J-Pole Rev 3.EZ GMRS 11 Element Yagi Rev 2.EZ FRS-GMRS Gnd Plane With Radials.EZ 4 Bay Anetnna MURS.EZ

OK.
I simulated a simple magnet mount 1/4 wave MURS antenna. The frequency was selected to be about in the middle of the band. The results looks good. The match and radiation pattern look like what I would expect.
The exact same antenna was then run at a frequency about in the middle of the GMRS band, between the simplex and repeater input frequencies.
As you can see the match short of looks OK on GMRS, however most of the RF power shoots up at a very high angle uselessly into space. I guess if GMRS has satellites in low earth orbit it might be a good antenna. For normal ground work most of the power is wasted. 
This is what I was getting at in my prior post comments.

Its pretty common to run a 2m/70cm antenna and a cross repeat radio with no desensing on either band.  Its one radio using the same physical antenna, listening on two bands at once, or transmitting on one band and listening on the other. Using 2 physical antennas wouldn't be much different.
I run a 2m antenna on the rear passenger side, and a gmrs antenna on the rear drive side. They feed into a diplexer (instead of a switch) at the back, then feed into 1 coax going to a single radio. No desensing, interference, coupling, or other issues that I can find on an analyzer or hear in performance.
You will get some desensing on uhf if the frequency separation is <1mhz. I start picking up interference at around 800khz. But the antennas are only 4feet apart.

Rumor has it that Anytone is buying Motorola's land mobile radio division too.

If you look at the photo and the specifications at the link the insertion loss is about 0.1db up to 500MHz for the example switch. That's only about 2.3 percent power loss, basically nothing to worry about.
https://diamondantenna.net/cx310a.html

Anderson Power Poles are commonly used. I have just about everything I use outfitted with them. There is sort of a semi official configuration for them. 
Anderson Powerpoles - Standard for ARES and RACES.pdf ARES - RACES Standard 12 VDC Power Connector.pdf INSERTION - EXTRACTION TOOL FOR PP15-45.pdf

You want a coax switch. Be sure you get one that is rated up pass the highest frequency you intend to use. Since you're stuck using SO-239 sockets on it you have to be careful to get the right insulator and socket design type.
Most SO-239 sockets for CB radio or HF work may use the crappy red or brown Bakelite insulating material around the center pin. DON'T use those!. These will cause SWR issues.
The better choice is when the material is white. That would typically be Delron or Teflon. While better than the above I would only recommend it for VHF and below.
The best is where the center pin is supported by what looks like a spoked wheel design around the center pin. That gives the interior of the socket mostly air and results in a socket impedance closer to 50 ohms, matching the radio and coax, which will mitigate SWR problems.
https://forums.mygmrs.com/gallery/image/431-coax-switchjpg/
 

If he does that it will may look OK from an SWR standpoint but the pattern will look bad with multiple lobes likely giving crummy coverage. I wouldn't recommend it other than as an experiment.

Rumor has it that Anytone is buying Motorola's land mobile radio division too.

Rumor has it that Anytone is buying Motorola's land mobile radio division too.

I get it.
The wife goes shopping. Sees an item that costs $2 but it's on sale for $1. So she buys it.
You go shopping. See the same item on sale. But you decide you don't need it.
Later you both can legitimately claim you "saved" a $1. The difference is you still have yours.

For a J-Pole type antenna a coax line choke at the base of the antenna is HIGHLY recommended.

And Midland filed for bankruptcy. Production and shipping of all models has been halted.

And Midland filed for bankruptcy. Production and shipping of all models has been halted.

They are. It depends are what point of view you take. The minimum length for a radiating element used as an antenna is 1/2 wavelength.  Obviously a 1/4 wave alone won't work. That's where the ground plane come into play. The easiest way to understand how it functions is place your finger at a right angle against a mirror. You see a reflection of your finger so it looks twice as long. The same thing happens with a ground plane. It "reflects" the 1/4wave element making it look like a 1/2 wavelength long.
By bending the radials it changes the feed point impedance so it's closer to 50 ohms, a good match to the 50 ohm coax cable. A true 1/2 wavelength dipole antenna is closer to 70 to 75 ohms with the feed point at the center. That results in an SWR of about 1.5:1, which is perfectly acceptable by just about any radio out there.
A 1/2 wavelength antenna is used where a ground plane, or room for radials at the base of a 1/4 wavelength antenna, is not possible. The draw back is the antenna is now twice as tall and the bandwidth is reduced since a special matching section is required at the base of the antenna.
Also high gain antennas are multiple sections of 1/4 and 1/2 wave elements with a "phasing" section in between the sections. Those are the small bulges or tiny single loops you see spaced along the length. The down side to high gain antennas is the gain is HIGHLY concentrated in a direction perpendicular to the antenna. Works great for relatively flat open terrain. Not so good in hills or mountainous areas. People who like to hit the trails often carry two antennas. A high gain one, these antennas can be rather tall, used when on the highway and a low gain, usually a 1/4 wavelength, when hitting the trails.
https://forums.mygmrs.com/gallery/image/259-ca-2x4mb-jeepjpg/?context=new
https://forums.mygmrs.com/gallery/image/268-ca-2x4sr/?context=new
https://forums.mygmrs.com/gallery/image/338-cheap-14-wave-gmrs-antenna/?context=new
 

