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Retevis RA25- 20W GMRS mobile


Shadow471
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Retevis is well known for manufacturing and selling some of the most inexpensive radios around. I have no experience them. I have seen some of there products talked about periodically on some YouTube channels.

 

If considering a product of theirs, perhaps consider an equivalent product from Midland, at least if you purchase it from them there is some chance you will be able to obtain product support should it ever be needed.

 

Michael

WRHS965

KE8PLM

 

 

Sent from my iPad using Tapatalk

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Two comments:

  1. There is a V/M button which means there is a VFO. Programming from the keypad makes it ineligible for Part 95e centification.
  2. I'm constantly amused when the Chinese call these mobile units "walkie-talkies" in their eBay listings and/or digital ads.
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Two comments:

  1. There is a V/M button which means there is a VFO. Programming from the keypad makes it ineligible for Part 95e centification.
  2. I'm constantly amused when the Chinese call these mobile units "walkie-talkies" in their eBay listings and/or digital ads.

 

to be fair, the Btech GMRS 50x1 (also supposedly 95e certified) has a V/M button as well, and it will happily let you scan through and receive a big chunk of the VHF and UHF bands. 

 

However, it doesn't let you transmit on anything other than the hard coded 1-7 and 15-22 (simplex on 1-7, simplex or duplex on 15-22)...the Retevis may be similarly locked down

 

the frustrating part about implementing the lockdown this way is that even if the extra stuff you've programmed is in bounds for GMRS, nope, rx only.

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Two comments:

  • There is a V/M button which means there is a VFO. Programming from the keypad makes it ineligible for Part 95e centification.
  • I'm constantly amused when the Chinese call these mobile units "walkie-talkies" in their eBay listings and/or digital ads.
Your comment caused me to go back and re-read the rules to see if I could reach your conclusion. Instead I ended up again concluding that a part 95e radio cannot, under any circumstances, feature the ability to transmit on any frequency that is not a GMRS frequency and that said responsibility for this lies with the internals of the radio transmitter. In simple terms, nothing that the user can do from the exterior of the radio (via its control panel or via external software) shall enable to radio to transmit on any frequency that is not a GMRS frequency. I did not conclude that a VFO could not exist, but I do conclude the absence of a VFO in combination with the complete absence of external programming capability is a means to achieve compliance.

 

Now, the reason that I do not conclude that the presence of a VFO button alone makes the radio ineligible for part 95e compliance is basically this. In order for a multi-channel GMRS radio to be useful there needs to be a means to switch between authorized frequencies. Channels are one means of doing this. A channel is however, at its essence, a radio preset that maps one or more big numbers (frequencies and settings) to a short, more-easy-to-remember, number. This equates to a radio memory. A VFO at its essence can do the same thing, but instead it enables the user to choose the frequency and other settings through direct entry.

 

The VFO violates FCC intent if (in my opinion), by means of using the VFO, the radio suddenly has the ability to transmit on frequencies that are not allowed. But, this is where the radio internals come in. While the user may be able to tune to and receive signals from many different frequencies, it is the internals of the radio that are responsible ensuring transmissions occur only on authorized frequencies (frequencies for which it is certified).

 

By case and point. I own a particular amateur HT. The radio is only permitted to transmit on amateur frequencies, yet is is capable of receive on 10s of thousands of frequencies. The radio features both VFO and channel selectors. However, any attempt to Tx on a frequency outside the amateur radio allocations, whether by VFO or by channel selector, is blocked and both a tone and message are presented to the user.

 

My conclusion therefore is that VFO can exist on a part 95e radio, but the radio shall not have the ability to transmit on any frequency that is not a GMRS frequency.

 

For those that wish to read more, refer to Part 95.1761. And here is an excerpt from paragraph 2 with is speaks to “GMRS transmitters”:

“...All frequency determining circuitry (including crystals) and programming controls in each GMRS transmitter must be internal to the transmitter and must not be accessible from the exterior of the transmitter operating panel or from the exterior of the transmitter enclosure...”

 

Michael

WRHS965

KE8PLM

 

Edited to resolve text errors.

 

Sent from my iPad using Tapatalk

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Wonder if the FCC is even legal on that, especially after the whole Rugged Radio FCC letter... most of those radios were supposed to be "Scanners" under FCC... with a PTT?

 

G.

Many amateur transceivers receive only a part 15 certification for their receivers. Evidently, rugged thought they could get away with that, too. Doesn't work that way for part 90 radios.

 

Sent from my SM-A102U using Tapatalk

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  • 3 weeks later...

