In your GTX RSS folder, there should be a readme.txt file. Inside that should see something like this...
The Motorola GTX Radio Service Software (RSS) for Privacy Plus / LTR
currently supports these Models:
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10 Trunk Systems x 8 Groups/Sys (80 Trunked Modes), 10 Conv. Channels.
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"Standard" Full-Feature Models; Portables have Keypad -and- Display.
M11UGD6CB1_N - GTX MOBILE, 800 MHz, 15 Watt, Privacy Plus.
M11WGD4CB1_N - GTX MOBILE, 900 MHz, 12 Watt, Privacy Plus.
H11UCD6CB1_N - GTX PORTABLE, 800 MHz, 3 Watt, Privacy Plus.
H11WCD4CB1_N - GTX PORTABLE, 900 MHz, 3 Watt, Privacy Plus.
M11UGD6CU1_N - GTX MOBILE, 800 MHz, 15 Watt, LTR.
M11WGD4CU1_N - GTX MOBILE, 900 MHz. 12 Watt, LTR.
H11UCD6CU1_N - GTX PORTABLE, 800 MHz, 3 Watt, LTR.
H11WCD4CU1_N - GTX PORTABLE, 900 MHz, 3 Watt, LTR.
"Standard" Full-Feature "High-Power" MOBILES:
M11UGJ6CB1_N - GTX MOBILE, 800 MHz, 35 Watt, Privacy Plus.
M11WGJ4CB1_N - GTX MOBILE, 900 MHz, 30 Watt, Privacy Plus.
M11UGJ6CU1_N - GTX MOBILE, 800 MHz, 35 Watt, LTR.
M11WGJ4CU1_N - GTX MOBILE, 900 MHz, 30 Watt, LTR.
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4 Trunk Systems x 3 Groups/Sys (12 Trunked Modes), 4 Conv. Channels.
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"BASIC" Models; Portables have -NO- Keypad, -NO- Display.
H11UCC6DB1_N - GTX PORTABLE, 800 MHz, 3 Watt, Privacy Plus.
H11WCC4DB1_N - GTX PORTABLE, 900 MHz, 3 Watt, Privacy Plus.
H11UCC6DU1_N - GTX PORTABLE, 800 MHz, 3 Watt, LTR.
H11WCC4DU1_N - GTX PORTABLE, 900 MHz, 3 Watt, LTR.
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Now check your readme file and see if your model is in there. It is listed in my file, but if it isn't in yours, you do not have the right software. Post a picture of your programming setup, RIB and cable.