Ed, No external fixing, all internal just like the original. The 'Parts Lists Amendment' states the alternative IC700 frequency reference is used in -16, -26, -36 for FCC I think it differs from the standard by having 4 pins, one of which is the FM pin with the voltage setting arrangement. Other IC700's didn't have that. Let me check again at work today, it 6AM and I am on my way to the salt mine.
Al --- In [email protected], Ed Yoho <w6yj_ya...@...> wrote: > > niteviser wrote: > > OK Ed, > > > > I have 2 files showing the PCB details with -26 variant info. They > > frequency reference is still kept totally internal. If higher stability or > > external reference is available, the internal is removed and a mini coax > > socket fitted to have a cable connected to have an input on the rear panel. > > I will put the pdf files in the files section. Look for T857 > > 220-01398-02_-04.zip. > > > > Al (niteviser) > > > > Al, > > Thanks for the PDFs. > > Can you tell me where/how the "FM" (tuning voltage) is brought out on > the -26? I looked and both the -02 and -04 variants show the FM pin on > the VCXO tied to 2.5V and AC coupled to REF-MOD. For the life of me, I > cannot find a DC path that would allow for external frequency shifting. > If the -26 still has the resistive divider and nothing else loading the > FM pin, just ignoring the tuning voltage path should work fine (as a -20). > > Other than that, it appears only a few resistor and capacitors are > different from a -25 to comply with frequency mask compliance and these > would need to be changed anyway to make it a -20. > > Ed Yoho > W6YJ >
