OffRoaderX

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My DB40-G did not come with a programming cable.  Has anyone purchased a DB40-G and if so did yours come with the cable?  And, what type of cable is it?

If your UV-82 is locked, which it sounds like it is, it will not transmit on GMRS frequencies (or any non-H.A.M. frequencies), and yes, it can still receive and listen to those frequenices.  If your UV-82 is not locked, then it will also transmit on GMRS and other non-H.A.M. frequencies.
The DB20G is a mobile GMRS radio so of the box it will transmit on all of the standard GMRS channels EXCEPT for channels 8-14, so because channel 7 is not between 8 and 14, it should also transmit on channel 7. If it does not, then you are either doing it wrong, you screwed up the programming, or its defective - and i doubt it is defective.

ANY hand-held GMRS radio will talk back and forth with FRS radios.  Any mobile GMRS radio will talk back and forth with FRS radios on channels 1-7 and channels 15-22 .

If the FCC doesn't even care (based on their contacts/enforcements), then why would I care?

The FCC ID on my GMRS version is:  2A4F8TD831G

If the FCC doesn't even care (based on their contacts/enforcements), then why would I care?

If the FCC doesn't even care (based on their contacts/enforcements), then why would I care?

I left my goat rope at your mom's house..

Sorry, this is a little long.  Hopefully not TL;DR long.
This is somewhat Emergency Communications related, but will hopefully answer some questions a lot of new people have about needing a duplexer for a repeater.  I have to say that you need a duplexer if you want to use one antenna.  There is no way around that.  However, you can run a repeater with two antennas if you have the physical space to work with.


 
I have been playing with repeaters for some time.  I have never run a duplexer with any of my repeaters, but rather using two antennas physically separated horizontally.  This is because most of my repeaters are intended to be used in the field during an EmComm event.  So, rather than re-tuning a duplexer while trying to resolve frequency coordination issues in the field, we can simply pick our new frequency pair and carry on.


 
I never really had any desense issues, because I have historically been using two cross-band repeaters, occasionally with as much as 1,000 feet of physical separation and simply RF-linked the two systems.  The space between the two systems resolved any desense issues through natural atmospheric attenuation.  


 
This weekend, I tried doing some testing to see how vertical separation would work, with both antennas on the same mast.  Based on advice from several reliable techs and engineers in the commercial RF world, I figured I would give it a shot.  Unfortunately, my results were not as good as what my research implied it would be.


 
The idea behind stacking the transmit and receive antennas is that there are nulls above and below the axis of the antennas. The more separation, the wider the null in the field gets and the more attenuation you get.  My problem is, with a portable mast, I can’t separate them enough.  I tried clocking the antennas on the mast and had no change in performance worth mentioning, regardless of where they were. 


 
First, only using 5w on 145 Mhz, I stack the receive antenna on the mid-section of the mast and the transmit antenna on the top of the mast.  Both antennas have ground plans.  The initial separation was 40 inches.  The transmitter was splashing the receiver with -4dBm / 0.14 volts.  I moved them to 80 inches apart and it dropped to -57dBm… still not great at an additional 17 dB of attenuation.  Finally, I moved the antennas to 360 inches, a full 30 feet apart.  The splash only dropped to -74dBm, about an additional 23dB compared to 40 inches.


 
As a quick note, I was using LMR400 cable for both antennas.  Swapping the antenna positions made it so the repeater was completely unusable.


 
The next test was using horizontal separation but wired instead of RF linking.  I put the two masts up at 35 feet with the antennas at the top, and same elevation.  The masts were only 130 feet apart from each other.  I placed the repeater in between the two masts for general testing.


 
Testing in this configuration showed that at 20w the transmitter was splashing the receiver at -120dBm… a shade over 38dB of attenuation compared to stacking the antennas at 40 inches of separation and almost 47dB of atmospheric attenuation in total.  At 5w, it was attenuated to the degree that splash was no longer measurable on my SA at the offset frequency.  This is pretty good for what it is, as my repeater’s receive sensitivity is 0.2uv / -121dBm.  This means that at 20w the transmitter is preventing only the very weakest of signals that the repeater could possibly hear from actually being heard.


 
The cable I am using has a loss of 1.5dB per/100’ on 150 MHz.  So, I could increase the physical separation to 340 feet (two 200 foot cables on each feed) and still get 50% of my power to the transmit antenna.  Or, I could set the repeater off-center, closer to the receive antenna to minimize line loss on the receive side, turn the power up to 50W on the transmit side and still have plenty of natural atmospheric attenuation for good performance. 


