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GMRS HT Round Up


WRPCinci

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If it qualifies as GMRS, the 462MHz interstitials are allowed up to 5W ERP wide FM -- only the 467MHz (which were only granted to GMRS with the 2017 reorganization) are 0.5W ERP NFM (and the regulations state that "Each GMRS transmitter type capable of transmitting on these channels must be designed such that the ERP does not exceed 0.5 Watt.", which could be interpreted to mean no capability for a gain antenna to be installed. This proviso does not appear on the 462MHz interstitials).

If it is deemed an FRS radio, all channels are limited to NFM, 467MHz 0.5W ERP, 461MHz limited to 2W ERP (I'm probably repeating myself).

 

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On 8/12/2022 at 9:14 AM, back4more70 said:

You can try http://www.pofung.cn/UploadFiles/20211020203444963.zip but I am not positive that is the correct one.  You can also privately send me your email and I can connect you to my Google Drive folder if you like.  The rar file I originally downloaded was named "Pofung T11 programming tool and guid" but of course I cannot find the web site now.

Note: I used my UV-5R programming cable with this software and it worked correctly.

SUCCESS!!!

This software creates code plugs that are unencoded XML.

I used my HEX editor to change the TRANSMIT frequency on Channel 19 to the INPUT frequency for Repeater Channel 19R and used the BF-T11 software to enter the ENCODE CTCSS tone and now I have confirmed at home that these handy little units can transmit and receive on the 5 MHz split!

Now 2 watts is not enough for me to actually access my local repeater from inside my home, but later today when I go driving closer to this repeater, I will confirm that this will actually allow me access to this 650 Repeater:

 

Hex.jpg

BF-T11.jpg

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On 9/10/2022 at 5:16 PM, MichaelLAX said:

SUCCESS!!!

This software creates code plugs that are unencoded XML.

I used my HEX editor to change the TRANSMIT frequency on Channel 19 to the INPUT frequency for Repeater Channel 19R and used the BF-T11 software to enter the ENCODE CTCSS tone and now I have confirmed at home that these handy little units can transmit and receive on the 5 MHz split!

Now 2 watts is not enough for me to actually access my local repeater from inside my home, but later today when I go driving closer to this repeater, I will confirm that this will actually allow me access to this 650 Repeater:

 

Hex.jpg

BF-T11.jpg

Code plug hacking can be a lot of fun, getting a radio to do things the manufacturer doesn’t allow. I did about the same thing with would otherwise be 3 useless UHF 2 channel Kenwood ProTalk radios I got from a buddy for free. Programmed one channel for the typical GMRS road frequency and the other the local GMRS repeater. None of those are in the selection list of preconfigured frequencies for those radios.

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48 minutes ago, MichaelLAX said:

It is like getting a UV-5R with only 2 watts and for half price!

Yesterday, I did confirm that it works on the local 650 repeater, with obvious limitations due to 2 watts.

I could see a pretty cool use case in which a Retevis RT97 repeater is used for a campsite (or a church), and a bunch of little BF-T11 satellites for the users :)

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  • 1 month later...
On 9/10/2022 at 5:16 PM, MichaelLAX said:

SUCCESS!!!

This software creates code plugs that are unencoded XML.

I used my HEX editor to change the TRANSMIT frequency on Channel 19 to the INPUT frequency for Repeater Channel 19R and used the BF-T11 software to enter the ENCODE CTCSS tone and now I have confirmed at home that these handy little units can transmit and receive on the 5 MHz split!

Now 2 watts is not enough for me to actually access my local repeater from inside my home, but later today when I go driving closer to this repeater, I will confirm that this will actually allow me access to this 650 Repeater:

 

Hex.jpg

BF-T11.jpg

Which HEX editor did you use for that?

I was trying to find a way to change the TX frequency for the split, but did not think of doing it that way.

Now I'm wondering if the TX power can be changed as well through the editor.

 

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2 hours ago, NC654 said:

Which HEX editor did you use for that?

I was trying to find a way to change the TX frequency for the split, but did not think of doing it that way.

Now I'm wondering if the TX power can be changed as well through the editor.

