Midland present channels: Won't talk to GMRS

[fremont]

Hi, first time poster.  

 

Took my Midland FRS GXT-1000P and tried twice with its "preset channels" (23-50) to talk to my BTech GMRS-V1 using both CTCSS and DCS.  I programmed my BTech with what Midland told me to do (using same code for both Rx and Tx per BTech's instructions) and nothing.  Devices work fine without privacy codes when in channels 22 and below.

 

Apologies if this has been covered previously and/or multiple times before.  And, yes, as one website suggested, I tried it with privacy codes 38 and under.

[tweiss3]

This is because channels 1-22 are the SIMPLEX channels, meaning they go straight from device to device. For example, looking at Channel 15, it transmits on 462.55 and receives on 462.55.

 

Channels 23+ are your REPEATER channels, meaning, they are designed to transmit on a frequency 5MHz higher than they receive. Channel 23 is also know as Repeater Channel 15 (sometimes Repeater 550). It transmits on 467.55 and receives on 462.55. Your Midland device is looking for a signal on 462.55 while your Btech is transmitting on 467.55. The same happens the other way around, when the Btech is transmitting and the Midland is listening.

 

These repeater channels are designed to be transmitted to a third piece of equipment called a REPEATER which then re-transmits the signal for all to hear on the frequency 5MHz below. See the below visualization on how it works from HamRadioSchool: https://hamradioschool.com/simplex-duplex-offset-and-split/#:~:text=If%20you%20are%20talking%20to,and%20the%20repeater%20transmit%20frequency.&text=Repeaters%20operate%20in%20full%20duplex,transmit%20at%20the%20same%20time.

NOTE: The frequencies noted are VHF, not GMRS, but get the idea across.

[kidphc]

Those extra channels on the Midland are bit of bs. They basically are the regular channels set with tones.

 

https://www.buytwowayradios.com/blog/2008/05/how_midlands_extra_channels_work.html

 

Make sure the btech is set the same. Plus past channel 30 on the BTech settings won't be saved.

[nvrocketeer]

This is because channels 1-22 are the SIMPLEX channels, meaning they go straight from device to device. For example, looking at Channel 15, it transmits on 462.55 and receives on 462.55.

 

Channels 23+ are your REPEATER channels, meaning, they are designed to transmit on a frequency 5MHz higher than they receive. ....

 

Sorry, but no. On the GXT1000 series, ch 15-22 are the 462 MHz main frequencies, 1-7 are the 462 MHz interstitial frequencies, and 8-14 are the low-power 467 MHz interstitial frequencies. You've correctly identified ch 15, but the rest is misleading and does not work toward the problem.

 

As a later poster noted, Midland's "Ch 23-50" are just a hard-coded selection of regular channels with CTCSS or DCS tones applied. A delusionary shortcut which lets them claim "50 channels!" when it's not, not really. These radios do not support the 467 MHz main frequencies which tie to the repeater options.

 

Page 18 of the GXT radio user manual lists all the permutations. But I don't know if CTCSS or DCS definitions are common between manufacturers. So I'll be happy to take education in that regard. (Insert the forum-required "privacy codes aren't actually private" disclaimer here.)

 

Hope that helps,

Bob P

[fremont]

Thanks to all those trying to help me.  

 

Short story was that I was able to get my BTech GMRS-V1 to speak to my Midland GXT1000P on one of the "present channels" (e.g., privacy codes); it was between Midland channel 31 and GMRS channel 2 using DCS 1 (D023N).

 

I tried on three other setups (per Midland's instructions) with no success, although, on at least two attempts, the Midland would light up and show "RX" but without sound when transmitting from the BTech.

 

Apologies for the poor photography.

 

 

 

[fremont]

Those extra channels on the Midland are bit of bs. They basically are the regular channels set with tones.

 

https://www.buytwowayradios.com/blog/2008/05/how_midlands_extra_channels_work.html

 

Make sure the btech is set the same. Plus past channel 30 on the BTech settings won't be saved.

Thanks for posting this; I saw it yesterday.  Per "Danny's" advice, I tried and stay below "extra channel" 38--still couldn't always make it work the majority of the time.

[nvrocketeer]

I'm kinda glad to see I'm not the only one who writes on my Page 18. 

 

Speaking of that page ... weather radio frequencies. Every manufacturer seems to want to put different frequencies on different channel numbers. I had to make a score-card...

