[TenTec] OmniVI band info for WARC question

[Ken Brown]

Hi Allan,

You said (in part):

>band output info from the rig but it only
>tells me 40/30, 17/15, etc. Has anyone worked out a way to
>get separate band info for all the bands or perhaps a
>single output to tell whether the WARC  or  'contest band'
>choice has been made. 
>
The BPF/Front End Board (81593) is where the complete 9 parallel line 
band information coming into connector 86 gets diode matrixed 
(D1,2,3,4,5,6) into the reduced 6 parallel lines and comes out connector 
14. These 6 parallel lines go to the Low Pass Filter Board (81592) and 
pass through it, on to connector 8. A cable from connector 8 goes to the 
TX Audio / BFO Board (81597) which has the 25 pin RS-232 connector on 
it. There are plenty of spare pins on this connector. I think it would 
be fairly easy to tack three more diodes onto the 12, 17 and 30 meter 
lines on the 81953 board and tie them together to make a "WARC Band 
Status Indicator" line that feeds a previously unused pin on the RS-232 
connector. You could then use this line to control a "Amplifier Disable 
on WARC bands logic gate".

There are other places before the 81593 board you could pick off this 
information. Perhaps some of the other places are easier to get to. 
Check out the Model 563 Wiring Diagram which shows the interconnections 
between all the boards. You might also want to bring all of the 9 
parallel lines, or even the 12 parallel band lines ( where 10 meters is 
four bands) out and do the matrix outside the radio. You can find these 
lines on the wiring diagram too. I see enough unused pins on the RS-232 
connector that you could do this.

If you do any of these things I recommend you include series current 
limiting resistors and also probably some little inductors such as you 
see on the 81592 board. This will help to keep digital noise and smoke 
inside the radio that might otherwise get out when you add these new 
lines. Also the unused pins on the RS-232 connector may be connected to 
wires in your interconnecting cables, which aren't doing anything now 
but might cause trouble after the modification. Make sure your RS-232 
cables only have the wires you are really using if you decide to use 
some of these presently unused pins.

Good luck and have fun,

73 DE N6KB