I bought one of these for the Christmas Special price. It has a FCC ID sticker on it  2ASNSRA25. So far, that does not return as valid in the FCC database. I have not been able to access all of the menu options required to change the PL Tones, and a few other items. I have tried reading the Chinglish manual from every angle, but sill no luck. I contacted Retevis, and they sent me the programming software. Unfortunately, no programming cable came with the radio, and none were offered as options. I am waiting for their reply about ordering a compatible cable. The radio appears to have an adequate heat sink.  The VFO allows XMIT from 400-481.615, and RX only on VHF frequencies. I will ask Retevis about the apparently bogus FCC ID that they are claiming for this radio. If they can get a legitimate 95E grant, and make the UI work AND work in a user-friendly manner, they will have what looks like a good competitor for Midland. I do not have a service monitor so I do not know how sloppy this radio is. If I can get it programmed, I will test the XMIT power.  

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  • 3 weeks later...
  • 1 month later...

I have also ordered one of the RA25 units along with the programming cable. Retevis said it would take 4-5 weeks to get to me under regular shipping.

 

I have been playing around with the software and here is what I have noticed:

After extracting the files, you get 2 default files along with the program itself.

One default file is for the VHF/UHF version of the radio the other is for the GMRS version

A9198A-RA25-Codeplug-210116.dat

A9198B-GMRS-Codeplug-210116.dat

Loading the VHF/UHF version, you can enter the frequencies you want.

Loading the GRMS version, the GRMS frequencies are already entered and you cannot change them. You can add a channel name, the CTCSS/DCS codes and most other options, but not the frequencies.

Also the FRS only channels (8 - 14) are not listed.

ScreenShot 1 shows the VHF/UHF version. Double clicking the” MORE >>” on a CH number will bring up the Channel Edit window.

When you type in a frequency, you will be able to edit all the info in this window.

ScreenShot 2 show the GMRS version.

ScreenShot 3 has the Channel Edit window. Notice that the Frequencies are already there and are grayed out.

As far as VFO, in the GMRS version you can't add frequencies.

The CTCSS/DCS codes in the GMRS version are the same in any other Retevis GMRS radio.

I have been using RT76 portables from Retevis and did change the codes for my situation, but if you are using the radios in Simplex mode, it's “out of the box” communications.

Once I get the RA25, I will do an update to the forum.

 

post-125-0-73081800-1614525691_thumb.jpg,post-125-0-15763700-1614525699_thumb.jpg,post-125-0-28115900-1614525713_thumb.jpg

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Here is the FCC GMRS spec for Bandwidth:

§95.1773   GMRS authorized bandwidths.

Each GMRS transmitter type must be designed such that the occupied bandwidth does not exceed the authorized bandwidth for the channels used. Operation of GMRS stations must also be in compliance with these requirements.

(a) Main channels. The authorized bandwidth is 20 kHz for GMRS transmitters operating on any of the 462 MHz main channels (see §95.1763(a)) or any of the 467 MHz main channels (see §95.1763©).

(B) Interstitial channels. The authorized bandwidth is 20 kHz for GMRS transmitters operating on any of the 462 MHz interstitial channels (see §95.1763(B)) and is 12.5 kHz for GMRS transmitters operating on any of the 467 MHz interstitial channels (see §95.1763(d)).

 

GMRS radios are Part 95 and as such have a 20 kHz separation.  Channels 8 - 14 are the half watt 467 MHz interstitial channels which are not available on the RA25.  Even though 12.5 kHz is displayed on the GMRS Codeplug, clicking on it does nothing.

 

Of course, since I don't have the radio yet to use, I can only speculate how the software and settings work. 

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It would be of interest to look at the sample code plugs using a Hex Editor. It might be possible to edit the GMRS code plug for features or frequencies the radio programming software disables. It could be as simple as saving a code plug for the VHF/UHF version. Find where a configuration value is set that identifies which radio the code plug it is for using a Hex Editor, change it, then reload it using the radio software to down load it.

 

I’ve looked at the code plug for one of my Kenwood commercial radios, TK-3170. However beyond the header the contents are encrypted, apparently, by using a simple XOR logical operation between the data and a key value. I was able to recover the embedded two line by 32 character message block this way along with channel names and other text. I haven’t done much more than this at the moment.

 

For a commercial grade radio I can sort of see why it would be encrypted but for a consumer grade radio I think it’s unlikely.

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  • 5 months later...

I have this model with firmware V2.01. I can't access menu items 1-16, unless I set the unit to UHF (400-470Mhz) mode. However, all the GMRS channels are gone. Does anyone have a code plug for the GMRS channels and UHF mode? When in GMRS mode, I can't change necessary settings.