 

I did about the same thing with 3 nearly useless Kenwood TK-3200 2-channel ProTalk radios a buddy gave me for free. He had no use for them.

These radios "officially" have 56 per-configured frequencies you can choose from in the programming software or in the radio's firmware when field programing the radio. Non of the frequencies are for GMRS. Further there didn't appear to be anyway to set the TX frequency different from the RX frequency in the software either, so repeater operation was impossible.

Using a hex editor, and some lucky guesses, I figured out where and how the RX and TX frequencies were stored in the code plug. Now I have them programmed for the local wide area GMRS repeater and a simplex channel. Now they are usable for something practical.

TK-2200_3200 Brochure.pdf

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3 hours ago, NC654 said:

Which HEX editor did you use for that?

I was trying to find a way to change the TX frequency for the split, but did not think of doing it that way.

Now I'm wondering if the TX power can be changed as well through the editor.

 

I used Hex Fiend on my Mac.  

I did not attempt to make any other changes to the Code Plug from there, putting the Hex Fiend modified CP back into the BF-T11 programming software to add the Repeater's CTCSS Tone.

Do you think you can get more than 2 watts out of these handi-talkies?

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For HTs I'm using the Wouxn ("ocean") KG-935G. It has good audio, programming software that works and it's also easy to configure from the faceplate of the radio.  The audio is reasonably loud and clear.  Battery is removable and rechargeable and charging cradles are available if preferred. I selected this model because the CTCSS and DCS are programmable from the faceplate easily and it would make it easier to use if the memories were restricted like on the Radioddity DB-20G mobile radio (8 repeater channels for transmit / receive only).  Overall a great HT for the price. Cons would be it's a little bulkier than other HT options (slightly larger external dimensions).

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11 minutes ago, wrtq652 said:

... and it would make it easier to use if the memories were restricted like on the Radioddity DB-20G mobile radio (8 repeater channels for transmit / receive only).  

On your Radioddity DB20-G, try this:

Turn off power

Hold down the V/M key

Turn on power

Note the version of Firmware at the bottom of the screen; which version is it?

The stock DB-20-G with updated firmware allows for DIY repeater channels:

Screen Shot 2022-11-10 at 2.01.49 PM.png

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@MichaelLAX Exactly, on the DB-20G we get a handful of repeater channels and they are customizable (CTCSS/DCS for RX and TX, maybe a few other features, I'd have to check the manual again). A user must decide between deleting a channel or changing the CTCSS/DCS code if the repeaters in the user's area exceed the number of customizable channels.  In our case, repeaters have overlapping frequencies, but some have different tones.  On the DB-20G mobile and on the Wouxn KG-935G HT changing a CTCSS tone is easier than reprogrammnig a frequency from the faceplate.  Thank you for the comment on the DB-20G mobile, it is accurate in that it supports a few programmable channels which can be used for both TX and RX.  The other channels in the radio are also "customizable", however, they are receive only channels, which returns us to the "customizable channels" for transmit channels as described above. 


All:
One other item about the Wouxn KG-935G HT style radio which may be of value is it supports a removable reverse-SMA connection for the antenna. Using an adapter, this can be connected to standard PL-259 "UHF" connector for use with an external antenna, for example on a vehicle.  If you're looking for a way to reduce costs and have definately decided on an HT, having the removable antenna increases the flexibility of the Wouxon KG-935G for use as a mobile radio.  It still only puts out 5 watts max power, however, I'm sure most of us would agree 5 watts on an antenna external to the automobile, is far better than 5 watts inside the automobile on a much smaller antenna.

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51 minutes ago, MichaelLAX said:

Do you think you can get more than 2 watts out of these handi-talkies?

I remember reading a post somewhere on another site that they measured about 4.82 watts output on high power. That was done on 2 radios that were taken apart to the point they could capture the TX power at the base of where the antenna would be. There were a couple other tests done such as frequency deviation, RX sensitivity, and battery life, and all were very good but I do not remember those specifics since I was mostly impressed by the almost 5 watt output. I tried for the last hour or so to find the site, but no luck yet.

