Radiodditty DB20-G Programming Issue

[WROG611]

I have a DB20-G and I programmed a series of simplex channels (14-22) with various different CTTSS/DCS code to change channel on the fly when I travel with a friend who has the same channels programmed into his radio.  I gave each channel a unique name.    They are in channel positions 31 to 54 and in channels 55 and 56 I programmed a couple of repeaters.  Those programmed into channels 31 to 39 work as they should and anything programmed into channels of 40 and above do not transmit and I get an error tone.   Now when I take a channel setup from say channel 44 and put it in channel 32 it works as it should.   It appears that anything programmed in channel positions below 40 work and above 40 don't. Any idea what is the cause of the problem.   I included a copy of my .dat file if you think that would help.

BACKUP db20g .dat

[MichaelLAX]

My recollection is that when it is in the "GMRS" mode that comes from the factory, there are only a limited number of programming channels that will allow alternate CTCSS and/or DCS tones and still transmit:

Channels 1-22 can only transmit simplex; 

Channels 23-40 can only transmit with the +5 MHz offset already factory set (so not simplex).

Channels 41 through 500 cannot transmit.

If you do this, you can "open your DB-20G" to transmit as you want to program (remember the FCC rules for frequency and power output as well as narrow vs. wideband), as well as find out your firmware version:

Turn off

Hold down V/M key

Turn on

Write down Firmware version listed on the bottom line.

If you want to "open" your DB-20G, do this:

Using the Up and Down Keys, change the Mode from GMRS to:

(136-174)

(400-470)

Now turn off.

-----------------------------------

You can also accomplish this in the Radioddity programming software by clicking Model -> Model Information:

[wayoverthere]

51 minutes ago, WROG611 said:

I have a DB20-G and I programmed a series of simplex channels (14-22) with various different CTTSS/DCS code to change channel on the fly when I travel with a friend who has the same channels programmed into his radio.  I gave each channel a unique name.    They are in channel positions 31 to 54 and in channels 55 and 56 I programmed a couple of repeaters.  Those programmed into channels 31 to 39 work as they should and anything programmed into channels of 40 and above do not transmit and I get an error tone.   Now when I take a channel setup from say channel 44 and put it in channel 32 it works as it should.   It appears that anything programmed in channel positions below 40 work and above 40 don't. Any idea what is the cause of the problem.   I included a copy of my .dat file if you think that would help.

BACKUP db20g .dat 16.97 kB · 0 downloads

I'm inclined to think firmware bug, honestly, but I'm open to other ideas. 

I took a look at the dat file (I have the Anytone cousin, but use the Radioddity software to program mine too, and nothing stood out as the culprit in the configuration.  I do notice that the option in the channel settings window to disable TX is greyed out, which I suspect is part of the GMRS configuration. I have one of mine opened up for ham use, and that option is definitely available in that configuration..if I have a chance later, I'll grab the radio out of the car and try it in GMRS guise and see if that option shows up.  If it's still there, that would make me lean even further toward a firmware issue.

Perhaps @MichaelLAXmay have some ideas?  You may also reach out to Radioddity to see if there's an update needed to the firmware...from what I've read, they're reasonably open to fixing such things, and solid on support.

[WROZ250]

I

Sorry, didn't see the reply by @MichaelLAX Follow his procedure.

It's not a bug.  By default, there are a finite amount of memories that permit transmit in the GMRS mode.

Do yourself a favor.  With the radio off, press and hold V/M button and power the radio on.  You will get a menu of configurations/frequency ranges.  If you select the 400-480 range (or whatever roughly matches that) the radio will revert to that setup and all memories are usable for TX/RX.  Your existing memories will be reset to new defaults, but assuming you only want GMRS, you now have as many usable memories as the radio offers.

The same is true for the AT-779UV and other clones of that radio.

FWIW, this 'mod' is completely reversible, at least it was for all of my radios.

[wayoverthere]

12 minutes ago, MichaelLAX said:

My recollection is that when it is in the "GMRS" mode that comes from the factory, there are only a limited number of programming channels that will allow alternate CTCSS and/or DCS tones and still transmit.

 

9 minutes ago, WROZ250 said:

It's not a bug.  By default, there are a finite amount of memories that permit transmit in the GMRS mode.
 

Good catch, both. Thank you for filling in the details...I clearly haven't used mine under gmrs mode enough.

[WROG611]

Thank you to all for the quick responses.  Now I know what I have to do.  Regarding Radioddity Support at the same time as I posted this I sent them an email with the same question and here is the answer I received.

Thanks for reaching out to Radioddity Support! I am Leslie and I'd be happy to assist you with this.

Please kindly notice that the channels over 39 in DB20-G are receive-only channels, which can not be programmed as TX channels. That is why the radio has an error tone.

