BTECH GMRS-PRO 5W? I hear digital on scanner

[dkcorlfla]

Hi all, long story short is I upgraded the antenna and coax for my scanner and I'm now hearing digital on at least two GMRS channels. Sounds like it might be DMR but the emissions are mostly short. Might it be aprs and text? Ran some searches trying to find out what some of the new GMRS radios are using and ran across: BTECH GMRS-PRO 5W "Data over GMRS is silent."

Anybody have one of these radios? What does it sound like on a scanner?

Just curious and want to try and figure out the source of the DMR or DMR sounding data that I'm hearing.

Thanks, Dale

 

[Whiskey3JMC]

Do you have an audio sample you can post? If it were APRS it would sound something like this. If the data emissions happen at a regular interval every few seconds or so like this, you may have stumbled upon a CAP+ rest channel

 

[N4KVE]

Hi all, long story short is I upgraded the antenna and coax for my scanner and I'm now hearing digital on at least two GMRS channels. Sounds like it might be DMR but the emissions are mostly short. Might it be aprs and text? Ran some searches trying to find out what some of the new GMRS radios are using and ran across: BTECH GMRS-PRO 5W "Data over GMRS is silent."

Anybody have one of these radios? What does it sound like on a scanner?

Just curious and want to try and figure out the source of the DMR or DMR sounding data that I'm hearing.

Thanks, Dale

Probably your scanner with the better antenna, & coax is being overloaded, so you’re getting intermod. That’s what happened to me when I upgraded the antenna on Yaesu base scanner.

 

[Craigmoe]

Also, any digital mode on GMRS is not permitted legally.
Looked at this BTECH Portable and I don't see it being
capable of any digital voice modes. However, in simplex
mode, the unit can transmit a 'data burst' to send a
text message. Not sure if that would be permitted under
GMRS rules either. Chances are (hopefully) you heard
'intermod' on your scanner...

(Looked at their mobile as well, not digital capable as
far as I could see)

 

[dkcorlfla]

Probably your scanner with the better antenna, & coax is being overloaded, so you’re getting intermod. That’s what happened to me when I upgraded the antenna on Yaesu base scanner.

I was thinking it could be intermod or maybe Spurious emissions but the scanner (BCD996P2) has a solid front end and I have not heard it get overloaded on anything else. The signals that I hear are not like regular DMR with long periods of data. Instead I hear short burst at random times with an occasional longer but still short data stream.

 

[dkcorlfla]

Do you have an audio sample you can post? If it were APRS it would sound something like this. If the data emissions happen at a regular interval every few seconds or so like this, you may have stumbled upon a CAP+ rest channel

It's defiantly not regular APRS or the really short burst of the CAP+ sample. I do not have a audio sample available because I'm still working on my station setup. I need to buy a TEE so I can run both the scanner and my SDR on the same antenna. When I get that done I will be able to record using the SDR.

The sound that I hear really does sound like DMR and I just heard a longer data stream on 462.675 (ch 20) it was not strong, only had 2 bars on the scanner but it was clear and steady. Hopefully it's not illegal DMR on the GMRS channel :-(

 

[dickie757]

Also, any digital mode on GMRS is not permitted legally.
Looked at this BTECH Portable and I don't see it being
capable of any digital voice modes. However, in simplex
mode, the unit can transmit a 'data burst' to send a
text message. Not sure if that would be permitted under
GMRS rules either. Chances are (hopefully) you heard
'intermod' on your scanner...

(Looked at their mobile as well, not digital capable as
far as I could see)

Garmin got the rule changed to allow data over GMRS. Their rino brand is APRS for GMRS. It will show, on the map, other rino users nearby. It's a proprietary protocol. If @dkcorlfla can get an audio sample, I'll feed it to my rino (never ever thought I'd say that!!).

 

[dkcorlfla]

Garmin got the rule changed to allow data over GMRS. Their rino brand is APRS for GMRS. It will show, on the map, other rino users nearby. It's a proprietary protocol. If @dkcorlfla can get an audio sample, I'll feed it to my rino (never ever thought I'd say that!!).

You have made me curious about the Rino, I will look it up and try to learn more about the mode they are using for the APRS.

 

[Skypilot007]

I wouldn't say the BCD996P2 has a "solid front end". Take a ride into a large metropolitan are and you'll see how not solid the front end of a BCD996P2 receiver is. Out in the woods where I am it's fine. Also lots of folks using DMR around here on GMRS, so you may just be hearing folks that don't know any better or just don't care. Happy hunting!

 

[kinglou0]

Also lots of folks using DMR around here on GMRS, so you may just be hearing folks that don't know any better or just don't care.

Just don’t care is a big one out here in my neck of the woods. Not bothering with licensing and/or not caring about emission rules.

Frankly, the FCC, Amazon, and the Chinese manufacturers have all contributed to the mess that is GMRS/FRS. I’m not saying it’s entirely a bad thing because it is getting more people curious about amateur radio. Getting more than the retired potbellied whackers into the hobby is how we keep our privileges and possibly my sanity.

 

[mmckenna]

I’m not saying it’s entirely a bad thing because it is getting more people curious about amateur radio.

Unfortunately they often bring the same attitude in with them. "FCC doesn't care". "The rules apply to EVERYONE -but- me". "I'll do whatever I want because 'when all else fails'". Case in point, those hams that assume GMRS is an extension of the 70cm band, or those that assume they have free and unfettered access to public safety systems with their ham license.

