Page 1 of 1

HT1250 Modulation Balance Attenuation

Posted: Mon May 04, 2020 11:49 am
by 486dx4
I do not know exactly where to post this question so please correct me if I posted in the wrong place. The question is about some HT1250 radios I was trying to align. I am using the 4460 test box and proper test cables for these radios. I had two HT1250LS+ radios (DP in the model number) where for some reason I am not able to do modulation balance attenuation steps where you put in an audio signal at 80 Hz and 3 KHz and match the deviation at both audio frequencies and certain test RF frequencies. The "DP" (LTR and Passport?) radios I had would not for some reason pass the audio tones to the service monitor to allow you to read the deviation. I did the same test/alignment with a "DU" model radio (LTR) and an "AA" (conventional) model HT1250 and the audio tones come through to allow the deviation to be read by the service monitor so you could adjust. The setup on the 4460, cables, etc were the same for each portable as per what the global tuner software tells you to do in the help section. The portables were either 403-470 or 450-527 models. On the "DP" radios I was able to do all of the other transmitter tests the global tuner software let me do.

Does anyone know what I may be doing wrong? Maybe with the "DP" models the Modulation Balance Attenuation is not needed? The radios did have different slider adjustments in the tuning software so someone must have been able to do this.