Looking at Motorola/Vertex hand helds...

[BoxCar]

The Vertex brand is originally Japanese and was a well respected brand that was purchased by Motorola around 2007. The Vertex brand of mobile radios was gone by 2010 after going through the double branding of Motorloa/Vertex, A lot of Part 90 agencie used the Vertex on the lower VHF band for their reliability. I don't know about the newer stuff that's coming out with the Vertex brand.

[wayoverthere]

7 hours ago, BoxCar said:

The Vertex brand is originally Japanese and was a well respected brand that was purchased by Motorola around 2007. The Vertex brand of mobile radios was gone by 2010 after going through the double branding of Motorloa/Vertex, A lot of Part 90 agencie used the Vertex on the lower VHF band for their reliability. I don't know about the newer stuff that's coming out with the Vertex brand.

I suspect mine are from that overlap period...the evx's all say designed in Japan, assembled in china, while the vx's (925 and p824) say made in Japan. The mobile, I can't get at the label but I think some of the paperwork with it referenced yaesu.

On a side note, I realized today that the g7 evx's actually came with Motorola batteries, rather than vertex...little more capacity than the vertex one with the 3rd (2200maH vs 1800, if I remember right). Given they came with 2 chargers and a vertex speaker mic, not a bad deal.

[Lscott]

Did anybody consider trying the Kenwood TK-3360, or the older model TK-3160 radios? They have about the same feature set as the basic VX-261 units.

https://www.motorolasolutions.com/content/dam/msi/docs/EA_Collaterals/ENGLISH/commercial/portables/vx260_series_spec_sheet_ea.pdf

The Kenwood radios will do wide and narrow band FM, use various battery pack types including Lithium Ion, plus all you need is a cheap Baofeng type cable to program them. In fact many of the cheap Chinese radio accessories, like speaker mics, work on the Kenwood radios. The software I found on line to down load fairly easy. The VHF models work nice as MURS radios, make sure the power is set to low, with enough channels left over for NOAA weather monitoring.

https://www.kenwood.com/usa/Support/pdf/TK-2360_3360.pdf

http://astralcommunications.com/site/wp-content/uploads/2013/01/TK-2160_3160.pdf

I see the UHF version radios selling on eBay frequently in various states of condition, some are the full package, radio charger, battery pack and antenna. As I've mention before Kenwood radios will program outside of the stated band split. So if necessary even a few Ham 70cm frequencies can be used.

[jlag]

On 11/26/2019 at 3:34 PM, Radioguy7268 said:

The only potential GMRS trouble I've seen with the Motorola branded EVX-S24 and EVX-261 is getting them to work in Wideband. The Motorola units I've gotten in are strapped as Narrowband out of the Box, and I've yet to be successful in changing them over to Wideband. I've done that with ease on Vertex labeled units, but there's something that I haven't bothered to figure out when it comes to the MSI branded version.

 

I've heard people say that you NEED to use the FIF-12 cable in order to use the Wideband enablement mode (as well as using the Export version of software) - but I haven't bothered to try that out, as my basic Vertex cable worked for updating (backdating?) previous Vertex units to Wideband enablement.

 

They do seem to be great little units for the price.  Be aware that the EVX-S24 is only listed at 2 watts for Analog UHF (3 watts DMR).

 

*Edit - just noticed that you specifically said the VX-261.  Same issues may apply, but the analog VX-261 is a screaming steal in the Used market. I've been snatching them up in good condition at less than $40 per unit with accessories.

I have a Vertex branded EVX-539 that the recovery tool 1.03 is stating "Product Type Error" using the FIF-12. This same tool worked on Moto branded S24's and lists "EVX-530 Series" in the dropdown selection but no dice when it runs. Would you have any clues?

[jlag]

On 5/12/2021 at 9:05 AM, Lscott said:

I don't know about Vertex or Motorola radios how the frequency range is verified, but with Kenwood I do. Maybe Vertex or Motorola radios are similar.

The radio programming software reads the code plug which has the radio's model number and sub type embedded in it. When the software tries to write the code plug to the radio it first queries the radio for model and sub-type. If the two don't match the software generates an error message. One version of the software with the license key I used for installation even offered to let me change the "market code" changing a radio from a European or Asian model to a US type! The service manual claimed if you used the wrong model type, and the associated market code, to program the radio "the first time" it can't be changed later. Apparently that's not true if you have the right software.

Some of the Kenwood radios use "XOR" encryption on the code plug contents I discovered, for example the popular TK-3170 and TK-3173 radios. After some lucky guesses and looking I found where in the code plug the encryption key is stored. It seems to be located in the same place even between totally different radio models. I suspect the software programmers used the same code plug file structure for the beginning section across model types. The key however can vary from code plug to code plug even for the same model type.

After decrypting the code plug the version of the radio software, radio model type and the installation license key, used to install the software which created the code plug, was found. The frequency was stored in little Endian integer BCD  format. For example 462.67500 MHz was stored as 00 75 26 46, two BCD digits packed into each byte.

