Hasaf

I recently installed an AT-778 in my FJ Cruiser, as you can see, it has all of the controls on the mic.

I recently installed an AT-778 in my FJ Cruiser, as you can see, it has all of the controls on the mic.

I think a good part of the issue, at least for me, is that there are no APRS facilities near me. As such, I can only see if I got it working when I go on a long drive.

The factory most likely tests their antennas with a laboratory grade VNA.

Here is a photo I just took using a calibrated NanoVNA to check one of my 144-520MHz HT antennas. Not bad at all.

I can tell you that the results changed, but insignificantly, between holding the VNA vertical, horizontal, standing it on a table, laying it flat on a wooden table, laying it flat on wooden table with the antenna overhanging the edge of the table, and when touching and not touching the chassis ground of the VNA.

When comparing HT antenna performance, the best comparison of antennas is not going to be it’s SWR, but relative difference in signal strength at some given far field distance using some given amount of input power.


Michael
WRHS965
KE8PLM

Here are the antennas. GMRS in the centre rear, VHF/UHF in the centre front, CB (11M) in the left rear by the hinges.

 

The most official designation of frequencies as channel numbers that I have every found comes from here:

§ 95.563 FRS channels.

The FRS is allotted 22 channels, each having a channel bandwidth of 12.5 kHz. All of the FRS channels are also allotted to the General Mobile Radio Service (GMRS) on a shared basis. The FRS channel center frequencies are set forth in the following table:

1 ................................................ 462.5625 2 ................................................ 462.5875 3 ................................................ 462.6125 4 ................................................ 462.6375 5 ................................................ 462.6625 6 ................................................ 462.6875 7 ................................................ 462.7125 8 ................................................ 467.5625 9 ................................................ 467.5875 10 .............................................. 467.6125 11 .............................................. 467.6375 12 .............................................. 467.6625 13 .............................................. 467.6875 14 .............................................. 467.7125 15 .............................................. 462.5500 16 .............................................. 462.5750 17 .............................................. 462.6000 18 .............................................. 462.6250 19 .............................................. 462.6500 20 .............................................. 462.6750 21 .............................................. 462.7000 22 .............................................. 462.7250

And here

https://apps.fcc.gov/kdb/GetAttachment.html?id=biZxuanIfZOUqdjvLHdsyw%3D%3D&desc=888861%20D01%20Part%2095%20GMRS%20FRS%20v01&tracking_number=239603

https://www.law.cornell.edu/cfr/text/47/95.563

Although within part 95e, standard channel number are not defined as they are in the FRS, it does seem logical that since they are defined for FRS and both services share 22 of the same frequencies that there is a logical numeric correlation that can (as has) been made between the two.


Michael
WRHS965
KE8PLM

For what it's worth, this is what the RR wiki has to say about it in two places:

https://wiki.radioreference.com/index.php/Family_Radio_Service#Recognized_Channels



https://wiki.radioreference.com/index.php/General_Mobile_Radio_Service#Recognized_Channel_Usage


Beats me if there is actual general adoption of any of the above, as GMRS is typically just casual/local type comms for caravans and families in most situations, as many have pointed out.
Interesting thread though!

I don't know why some are trying to reinvent the wheel 

It is a switch.
That is what I have done, both it and the 2m/440 are wired to a relay after the accessory circuit. As such, they turn on and off with the car. As for the switch on the radio, I just leave it on.