Hey, just a couple quick questions as I didn't see anything like this posted.
I acquired a TK-790 from eBay, (Appears to be a radio that once belonged to Missouri State Highway Patrol) when I got it I opened it up to see if the ignition sense modification had been done, but while I was in there I found something peculiar that I could not find an answer for searching here, Google, or even the service manual.
On the control board there is a 15 kΩ resistor between the EPT (External PTT signal input) pin of C507 and R690. The original R690 and R692 are absent which I could not find a reference table showing both of them removed. I've attached a photo of this resistor. Any input would be helpful.
Now my second question, I know the modification to increase the audio output to 13W has been done, but I can barely get the volume knob off the lowest setting and I'm about blowing my ear drums. I've attached a photo of the maximum I can go with the speaker knob. Im just curious if that's normal with this modification or not. I have the KES-4 speaker hooked up to it. I'll undo the modification if that will help but don't want to waste my time if it won't change anything.
I acquired a TK-790 from eBay, (Appears to be a radio that once belonged to Missouri State Highway Patrol) when I got it I opened it up to see if the ignition sense modification had been done, but while I was in there I found something peculiar that I could not find an answer for searching here, Google, or even the service manual.
On the control board there is a 15 kΩ resistor between the EPT (External PTT signal input) pin of C507 and R690. The original R690 and R692 are absent which I could not find a reference table showing both of them removed. I've attached a photo of this resistor. Any input would be helpful.
Now my second question, I know the modification to increase the audio output to 13W has been done, but I can barely get the volume knob off the lowest setting and I'm about blowing my ear drums. I've attached a photo of the maximum I can go with the speaker knob. Im just curious if that's normal with this modification or not. I have the KES-4 speaker hooked up to it. I'll undo the modification if that will help but don't want to waste my time if it won't change anything.
