"Peebles Originals" PO-103 Antenna Tuner

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 ANTENNA TUNER ROTARY SWITCH 
 
Peebles Antenna Tuner
The ingeniously connected rotary switch.
 

 
Peebles Antenna Tuner

What is going on with the switch on the antenna tuner? I'm trying to visualize it mentally, but I'm having trouble. When the switch is in position 1, terminal 2 of switch A is connected to terminal 1 of switch A, which is connected to terminals 2,3,4,5 and 6 of switch B. What does that do?? This is blowing my mind.

Below are equivalent schematics with the switch in position 1, 2, 3 and 6 which give a clearer idea of how it works.


 
 SWITCH IN POSITION 1 
 
 
Peebles Antenna Tuner
 
Peebles Antenna Tuner
 
If we remove the switches while they are in position 1, the circuit looks like this. Much easier to visualize!
 
Peebles Antenna Tuner
Moving the capacitors in the schematic gives a clear picture of them in parallel with the coil.
 

 
 SWITCH IN POSITION 2 
 
 
Peebles Antenna Tuner
 
Peebles Antenna Tuner
 

Position 2 is selected. Notice that switch A is now connected to nothing at all. If we remove the switches, we see that the capacitors are now in series with the coil. They've gone from being in parallel to being in series with a single turn of the switch!


 
 SWITCH IN POSITION 3 
 
 
Peebles Antenna Tuner
 
Peebles Antenna Tuner
 

Position 3 is selected. Since all the terminals on switch B are connected together, we can remove it in the drawing. On the right, we have also removed switch A so we can see what the circuit looks like. Switch A has shorted out 60 turns of the coil, making a 40 turn coil.


 
 SWITCH IN POSITION 6 
 
 
Peebles Antenna Tuner
 
Peebles Antenna Tuner
 
Position 6 is selected. Switch A has shorted out 95 turns on the coil, making a 5 turn coil. On the right we see the circuit without the switch.
Positions 5 and 6 are used for shortwave.
 

 
 Connecting The Switch 
 
Peebles Antenna Tuner
The switch in the instructions probably won't match any switch you can buy today. So how do you connect it?
 
 
Peebles Antenna Tuner switch
 
Peebles Antenna Tuner switch
 

It's actually not hard to do. Obtain a 2 pole 6 position switch. Select which side will be Switch A and which side will be Switch B. Use an ohmmeter to find terminal 1 of each side, and mark them. (Make sure the switch is turned fully counter-clockwise to position 1). Then just follow the drawings in the instructions. It will be easier to wire if you make the connections shown on the right before installing the switch.

Don't forget, you're looking at the back of the switch, so the numbers will be counter-clockwise.

 

 
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