Buttfuzz:
You have to have anywhere from 3.65-4.2V (or roughly 1/2 VCC) to pin 10 to get the +192 state. That's why I made a circuit with a LM7805 and a 3.6V 1W zener diode, with a couple caps and a variable resistor, to dial in the 1/2 VCC necessary to get the +192 to work. I incorrectly stated that in my previous post as N+128, when I meant to say N+192 as stated by NZ8N. (Thanks to NZ8N for that corrrection.)
However, starting with the Malaysian radios, they started doing away with the Fujitsu MB8719 PLL IC's, and started going with "copies" of that PLL. Some of these radios have an MMB8719, and some of them also had some early variants of the RCI8719 PLL.
When trying to mod the newer PLL's for N+192, it will not work, as the silicon substrate "setup" in the PLL is not the same as the old Fujitsu PLL's. That being said, in testing the MMB8719's simply will not toggle both N+64 AND N+128. it will only toggle one, depending on voltage. On the early RCI8719 variants, if you tried this method, you'd destroy the PLL by "damaging" pin 10 so it is no longer useful. That's likely why it didn't work on your "The Malaysia" radio.
This N+192 method will ONLY work on the Fujitsu MB8719's.
(Edit) Also, NZ8N also brought up a good point about R95. Changing that value slightly will improve bandwidth "reach" to where you can lock the N+192 channels.
~Cheers~