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Yes, code plugs are available.

Radioddity's v2.02 CPS software already includes those channels; see screenshot below (and yes, Radioddity seems to have the Channel Spacing and TX Power settings set incorrectly for some of those channels):

These are tips for the "similar" Anytone AT-799UV a/k/a Radioddity DB-20G:

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

Open up the Ham 2 meter and 70 cm bands to transmit on the USA version:

1) Turn off the power.  

2) While holding down the V/M button, turn on the power.  Use the Up and Down arrow keys to change from the GMRS setting on the display to 136-174 MHz; 400-470 MHz and now power down.  

3) When you power back up licensed operators can now transmit on the GMRS channels and the 2 meter and 70 cm Ham bands. 
----------------------------------------------------------------

Giving a Channel an alphanumeric name without using a computer:

1) Go to the appropriate Channel

2) Push the FUN button and using the V/M and MAIN buttons to go through the Menu items until you reach Function 29: DSPCHANNEL and using the Up and Down arrow buttons, select NAME. Push the FUN button to exit the Function menu.

3) Push the FUN button and using the V/M and MAIN buttons to go through the Menu items until you reach Function 12: CHANNEL NAME.  Using the Up and Down Arrow buttons, scroll through the list of 1-0, A-Z and a-z to find the first letter.  When you do find it, push the MON button to confirm that character and move to the 2nd position.  Repeat as necessary until up to 8 characters are entered.

4) When finished push the FUN button to exit the Function Mode.
----------------------------------------------------------------

Programming a repeater channel without using a computer:

1) Switch to VFO mode (from Channel Mode) using the V/M key

2) Using the number keys on the mic, enter the repeater's output frequency

3) On the mic, push FUN then 9 repeatedly until the proper split (+ or - or blank for Off) appears above the frequency.

4) Press the FUN key on the Radio and use the V/M and Main keys as an up/down to get to function 10:Offset.  

Use the Up and Down arrow keys to set your offset split, such as 5.00000MHz or 0.60000MHz (you can hold down the Up or Down key to have it continuously change). 

Once you get to the proper offset, push the FUN key again.

5) Press the FUN key on the Radio and go to Function 01:T-CDC and use the Up and Down keys to find the proper transmit PL Tone.  

Use the same method to optionally set the proper receive PL Tone, if necessary, on Function 02:R-CDC (or Function 03: RT-CDC if both tones are the same)

6) You can rotate through High, Medium and Low transmit power using FUN and 0 (zero) on the mic.

7) Save to the first open channel by pushing Fun and UP on the microphone (or then use the UP and DN keys on the mic to scroll through the available channels, with empty ones saying NULL

😎 Save to this channel holding down the "MON-*" key on the mic and you are done!
----------------------------------------------------------------

Use DCS Digital Tones:

Go to desired channel
Press FUN on mic
Press 1 on mic
Go to menu 1 using V/M or Main key on mic
Press number 1 on mic to cycle to 000 N display for menu 1
Use up and down on mic to scroll to code corresponding to desired DCS code. 
List is in the instructions.
Use V/M or Main to go to menu item 2. Repeat selection process
Press DIL on mic to exit.
_________________________________________________________________

New Radioddity DB20-G CPS software V2.02
1. Change the default bandwidth from Narrow to Wide.
2. Address the bug that "when repeater TX frequency change, RX frequency automatically match"
----------------------------------------------------------------

Screen Shot 2021-08-30 at 10.38.39 AM.png

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34 minutes ago, pcradio said:

Thanks guys, I got it. I was just hoping someone had a RA25 code plug. I manually entered them all in the software. A pain, but now done.

I told you I had code plugs but it is a good educational exercise to do them yourself. 

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For fun, I wanted to see the power draw on the Retevis RA25 mobile radio. I connected it to an AC to DC Converter 12V 5A 60W Power Adapter (Alitov brand.) . Then the adapter was plugged into a Kill-A-Watt meter.

 

Idle
~ 2W
~ .06A

Receiving on channel 16 (462.575) high power
~ 10W
~ .10A

Receiving on channel 16 (462.575) medium power
~ 4W
~ .06A

Receiving on channel 16 (462.575) low power
~ 3W
~ .06A

Transmitting on channel 16 (462.5750) high power
~ 48W
~ .71A

Transmitting on channel 16 (462.5750) medium power
~ 32W
~ .51A

Transmitting on channel 10 (467.6125) low power
~ 20W
~ .33A

 

 

 

 

819yx-Xkt-Sy-L-AC-SL1500.jpg

 

 

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