They are. It depends are what point of view you take. The minimum length for a radiating element used as an antenna is 1/2 wavelength.  Obviously a 1/4 wave alone won't work. That's where the ground plane come into play. The easiest way to understand how it functions is place your finger at a right angle against a mirror. You see a reflection of your finger so it looks twice as long. The same thing happens with a ground plane. It "reflects" the 1/4wave element making it look like a 1/2 wavelength long.
By bending the radials it changes the feed point impedance so it's closer to 50 ohms, a good match to the 50 ohm coax cable. A true 1/2 wavelength dipole antenna is closer to 70 to 75 ohms with the feed point at the center. That results in an SWR of about 1.5:1, which is perfectly acceptable by just about any radio out there.
A 1/2 wavelength antenna is used where a ground plane, or room for radials at the base of a 1/4 wavelength antenna, is not possible. The draw back is the antenna is now twice as tall and the bandwidth is reduced since a special matching section is required at the base of the antenna.
Also high gain antennas are multiple sections of 1/4 and 1/2 wave elements with a "phasing" section in between the sections. Those are the small bulges or tiny single loops you see spaced along the length. The down side to high gain antennas is the gain is HIGHLY concentrated in a direction perpendicular to the antenna. Works great for relatively flat open terrain. Not so good in hills or mountainous areas. People who like to hit the trails often carry two antennas. A high gain one, these antennas can be rather tall, used when on the highway and a low gain, usually a 1/4 wavelength, when hitting the trails.
https://forums.mygmrs.com/gallery/image/259-ca-2x4mb-jeepjpg/?context=new
https://forums.mygmrs.com/gallery/image/268-ca-2x4sr/?context=new
https://forums.mygmrs.com/gallery/image/338-cheap-14-wave-gmrs-antenna/?context=new
 

They are. It depends are what point of view you take. The minimum length for a radiating element used as an antenna is 1/2 wavelength.  Obviously a 1/4 wave alone won't work. That's where the ground plane come into play. The easiest way to understand how it functions is place your finger at a right angle against a mirror. You see a reflection of your finger so it looks twice as long. The same thing happens with a ground plane. It "reflects" the 1/4wave element making it look like a 1/2 wavelength long.
By bending the radials it changes the feed point impedance so it's closer to 50 ohms, a good match to the 50 ohm coax cable. A true 1/2 wavelength dipole antenna is closer to 70 to 75 ohms with the feed point at the center. That results in an SWR of about 1.5:1, which is perfectly acceptable by just about any radio out there.
A 1/2 wavelength antenna is used where a ground plane, or room for radials at the base of a 1/4 wavelength antenna, is not possible. The draw back is the antenna is now twice as tall and the bandwidth is reduced since a special matching section is required at the base of the antenna.
Also high gain antennas are multiple sections of 1/4 and 1/2 wave elements with a "phasing" section in between the sections. Those are the small bulges or tiny single loops you see spaced along the length. The down side to high gain antennas is the gain is HIGHLY concentrated in a direction perpendicular to the antenna. Works great for relatively flat open terrain. Not so good in hills or mountainous areas. People who like to hit the trails often carry two antennas. A high gain one, these antennas can be rather tall, used when on the highway and a low gain, usually a 1/4 wavelength, when hitting the trails.
https://forums.mygmrs.com/gallery/image/259-ca-2x4mb-jeepjpg/?context=new
https://forums.mygmrs.com/gallery/image/268-ca-2x4sr/?context=new
https://forums.mygmrs.com/gallery/image/338-cheap-14-wave-gmrs-antenna/?context=new