TD-H3 GMRS observation: transmit issue with/without privacy code

[Imply4907]

Good day!

I apologize if this question has been asked/answered -- I did some searching and wasn't able to find anything specific to this, yet I don't believe I'm the first person to encounter this.

TLDR; I can't transmit on a second similar frequency channel with or without a "privacy code"

I know "privacy code" usage isn't private. I'm using it as a general term for using DCS/CTCSS codes to reduce hearing unwanted signals.

Equipment: I have a TIDRADIO TD-H3 (HAM version) running in GMRS mode

• The firmware version is GMRS_240817
• I can and have programmed it on Odmaster or CHIRP
• I can do some limited work on the HT itself
• I just got it this week, so I'm still a little new (Jan. 15 2025)

Intent: My younger children have some FRS radios where I used FRS/GMRS Channel 1 plus a "privacy code" to (a) reduce some of the distraction from area GMRS/FRS users (b) potentially reduce the possibility that their ears might hear something inappropriate. I'd still like to be able to switch to a regular "privacy code"-free channel when I'm away.
I want to talk to communicate with them from my TD-H3.

Situation: I can't transmit out on higher of the TD-HD3's two channels if I have a mixture of privacy code and non-privacy code for the same frequency. The radio prevents transmitting on the higher channel of the same simplex frequency. Example: If I use GMRS freq. 1 and put the "privacy code" on HT radio channel 1. I then use a "privacy code" free GMRS freq. 1 on the HT radio's channel/slot 100. I can transmit out and be heard on the FRS radio when I use HT slot 1, but can't actually transmit (and hear a rejection tone) when I use the HT radios slot 100 on the same frequency. If I make HT slot 1 clear of codes and make HT slot 100 the same frequency as channel 1, but use a "privacy code", the radio blocked me from transmitting on slot 100.

I discovered this after several hours of troubleshooting and hand-wringing. It didn't matter whether I used DCS or CTCSS. I then tried using "privacy code" on the lower radio channel and put the privacy free* on the greater channel and saw I could use a privacy code successfully. What's a little weird is that I have a repeater setup with a CT tone and the radio will transmit fine.

I don't know if this is by design or a limitation of the TD-H3 and similar firmware. For all I know, it might be a general phenomenon of TIDRADIO products.

Comparison: I have a brand new pair of Baofeng 5RMs that I would like to see if they exhibit the same phenomenon, but there are issues with the programming over the cable preventing me from quickly programming them. Maybe I'll figure out how to program them on the keypad. Observation: I get the feeling that Baofeng and TIDRADIO are basically the same manufacturer but simply different brands.

Kind regards,

Jim
Woodleaf, NC USA
WSGP797

Edited January 25 by Imply4907
clarification of the "intent" section. Edit 2: improved title. Edit 3: Corrected typo in firmware version. Edit 4: standardized language from radio channel to radio slot and used slot 100 rather than 31

[SteveShannon]

1 minute ago, Imply4907 said:

That's pretty succinct, @SteveShannon. thanks

 

Instead of “work” I would say “transmit”, if that’s accurate. “Won’t work” doesn’t provide enough information. 

[Imply4907]

On 1/22/2025 at 3:41 PM, LeoG said:

CH31 is a repeater frequency which will transmit at 467.xxx frequency and receive on 462.xxx frequency.  You need to limit yourself to the lower 22 channels to stay in simplex, TX/RX on the same frequency..

Oh gosh! So I used CHIRP and it programmed the frequencies wrong on the radio! I figured I'd use CHIRP since it's a bit deeper. I attached pictures.

 

I read the radio, inserted a line at slot 22, copied slot 1 (GMRS ch. 1) to empty slot 22. Then I changed the name and added the tone. Wrote back to the radio (I didn't save the image). I noticed I could transmit on 22, but I also noticed that the frequencies didn't go in the way I programmed them.

I am on a pretty new version of CHIRP (not the bleeding edge) but not more than 2 weeks old.

[Imply4907]

I see people install alternate firmware on H3's. Maybe I should consider it? I don't know. I'm pretty new with these radios (not software and firmware, though).

[Imply4907]

2 hours ago, LeoG said:

I think the H3 has a limitation that you can only transmit on the 1st 54 programmable channels.  After 54 they are receive only.

@LeoG, that might have been the issue. I may have overlooked it in the owner’s manual about the transmit channel slot limitation. I will have to find it and confirm. But I was able to program GMRS 1 on slot 43 on the keypad with some CTCSS tones and it appeared to transmit. I’m out on the road and can’t test thoroughly. Thank you for the tip.

[RIPPER238]

9 hours ago, LeoG said:

I think the H3 has a limitation that you can only transmit on the 1st 54 programmable channels.  After 54 they are receive only.

I have no issues transmitting on higher channels. 185 for example, no issue. GMRS version unlocked. 

[RIPPER238]

15 hours ago, LeoG said:

Maybe they fixed it since version 702

Limitation of the machine. lol

Maybe? Technically I transmitted on CH185 on ~2M. Haven't tried GMRS that high. 

[LeoG]

And using the APP from Tidradio I was also not able to program any transmit frequencies into channel 55, I assume and up even though I didn't try.

I have AM stationed programmed into the radio and the APP won't read those from memory either.  If I write back I lose my AM stations (Airport).

[Imply4907]

On 1/26/2025 at 2:26 PM, SteveShannon said:

@Imply4907 Is your radio unlocked?

@SteveShannon By "unlocked", if you mean "Normal" mode, then "no". I am using GMRS mode. But I did find that it worked if I used a slot between 31 and 54. I think I used 42. Hallelujah!

[Imply4907]

On 1/27/2025 at 3:15 AM, TrikeRadio said:

the RX only above channel slot 54 applies only when the radio is operating in GMRS mode.
if you are in the unlocked "Normal" mode... there are no restrictions.

I am not sure if there are any similar restrictions in HAM mode.

@TrikeRadio Eventually, when I get my AR license I'll try it. Right now I restrict myself to GMRS. I truly appreciate the help and suggestions. I ended up sending back the U5R's and buying two more TD-H3 "GMRS" models for other people in the family. The only thing I don't really like about the "H3" is that when dropped, the battery comes off rather easily. I think for the price and size, the 2408__ software is decent. I see someone saw newer firmware. I'll have to check out the features and bug fixes and decide whether I want to re-image the EPROM.

[LeoG]

4 minutes ago, Imply4907 said:

@TrikeRadio Eventually, when I get my AR license I'll try it. Right now I restrict myself to GMRS. I truly appreciate the help and suggestions. I ended up sending back the U5R's and buying two more TD-H3 "GMRS" models for other people in the family. The only thing I don't really like about the "H3" is that when dropped, the battery comes off rather easily. I think for the price and size, the 2408__ software is decent. I see someone saw newer firmware. I'll have to check out the features and bug fixes and decide whether I want to re-image the EPROM.

Don't drop it then.