Since they are capable of almost 5 watts, then the low power setting might be able to be removed on the FRS portion. I may even try to use these on the 70cm ham bands since I am licensed there as well. All I need to do is find a suitable editor, but the ones I have looked at so far do not have the same layout as the one you used so I will try Hex Fiend and see how far I can get with it.

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@wrtq652 The DB20-G can be easily "opened" up so that you can use ALL 500 channels to receive and transmit on GMRS. Technically it probably does not continue to comply with Part 95 rules, but many of us use it in this opened mode.

If you continue to use it exclusively for Tx on GMRS; I do not see the problem. We open it up to use it on the Ham bands 2 meters and 70 cms and even MURS.

@NC654Which Hex program are you currently using? 4.82 watts would surely make these HTs more usable especially to repeaters! :)

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2 hours ago, MichaelLAX said:

Which Hex program are you currently using? 4.82 watts would surely make these HTs more usable especially to repeaters! :)

I tried to find Hex Fiend and it seems it is no longer available :(  However, I will have a look at Hex-Works possibly over the weekend if I get time.

Trying to locate the power setting could be challenging but that will be after I get the frequency fields changed successfully.

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Take a look at these items in the Code Plug Hex file (through Hex Fiend) for channels 7 & 8 and 14 & 15, where it goes from High power, to Low and then Low to High:

Quote

"7"

      æ¥æ¶é¢ç="462.71250"

      åå°é¢ç="462.71250"

      äºé³è§£ç ="OFF"

      äºé³ç¼ç ="OFF"

      åå°åç="1"

      å®½çªå¸¦="1"

      æ«ææ·»å ="1"

      ç¹å¿éå®="0"

      è·³é¢="0" />

    <ä¿¡éæ°æ®

      ä¿¡éå·=

"8"

      æ¥æ¶é¢ç="467.56250"

      åå°é¢ç="467.56250"

      äºé³è§£ç ="OFF"

      äºé³ç¼ç ="OFF"

      åå°åç="0"

      å®½çªå¸¦="0"

      æ«ææ·»å ="1"

      ç¹å¿éå®="0"

      è·³é¢="0" />

    <ä¿¡éæ°æ®

      ä¿¡éå·=

"14"

      æ¥æ¶é¢ç="467.71250"

      åå°é¢ç="467.71250"

      äºé³è§£ç ="OFF"

      äºé³ç¼ç ="OFF"

      åå°åç="0"

      å®½çªå¸¦="0"

      æ«ææ·»å ="1"

      ç¹å¿éå®="0"

      è·³é¢="0" />

    <ä¿¡éæ°æ®

      ä¿¡éå·=

"15"

      æ¥æ¶é¢ç="462.55000"

      åå°é¢ç="462.55000"

      äºé³è§£ç ="OFF"

      äºé³ç¼ç ="OFF"

      åå°åç="1"

      å®½çªå¸¦="1"

      æ«ææ·»å ="1"

      ç¹å¿éå®="0"

      è·³é¢="0" />

    <ä¿¡éæ°æ®

      ä¿¡éå·=

It goes from 1 1 1 0 to 0 0 1 0; so perhaps one or both of those leading 1's are part of the HIGH power designation.

Oh, but wait, the Programming Software for the T11 already has the HIGH setting for all channels except for 8-14, which are LOW (see my screenshots posted on September 10th).

So maybe some other designator is needed to provide SUPER-HIGH power.

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36 minutes ago, MichaelLAX said:

Try this:

Hex Fiend

It is still offering me an updated version.

I saw that page, but it is for MacOS. Since I'm using Windows 8.1 I had to download Bluestacks and then find the Windows version of Hexfiend, then open it through Bluestacks. The Mac version won't work :(

I did edit the only set of frequencies I found in the T11 software (using Hex-Works) which put the new frequencies in both the TX and RX ?

This may take some time.

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1 hour ago, NC654 said:

I saw that page, but it is for MacOS. Since I'm using Windows 8.1 I had to download Bluestacks and then find the Windows version of Hexfiend, then open it through Bluestacks. The Mac version won't work :(

I did edit the only set of frequencies I found in the T11 software (using Hex-Works) which put the new frequencies in both the TX and RX ?

This may take some time.

Take a look at https://mh-nexus.de/en/programs.php HxD -- native Windows application.

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