BTECH GMRS-V1 to FRS Motorola

[jgnelson]

I just got a BTECH GMRS-V1 and I have an old Motorola FRS K7GMJBGJ.  I set the BTECH to GMRS Channel 1 and the Motorola to Channel 1, key the motorola and can here it on the BTECH, but not vice versa.  Not sure what I am missing, or really if its possible.

 

[wayoverthere]

It should be possible  My first thought is there is a PL tone set on the Motorola, so it's expecting a tone the btech isn't sending. The btech, onthe other hand, is listening with no filter, so it hears the Motorola.

If you can't find the tone settings in the Moto menu, I believe v1 can scan for the code (I'll try to dig up the manual later on the computer, if someone doesn't beat me to it)

[jgnelson]

Yes it does, have to find out what they are.  There is a separate number under the channel on the Moto.  Set it to 0 and bingo heard it.

[wayoverthere]

Google turned up this doc, which may match up with the tones on the Motorola.  You could put the code number on the Motorola, and the corresponding tone on the btech, and see if it gets through still.

https://www.cert-la.com/downloads/radio/FRS-GMRS-Frequency-Chart.pdf

[jgnelson]

Yep figured it out, thank you.  Also figured out that only 1-30 are programmable to RX/TX and then everything else is RX only.

[wayoverthere]

5 minutes ago, jgnelson said:

Yep figured it out, thank you.  Also figured out that only 1-30 are programmable to RX/TX and then everything else is RX only.

Yep, one of the limitations of btech's method of locking down for 95e certification...the gmrs 50x1 has the same limitation.

[PACNWComms]

With many organizations and entities using radios, as the price come down, and availability goes up......analog radio, and features that used to be marketed as options have become the norm. Sub-audible tones, Continuous Tone-Coded Squelch System (CTSCC) and Private Line (PL) as marketed by Motorola is now on almost all radios. Since many hobby users do not wish to spend large amounts of money on Radio Service Monitors, they are thousands to tens of thousands of dollars (Hewlett Packard 8920, and newer Aeroflex 3920 for example), I have often recommended the Surecom SF401 Plus tester. 

This small tester shows frequency and tones in use, if used, on analog radios. This, along with the Surecom SW102 wattmeter have become common items I have used when not working in public safety radio, or when I do not want to carry a large and heavy test set to check a radio that may not be as tight of spec as digital radios. I also tend to use Surecom gear when dealing with older analog only radios, as shown in the picture, working with Motorola EX600XLS handhelds that were shipped from a remote site, to my remote site at that time. I had no room for larger and heavier, and more expensive test equipment. I was given no information besides the radios, and what was shown on their display. There was no printout of the codeplug, no programming computer at the site, and no cable to read the radio. So, the Surecom tester worked well in this case. They are decent for hobby use, and cheap enough to afford if you do not working radio professionally.

[MichaelLAX]

Can I feed an audio signal from my radio into the FT-401+ to decipher the Tone, or does it only work on RF nearby it’s antenna?

[Sshannon]

7 hours ago, MichaelLAX said:

Can I feed an audio signal from my radio into the FT-401+ to decipher the Tone, or does it only work on RF nearby it’s antenna?

I’ve read that the audio coming out of a radio that’s designed for tones has already had the low frequency tones filtered out so that probably wouldn’t work.

Here’s the article on Wikipedia: https://en.m.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System

It says: “In a communications receiver designed for CTCSS, a high-pass audio filter is supposed to block CTCSS tones (below 300 Hz) so they are not heard in the speaker. Since audio curves vary from one receiver to another, some radios may pass an audible level of the CTCSS tone to the speaker.”

[PACNWComms]

7 hours ago, MichaelLAX said:

Can I feed an audio signal from my radio into the FT-401+ to decipher the Tone, or does it only work on RF nearby it’s antenna?

Only use it with its antenna. In the instructions, which are typical Chinese to English translation, they tell when to move the radio under test closer or further away to optimize the possibility of getting the correct frequency and tone (this is not a precision tool at about $50 in cost). Connecting the radio under test directly to the Surecom FT401 Plus will be like having the radio too close, and you may have to use the attenuator, and still get readings that are incorrect. There is the capability to use it with DMR radios as well, but that is not too accurate either. This is a cheap tool for getting close, when you do not have the ability to lug around an Aeroflex 3920. But, it is useful for finding the approximate frequency and tones, and doing several tests a few seconds apart gives you something useful. 

