Bringing up another old thread i know, But i would like to add something to this modification if anyone ever wants to try it.
I wanted to mod one to 10m band with freq ending in zero, So i did the mods as explained by Clint [However i had to leave the original cap in C72] and i used a 16.260 crystal and aligned radio for 27.865 to 28.305, But then i swapped PLL to a UPD2816 and grounded pin 9 [T/R] and it jumped to 28.320 to 28.760, I also unlocked clarifier and it has quite a bit of slide, But i found that 28.500 fell into an alpha slot, So i replaced the 16.260 for a 16.385 i had lying about and it now does 28.450 to 28.890 with 28.500 being on Ch 5
But what i would like too add is i found out an external 10.240 oscillator board isn't really needed, A 10.240 crystal can simply be soldered directly to the RI and RB pins of the PLL [Pins 13 and 14], This makes modding an AR144/146 to Say High band with a 15.810 alot easier [No need to swap PLL if modding for High band]
Just thought i would share this if anyone wanted to mod an AR144/Cobra 146.