[tweiss3]

Your problem might be Midland is narrowband and the Btech can be either. Connect it to CHIRP and you can flip them all over to FMN, you might then get better decoding of the DCS tone then. Narrowband can sound "soft" on a wideband receive and might not be loud enough to decode.

[Ccleveland1226]

I have the same model handhelds so I tried to recreate the same issue on my radios last night. Mine won't play nice with each other either when using Dcs tones. I plan on messing around with them some more to see if I can figure it out, but if you find the solution let me know.

[wayoverthere]

Haven't had a chance to compare the book to this chart (to see if any of it differs) but I stumbled across this while looking for something else.

 

https://www.buytwowayradios.com/blog/2008/05/how_midlands_extra_channels_work.html

[fremont]

Haven't had a chance to compare the book to this chart (to see if any of it differs) but I stumbled across this while looking for something else.

 

https://www.buytwowayradios.com/blog/2008/05/how_midlands_extra_channels_work.html

Thanks for posting this; now I'm really confused.  On at least one CTCSS code (#29) that I've unsuccessfully tried in the past (getting my GMRS-V1 to talk to my FRS GXT1000P), there are three different tones:  1) My BTech manual (165.5); 2) the chart wayoverthere provided (179.5); and the Kenwood chart below (173.8). 

 

Why are they different across manufacturers?

 

Well, at least I've got a few more things to try in getting those two handhelds to communicate in "privacy" mode.

 

[wayoverthere]

Why are they different across manufacturers?

Trying to encourage us to stick with one brand? Midland insisting on doing it their way all the way?

 

It appears the gmrs-v1 has the option for scan for ctcss/DC's codes (on pg 40 of the manual here:https://baofengtech.com/usermanual/gmrs-v1-manual.pdf )...maybe that will catch them once and for all?

 

I may try to poke at the codes a bit at well, I have the gxt1000's and the wouxun up top.

[fremont]

It appears the gmrs-v1 has the option for scan for ctcss/DC's codes (on pg 40 of the manual here:https://baofengtech.com/usermanual/gmrs-v1-manual.pdf )

 

After reading manual Pg 40 (more than once), the example it gave was pulling the tone from another transmitter which already had access to a repeater you're interested in using (by scanning that repeater's input frequency).  I'm not clear how it would pull a tone from a Midland FRS turned to a preset channel, e.g., Channel 30 462.7000 (which is GMRS 21).

[wayoverthere]

After reading manual Pg 40 (more than once), the example it gave was pulling the tone from another transmitter which already had access to a repeater you're interested in using (by scanning that repeater's input frequency).  I'm not clear how it would pull a tone from a Midland FRS turned to a preset channel, e.g., Channel 30 462.7000 (which is GMRS 21).

i'm not 100% clear it will do it, but maybe worth a try (i may give it a try too, as i'm pretty sure at least one of my baofeng HTs have that capability, but to stay kosher i'll use the wouxun to test transmitting back to the midland  

 

i don't think it should make a different whether it's listening to another transmitter talking to a repeater, or just a transmitter talking into the ether, as in either case it's just listening to a signal for the tone.

 

edit to add: poked at it a little right now, ch 31 on the midland, ch 2 on the wouxun, with DCS D023N, is a successful read on the midland. also good on ch 29 on the midland, 19 on the wouxun, CTCSS 131.8, also a success.

 

one thing i see in the numbering differences between charts is that midland skips a few of the ctcss codes (doesn't do 69.3, for example). it's kind of a pain, but so far it's been using midland's chart to see what normal channel their special channel equates to, then taking the code to their code charts to see what that translates to in normal radio speak.

[fremont]

Well, I think I may have solved the mystery:  When I solely use the CTCSS/DCS codes within the Midland manual (vs. what I did which was use what was in my BTech V1 manual), it seems to work.  At least the CTCSS codes certainly don't always match between the two.  I am surprised there is a difference, but, at least, now I know.

[wayoverthere]

Well, I think I may have solved the mystery: When I solely use the CTCSS/DCS codes within the Midland manual (vs. what I did which was use what was in my BTech V1 manual), it seems to work. At least the CTCSS codes certainly don't always match between the two. I am surprised there is a difference, but, at least, now I know.

I think at least some of the difference related to the codes Midlands don't have, though I've yet to see a good answer as to WHY they left out some of the standard codes. BF and wouxun are at least good about adhering to the standard channels/codes.