What is the hourly rate for necromancy these days?
Havent decided yet, but it seems like a sought after skill.
If its a Royce, toss it in the dumpster. Junk crap that nobody wants to fix....
I want to. It is a good learning experience.
This is where I am at:
The PLL has it's VCO topping out at 38.5MHz, nothing coming out of the TX test pin, and the LD pin is high suggesting out of lock (which makes sense looking at the VCO frequency).
This is what I believe is supposed to happen....
There are three crystal oscillators in the sardine can. 10.24MHz, 10.695MHz and 36.19MHz. The 10.24MHz crystal goes through a /1024 to make 10kHz for the phase detector during RX and TX. The 36.19MHz signal mixes with the VCO signal (at 37.66-38.1MHz) to create 1.47-1.9MHz for the programmable divider (N=147-191) to make the other 10kHz signal for the PD on both RX and TX. The 10.695Mz signal is mixed with the VCO signal during TX to create the output frequency.
Right now, I have 38.5MHz coming out of the VCO, and nothing coming out of the TX pin. What I do not understand (lacking a schematic) is if the 36.19MHz oscillator and the 10.695MHz oscillator are both dead (scope says so), or if the LD pin is keeping the 10.695MHz oscillator turned off. It uses the M58473P, and I believe those were programmed at the factory for the strange divide by N numbers (they even rearranged the binary input pins at the PLL programmable input pins with respect to the channel selector so it isn't as easy to attack with a switch forcing people to swap mixing crystals instead, dirty rascals lol) and I bet they are very hard to find. I am hoping it is just a dead 36.19MHz crystal.
Looks like I might be taking the sardine can out and drawing a schematic for it. Was hoping to avoid that, but I think many people out there want a schematic for that too. Also, there is a 200Ω variable in the PLL that was maxed out and I have no clue where it should be set without a schematic to offer a hint.