Any passwords set in the radio, such as power up enable, radio read or radio over write are also stored in the code plug. Without the engineer's license key for example even if you loaded the code plug in to the programming software the radio over write password is blanked out with asterisks. If you know where to look in the decrypted code plug even that password is in the clear and can be recovered allowing a radio to be reprogrammed. The software will prompt the user for the password if one is used and will refuse to either read the radio or over write the current code plug depending on which passwords are set.

The channel names, group names, strings in general, are stored in normal ASCII format.

Other options and features are likely stored as bit fields or some other type packed data structure. Since none of this will ever be documented by the manufacture so a good deal of experimenting has to be done to reverse engineer the code plug further.

@wayoverthere @Lscott Looks like I am a fool. The Vertex CPS yells at you when you try to program OOB but it lets you do it. I swear my eyes were playing tricks on me and the frequency was reverting to the low end when I did it a month ago. Played with it again tonight and I now have a Moto branded EVX-S24 (403-480) RXing public safety in the 480's and a Vertex branded EVX-534 (450-512) TX-RXing in the 440's (can do 4 & 5 KHz deviation as well) just using the CPS. The RX in the 480's sounds good, I don't notice any sensitivity loss. I will put the 534 on the SA and Watt meter tomorrow and see what it looks like TXing in the 440's into a dummy.

Thanks for all the input.

EDIT PS: Next step is to get the 7.2 volt Mitsubishi MOSFET running on the S24

[Lscott]

1 hour ago, jlag said:

@wayoverthere @Lscott Looks like I am a fool. The Vertex CPS yells at you when you try to program OOB but it lets you do it. I swear my eyes were playing tricks on me and the frequency was reverting to the low end when I did it a month ago. Played with it again tonight and I now have a Moto branded EVX-S24 (403-480) RXing public safety in the 480's and a Vertex branded EVX-534 (450-512) TX-RXing in the 440's (can do 4 & 5 KHz deviation as well) just using the CPS. The RX in the 480's sounds good, I don't notice any sensitivity loss. I will put the 534 on the SA and Watt meter tomorrow and see what it looks like TXing in the 440's into a dummy.

Thanks for all the input.

EDIT PS: Next step is to get the 7.2 volt Mitsubishi MOSFET running on the S24

Glad you had success getting the out of band frequencies to work on your Motorola radios. The Kenwood software works about the same. If you enter a frequency outside the of the official range you get a warning message that pops up. If you click to dismiss it the software will accept the entry. It gets tedious when you have a lot of them to enter, but at least it works.

I suggested to a fellow Ham to build a test code plug for a radio he wanted to push petty far out of the official range. Put in frequencies, starting at the boundary of the official range edge, about every 1 MHz apart in successive memories. Then try each one out to see where the radio’s PLL fails to lock, you get a warning tone out of the radio in that case. No guarantee the same range works on another radio of the same model due to component tolerances. 
 

Once you know the limits the next question is power output and sensitivity as you mentioned. That depends on the power amplifier’s output filter band pass characteristics, and the RX section’s filter. 
 

On some radios the power amp filters can be “tweaked” a bit provided the components used have adjustments.

The RX section maybe. Many of the Kenwood radios I’ve looked at use some type of electronically tuned band pass filters. Those I doubt are easy, if at all, possible to tweak. The tuning voltage is likely non linear with the precise value generated by the radio’s micro using an internal formula or look up table.

[wayoverthere]

1 hour ago, jlag said:

@wayoverthere @Lscott Looks like I am a fool. The Vertex CPS yells at you when you try to program OOB but it lets you do it. I swear my eyes were playing tricks on me and the frequency was reverting to the low end when I did it a month ago. Played with it again tonight and I now have a Moto branded EVX-S24 (403-480) RXing public safety in the 480's and a Vertex branded EVX-534 (450-512) TX-RXing in the 440's (can do 4 & 5 KHz deviation as well) just using the CPS. The RX in the 480's sounds good, I don't notice any sensitivity loss. I will put the 534 on the SA and Watt meter tomorrow and see what it looks like TXing in the 440's into a dummy.

Thanks for all the input.

EDIT PS: Next step is to get the 7.2 volt Mitsubishi MOSFET running on the S24

I'll have to give it another try...the g7's were my first forays into the world of commercial CPS, so lots of learning curve. I have some inconsistencies between the two that I want to iron out anyway, and maybe try to get the g6 more consistent in buttons and lighting. I have the startup messages programmed with call signs and range label (g6/g7). Also done a vx924, and now a p824, and each version has its quirks...I've fiddled with the button/switch settings a bit on the 924 a few times, if I'm honest.

[WRFP399]

So I know I am reviving an old threat but I found what appears to be a work around for the Wide Band Recovery Tool and at least my EVX-534.

I purchased a used EVX-534 on eBay for $40.  When it came it was locked to narrow band. I am using the export version of CE151 which would allow wideband if the radio wasn't locked to it. I tried using the Wide Band Recovery Tool but I have simple USB programming cables and not the Vertex FIF-12. The Recovery Tool did not like the cables I had.

On the off chance I tried to upload the stock EVX-534 programming files that come with CE151. I am now being allowed to program wideband as needed. No FIF or Recovery Tool Needed. I attached a screen shot showing the two test channels I put in.