The issue is that many don't take the time to comprehend the reason for the FCC rules, and assume they are just there to keep their personal freedoms suppressed. These are the same individuals that make it impossible for us to have nice things.

There is only ONE FCC experimental license that permits a small group to use DMR on a couple of GMRS frequencies in a very limited area for testing/proof of concept.

 

[Craigmoe]

Unfortunately they often bring the same attitude in with them. "FCC doesn't care". "The rules apply to EVERYONE -but- me". "I'll do whatever I want because 'when all else fails'". Case in point, those hams that assume GMRS is an extension of the 70cm band, or those that assume they have free and unfettered access to public safety systems with their ham license.

The issue is that many don't take the time to comprehend the reason for the FCC rules, and assume they are just there to keep their personal freedoms suppressed. These are the same individuals that make it impossible for us to have nice things.

There is only ONE FCC experimental license that permits a small group to use DMR on a couple of GMRS frequencies in a very limited area for testing/proof of concept.

Couldn't agree more...

 

[CaptDan]

There are several Radioddity model radios that are capable of being programed to operate DMR on GMRS Frequencies. They also offer some basic encryption. None of this operation would be legal on GMRS but the no one cares attitude abounds everywhere.

 

[mancow]

Unfortunately they often bring the same attitude in with them. "FCC doesn't care". "The rules apply to EVERYONE -but- me". "I'll do whatever I want because 'when all else fails'". Case in point, those hams that assume GMRS is an extension of the 70cm band, or those that assume they have free and unfettered access to public safety systems with their ham license.

The issue is that many don't take the time to comprehend the reason for the FCC rules, and assume they are just there to keep their personal freedoms suppressed. These are the same individuals that make it impossible for us to have nice things.

There is only ONE FCC experimental license that permits a small group to use DMR on a couple of GMRS frequencies in a very limited area for testing/proof of concept.

Law as defined as opposed to law as applied:

The rules DO apply to everyone but me if I have enough cash.
Testing what, a new product? It's not like we don't know what TDMA will do at 467 MHz or whatever. I wish the FCC would drop the "technical" aspect and lies and just admit it's a financial gatekeeping/grifting operation. If you are big enough, something like (Garmin), they bend the rules and take a long warm piss on the rest of us.

Hell, CC won't even trip on TDMA but locks up 24/7 with kids pushing the bleeep bleeep button over and over incessantly. What a technical and societal propulsion that is.

 

[kinglou0]

If you are big enough, something like (Garmin), they bend the rules and take a long warm piss on the rest of us.

Bingo. I’ve been a licensed amateur for over 25 years, paid my GMRS license fee, and play by the rules but given the current environment of enforcement by the FCC, why even bother?

Alibaba, Amazon, or Ebay gets me virtually any kind of radio on almost any frequency range in whatever emission type I want to use.

Running over the Part 15 power limits on the FM broadcast band? The FCC is coming for you. Causing intentional interference on a GMRS repeater? By all means, keep it up.

 

[dkcorlfla]

Update - think I'm getting this sorted out. Looks like what I'm hearing is intermod on my Retevis RT-95 when I have it monitoring GMRS. I had it on 462.550 at the same time as I had my SDR on the same. I heard a strong DMR signal on the RT-95 but not a trace on the SDR. I also had the Scanner running in scan mode so it might have missed it or did not get the same intermod. Both the RT-95 and the scanner are close together so it's hard to tell what is picking up the intermittent signal when on the other side of the room. After looking at the frequency around the GMRS channels I found a lot of very strong commercial digital using the SDR so what I was hearing most likely was intermod.

 

[mmckenna]

That would make sense. Around me there are a lot of commercial digital systems very close to the GMRS allocations.
Also, the entry level radios like that tend to have hot receivers with less than stellar filtering, so intermod is just a reality of life.

 

[tjpeterson1]

Just picked up a couple Btech GMRS Pro, and can confirm it is very short burst, of half second or so for the data messaging. so just a blip for the data transmit function. these radios do have a nice scanner in them 136-174 and 400-520 MHz, but you have to program specific frequencies in to the channel group to scan. no scanning a range of frequencies.

 

[JASII]

Radios that share GPS location and can perform simplex testing interest me.

Are the various Garmin RINOs, BTECH GMRS-PRO and the Motorola Talkabout T800/801s the only choices for GMRS radios that will share your position and do simplex texting?

Does anybody know how long the text message can be? If I recall correctly, the Garmin RINOs are limited to 13 characters in a so-called "note".

It looks like this is the applicable rule for this.

95.1787 GMRS additional requirements.​

Each hand-held portable unit transmitter type submitted for certification under this subpart is subject to the rules in this section.

(a) Digital data transmissions. GMRS hand-held portable units that have the capability to transmit digital data must be designed to meet the following requirements.
(1) Digital data transmissions may contain location information, or requesting location information from one or more other GMRS or FRS units, or containing a brief text message to another specific GMRS or FRS unit. Digital data transmissions may be initiated by a manual action of the operator or on an automatic or periodic basis, and a GMRS unit receiving an interrogation request may automatically respond with its location.
(2) Digital data transmissions must not exceed one second in duration.
(3) Digital data transmissions must not be sent more frequently than one digital data transmission within a thirty-second period, except that a GMRS unit may automatically respond to more than one interrogation request received within a thirty-second period.
(4) The antenna must be a non-removable integral part of the GMRS unit.
(5) GMRS units must not be capable of transmitting digital data on the 467 MHz main channels.
(b) [Reserved]