 
I haven’t performed any testing on the UHF spectrum yet.  However, you need less space for UHF than VHF.  I would suspect that you would see at least another 10dB of attenuation at the distance I tested (130’) or the antennas could be placed as little as 40 feet apart with similar performance.  I will be testing again on 440 MHz, possibly on Thursday.  So, I should be able to confirm.


 
Obviously, having the transmitter and receiver tied together with cables will not provide the low loss and optimal atmospheric attenuation that can be obtained with split-band RF linked systems, but it reduces the amount of hardware you need for radios, power sources and physical security.  As long as you have the 200 feet to separate your two antennas, you should be fine.

I did this, and every radio I have shows phenomenal SWR readings

If your UV-82 is locked, which it sounds like it is, it will not transmit on GMRS frequencies (or any non-H.A.M. frequencies), and yes, it can still receive and listen to those frequenices.  If your UV-82 is not locked, then it will also transmit on GMRS and other non-H.A.M. frequencies.
The DB20G is a mobile GMRS radio so of the box it will transmit on all of the standard GMRS channels EXCEPT for channels 8-14, so because channel 7 is not between 8 and 14, it should also transmit on channel 7. If it does not, then you are either doing it wrong, you screwed up the programming, or its defective - and i doubt it is defective.

ANY hand-held GMRS radio will talk back and forth with FRS radios.  Any mobile GMRS radio will talk back and forth with FRS radios on channels 1-7 and channels 15-22 .

The UV-82 is a ham radio, so it will not transmit on GMRS frequencies.. To fix this, buy a GMRS radio OR buy a radio that can be 'unlocked' to transmit outside of the intended frequency range.

The DB20G is a GMRS mobile radio and per the FCCs rules, only hand-held GMRS radios my transmit on channels 8-14, however the DB20G should transmit on channel 7, so you may want to re-check that one.

If your UV-82 is locked, which it sounds like it is, it will not transmit on GMRS frequencies (or any non-H.A.M. frequencies), and yes, it can still receive and listen to those frequenices.  If your UV-82 is not locked, then it will also transmit on GMRS and other non-H.A.M. frequencies.
The DB20G is a mobile GMRS radio so of the box it will transmit on all of the standard GMRS channels EXCEPT for channels 8-14, so because channel 7 is not between 8 and 14, it should also transmit on channel 7. If it does not, then you are either doing it wrong, you screwed up the programming, or its defective - and i doubt it is defective.

ANY hand-held GMRS radio will talk back and forth with FRS radios.  Any mobile GMRS radio will talk back and forth with FRS radios on channels 1-7 and channels 15-22 .

The UV-82 is a ham radio, so it will not transmit on GMRS frequencies.. To fix this, buy a GMRS radio OR buy a radio that can be 'unlocked' to transmit outside of the intended frequency range.

The DB20G is a GMRS mobile radio and per the FCCs rules, only hand-held GMRS radios my transmit on channels 8-14, however the DB20G should transmit on channel 7, so you may want to re-check that one.

You have made it abundantly clear, many times, in many posts, that there are many things you cannot understand.

I used the USB-C Port on the radio (not on the battery) and i could not get it to work with one of my own USB-C cables, only with the cable that came with it.

Welcome to the forum, but, if you are using GMRS to find new friends you have chosen the wrong hobby. GMRS is more for communicating with existing friends while driving, hiking, etc.  For finding new friends/talking to strangers, ham radio or the Grindr app might be a better choice.

You have made it abundantly clear, many times, in many posts, that there are many things you cannot understand.

You have made it abundantly clear, many times, in many posts, that there are many things you cannot understand.

You have made it abundantly clear, many times, in many posts, that there are many things you cannot understand.

You have made it abundantly clear, many times, in many posts, that there are many things you cannot understand.

I have a hammer and a butter-knife, I can take anything apart.

Yes.

If you are inferring that the radio cannot be programmed via the keypad, you would be wrong. 
You are also wrong about it not being much different from any other radio..
But other than that, you're 100% right.

I heard a rumor that the self-inflicted Queen Of All That Is GMRS has had one for a few months and really likes it, and will be making a video about it on the same day that Midland officially makes it available for purchase.
But you know, thats just a rumor.