So as a new tech I am still learning to repair radios. I am working on a 148gtl side mic that was not functioning when I got it.
The pll was out of lock and I traced it back to the 11.325 crystal. I was getting no frequency from it all. Replaced it and pll locks!
Moving on with the alignment I get to where I check ic3 pin 7 on Christmas 19am for 7.8mhz, radio is dead on 7.8. Check either side band for offset and frequency fluctuates between 5mhz and 11mhz.
I am testing with a 30db wideband, now noise rf amplifier (can be seen in a video by mikesradiorepair) in line to my counter and a 10x probe.
Also I get a humming/buzz on recieve and transmit on am. The radio keys 4watts and swings to 10watts on am. Receive is dead quiet unless I am transmitting from another radio on the same antenna switch, no static at all.
I just got it to this point so I haven't gotten too far into diagnosing these issues yet, but t hopefully I can learn something from this post!
Edit: forgot to add, this radio is bone stock and clean inside!!
The pll was out of lock and I traced it back to the 11.325 crystal. I was getting no frequency from it all. Replaced it and pll locks!
Moving on with the alignment I get to where I check ic3 pin 7 on Christmas 19am for 7.8mhz, radio is dead on 7.8. Check either side band for offset and frequency fluctuates between 5mhz and 11mhz.
I am testing with a 30db wideband, now noise rf amplifier (can be seen in a video by mikesradiorepair) in line to my counter and a 10x probe.
Also I get a humming/buzz on recieve and transmit on am. The radio keys 4watts and swings to 10watts on am. Receive is dead quiet unless I am transmitting from another radio on the same antenna switch, no static at all.
I just got it to this point so I haven't gotten too far into diagnosing these issues yet, but t hopefully I can learn something from this post!
Edit: forgot to add, this radio is bone stock and clean inside!!