Hi Terry -- The main tuning knob quit tuning on my VI+ about 2 years
ago. I called TT service. Tech said to interchange 2 connectors on rear
of front panel to see if rit control would then tune main. I did & it
did. As I remember, it was 55 & 56 or 54 & 55 or possibly but not likely
56 & 57. I ordered and replaced main control.Cost about $45.
Last month in hauling the VI+ in my van, the rit knob was hit, breaking
the plastic shaft. I called TT and was shipped a new rit control for
$13. New one had metal shaft. It was smaller than Main encoder.
Hope this info will help. Good luck.
73, Ariel, k4aal
Terry Zivney wrote:
> I love both of my model 301 remote knobs for
> my two OMNI VI+s. I am considering a modification
> to the OMNI VI which would let me use the knob
> to tune the RIT/XIT.
> In order for this mod to work, I need to know a
> couple of things. First, I seem to recall hearing
> that the encoders for the main knob and the RIT/XIT
> are identical. Is this in fact true?
> Second, the logic board schematic (where the
> encoders terminate) show that both the main
> and remote encoders go directly to the 4077
> XOR chips while the RIT/XIT one goes first
> to a schmidt trigger chip for "cleanup".
> This encoder is also connected through
> pullup resistors to the +5v line, while the
> other encoders are not. Does anyone forsee
> a problem with merely using a 4PDT relay to
> switch the input to the schmidt trigger chip
> from the internal RIT/XIT encoder to the
> external remote encoder? I plan on sensing
> the LOCK led to drive the relay. The underlying
> idea is that when staying on one frequency
> I could LOCK the main frequency and then use
> the external knob to tune in the various callers
> when the RIT control is activated.
> Terry Zivney, N4TZ/9
> TenTec mailing list