I have co-workers that often receive radios that they may not have programming cables or software for, and need to know if they are VHF/UHF/800 Mhz....and tones in use quickly, these work well for that. I tell them that a company issued smart phone and the model number, along with Google, work much better. I work for a large corporation where the radio shop is staffed with former electricians, and a few that have actually worked in radio....training could go a long way. Even joining these forums would probably help, but may confuse. For a $50 tool, it does help though, and for hobby use, makes a decent frequency/tone counter. If it was $100, I would say to get a Radio Shack scanner with near field mode instead.

[PACNWComms]

10 hours ago, MichaelLAX said:

Can I feed an audio signal from my radio into the FT-401+ to decipher the Tone, or does it only work on RF nearby it’s antenna?

Attaching a highlighted version of the "manual" ....well the one English page anyway, highlighting the portions with limitations and why it does not work with a cable directly between the radio and tester. I wish it did work this way, but it would need a better attenuator, and I am sure somebody would connect a 50 watt mobile to it at some point. There is always somebody that will do that type of thing to a piece of measurement or test equipment, at every price point. (flashbacks to my early career when engineers would put 50 watts to a 5 watt max connector on Anritsu/Hewlett Packard - Agilent/Marconi/Motorola service monitors). 

SF401PLUS-manualHighlighted.pdf

[Sshannon]

A person could probably make something using one of the wideband SDR receivers, which are not filtered to remove sub tones. A software filter to remove everything above 300 Hz would allow you to see just the sub tone, which could even be fed into a multimeter with a frequency setting. 
Of course a cheap uv5r has the ability to scan for privacy tones so maybe that’s the easiest. 

[PACNWComms]

17 hours ago, Sshannon said:

Of course a cheap uv5r has the ability to scan for privacy tones so maybe that’s the easiest. 

And cheaper too, depending on accessories and all. I have a UV-5R and a GT-3 somewhere, but would have to dig/find them.....then probably get new batteries for them. At work, we have a "no Chinese radio" rule, as some sites were busted for using FRS/GMRS (pre-2017). The corporation uses Motorola, Kenwood and Icom radios, Motorola for public safety, Icom for aviation, and Kenwood for confined space radio use. So, the Surecom SF-401 Plus was only allowed as it was not a "radio" (transmitter), and there is a serious knowledge and learning curve with many of the radio technicians. Some never used a Radio Communications Service monitor before this job. Great point on the using a Baofeng for finding CTCSS tones, could be useful for many on this site.

[Sshannon]

48 minutes ago, PACNWComms said:

And cheaper too, depending on accessories and all. I have a UV-5R and a GT-3 somewhere, but would have to dig/find them.....then probably get new batteries for them. At work, we have a "no Chinese radio" rule, as some sites were busted for using FRS/GMRS (pre-2017). The corporation uses Motorola, Kenwood and Icom radios, Motorola for public safety, Icom for aviation, and Kenwood for confined space radio use. So, the Surecom SF-401 Plus was only allowed as it was not a "radio" (transmitter), and there is a serious knowledge and learning curve with many of the radio technicians. Some never used a Radio Communications Service monitor before this job. Great point on the using a Baofeng for finding CTCSS tones, could be useful for many on this site.

I’ve tested it and it seems like it works.  A friend got a Wouxun KG-805G and it doesn’t appear to have the ability to scan for CTCSS.

Someday I’d love to try one of those Motorola radios some of you have, but for now I’m pretty happy with my Garmin Rino. 

[PACNWComms]

27 minutes ago, Sshannon said:

Someday I’d love to try one of those Motorola radios some of you have, but for now I’m pretty happy with my Garmin Rino. 

I still use a handful of Garmin Rino (530's and one 120, pre-micro SD card versions) when me and my family go out into the wilderness. Having the ability to "see" location on a map is beneficial....they are good little units. Although, I will not spend $500-700 on a newer Garmin Rino. I think they have gone a bit too far on features for the price on the newer series. I used the Garmin to augment the Motorola XPR7550e when in Billings, during an oil spill a few years back. UHF got out a bit on that side of the state, and almost as far when in Stevensville in the west.

[RobertHode]

I just got an email for this: https://baofengtech.com/new-release-btech-frs-b1/?mc_cid=69572b7713&mc_eid=a14df999bc