1. A Simple, Four-Band IF/Transverter Switch
By Jim Aguirre (W7DHC)

2. The problem… One IF rig Multiple transverters
Needed “fool-resistant” switch for rover use

3. The solution…

4. A view from the back…

5. and, from the top…

6. Background
I tried several switch approaches in the rover rig with mixed results

7. Background
I tried several switch approaches in the rover rig with mixed results
I needed to switch both RF & PTT line at the same time to avoid “operator error”

8. Background
I tried several switch approaches in the rover rig with mixed results
I needed to switch both RF & PTT line at the same time to avoid “operator error”
N7CFO found that the CS-401 had a 30° throw like many common rotary switches

9. Background
I tried several switch approaches in the rover rig with mixed results
I needed to switch both RF & PTT line at the same time to avoid “operator error”
N7CFO found that the CS-401 had a 30° throw like many common rotary switches
The rest is history. An IF switch is born!

10. The heart of it all…
…a Daiwa CS-401 coax switch

11. Father and son…

12. A CS-401 with BNCs?
Most transverter IF inputs are BNC, so I thought BNC connectors would be a plus.
Rumor has it that Daiwa once produced such a version of its CS-201/401 switch. I doubt it!
I modified my CS-401 by removing the original SO-239 connectors, making adapter sleeves and installing BNC chassis-mount connectors.
You can use PL-259/BNC adapters on a stock switch for the same end result

13. Pretty simple inside…

14. Another inside view…

15. The only tricky part…

16. IF rig PTT outputs… IC-706MkII ACC has H-Send & V-Send pinouts
Use V-Send for 144 MHz IF transverters
Use H-Send for 28 MHz IF transverters
Other IF rigs will have different PTT outputs
Use reed relays to do actual PTT keying

17. IF rig connections…
From the IF rig, pick up… - PTT line output(s) VDC for the reed relay - Ground

18. Suggested parts list… Daiwa CS-401 coax switch
4-position rotary wafer switch with 30° throw + knob
¼-inch shaft coupler
Small enclosure (Hammond 1590D or equiv.)
2 ea. 12 VDC reed relays (RS )
2 ea. 1N4001 diodes or similar (if needed)
#18 hook-up wire
5-pin mini-DIN jack
4 ea RCA jacks (or 5 with extra 28 MHz output)
2 ea. #8 FH machine screws & nuts
2 ea. 1.5” tubular spacers or tapped standoffs

19. Any questions?
See my article in the 2005 PNW VHF Conference “Proceedings” for additional information on this project
That’s it! Any questions?