Here I attach the 500 Channels Table of DB20-G for your reference:

Channel 1-30 (RX and TX): 30 GMRS channels

Channel 31-39 (RX and TX): 9 DIY repeater channels

Channel 40-493 (RX only): 454 VHF(136-174MHz) and UHF(400-490MHz) channels

Channel 494-500 (RX only) 7 NOAA Channels

Please feel free to let me know if you need any further assistance or information.

 

[MichaelLAX]

Open the sucker and get 500 transmissible Channels!! 

[WRYY390]

I found this thread via a search-- I have the same radio with same issue. My issue popped when I was trying to add in ALL the repeaters in my area which worked fine until I got to CH-40. The solution shown here seems great for GMRS but I also have some channels programmed to receive the five MURS channels.  I bought a Browning antenna that I tuned to an SWR of 1.01-1.2 over GMRS freq's . If I open up the radio to transmit on all channels will I run risk of damaging radio if I inadvertently hit the PTT while on a MURS channel?( I'm aware this is also against FCC rules) I'm sure the SWR in the MURS range(150-155) would be sky high. 

Thanks..

Edited January 19 by WRYY390
Never Mind I answered my own question and saw that you can disable transmit in software

[SteveShannon]

25 minutes ago, WRYY390 said:

I found this thread via a search-- I have the same radio with same issue. My issue popped when I was trying to add in ALL the repeaters in my area which worked fine until I got to CH-40. The solution shown here seems great for GMRS but I also have some channels programmed to receive the five MURS channels.  I bought a Browning antenna that I tuned to an SWR of 1.01-1.2 over GMRS freq's . If I open up the radio to transmit on all channels will I run risk of damaging radio if I inadvertently hit the PTT while on a MURS channel?( I'm aware this is also against FCC rules) I'm sure the SWR in the MURS range(150-155) would be sky high. 

Thanks..

Most modern transceivers are capable of reducing their power if they detect that they are transmitting into a high SWR load, so an accidental brief PTT probably wouldn’t damage your radio.  I have the same radio and I definitely have transmitted into a high SWR antenna.  Once I realized my mistake I repaired the antenna and there doesn’t seem to be any damage. 

Steve

[WRUU653]

21 minutes ago, Sshannon said:

Most modern transceivers are capable of reducing their power if they detect that they are transmitting into a high SWR load, so an accidental brief PTT probably wouldn’t damage your radio.  I have the same radio and I definitely have transmitted into a high SWR antenna.  Once I realized my mistake I repaired the antenna and there doesn’t seem to be any damage. 

Steve

Steve, I didn't realize that some radios did this, makes good since though. Not having this radio (yet, haven't stopped collecting) but I was wondering if the programming allows you to preset power levels for individual channels or do you change all via the face. Obviously this doesn't help the antenna tunning issue but I was thinking this could also help in @WRYY390's set up but I am unsure. 

[SteveShannon]

1 hour ago, WRUU653 said:

Steve, I didn't realize that some radios did this, makes good since though. Not having this radio (yet, haven't stopped collecting) but I was wondering if the programming allows you to preset power levels for individual channels or do you change all via the face. Obviously this doesn't help the antenna tunning issue but I was thinking this could also help in @WRYY390's set up but I am unsure. 

I programmed one of mine (which I use for ham radio) using the software, but I don’t remember for certain whether power output can be configured on a per channel basis. I’m thinking it must be in order to accommodate the different power outputs for different frequencies in GMRS. 
That would definitely be a good idea. MURS is limited to low power anyway. You don’t want to get on there at 20 watts.

[WRUU653]

2 hours ago, Sshannon said:

MURS is limited to low power anyway. You don’t want to get on there at 20 watts

That was kind of what I was thinking. 

[WRYS709]

5 hours ago, WRYY390 said:

I found this thread via a search-- I have the same radio with same issue. My issue popped when I was trying to add in ALL the repeaters in my area which worked fine until I got to CH-40. The solution shown here seems great for GMRS but I also have some channels programmed to receive the five MURS channels.  I bought a Browning antenna that I tuned to an SWR of 1.01-1.2 over GMRS freq's . If I open up the radio to transmit on all channels will I run risk of damaging radio if I inadvertently hit the PTT while on a MURS channel?( I'm aware this is also against FCC rules) I'm sure the SWR in the MURS range(150-155) would be sky high. 

Thanks..

You can use the programming software to turn off transmission channel by channel if that is your fear.

Somewhere on this Forum, I posted my GMRS codeplug for once the radio is open to transmit on all 500 frequencies, to keep it within Part 95E rules, other than the fact that it probably loses its certification once opened.

It might be posted on an Anytone AT-779UV thread, as that is the same radio.