Yaesu Quadra Manual Band Switch

The Yaesu Quadra VL-1000 HF Amplifier has the ability to have 2 radios connected to it independently.  Each input has an RF connection, PTT , ALC control and band switching.

In my situation I use my Icom IC-756pro3 on input 1 and band switching is achieved using my Icom (CI-V or band Data) to Yaesu BCD Band Data Converter to convert the IC-756pro3 band data (CI-V or voltage) to Yaesu BCD which switches the Quadra band automatically.  This left port 2 available to other radios and as the Quadra does not have UP/DOWN band switches on the control panel I needed a way to do do band switching externally when a radio was connected t this port – due to my experimenting nature this radio could be anything for an SDR to an FT-817.

Talking with William M0ZXA he had a similar issue at G6UW and so he done a quick first pass a coding something using an 8 pin PICAXE-08m2 which could control the Quadra band using simple [BAND] UP and DOWN buttons. I optimised the code slightly to reduce the number of actions and added some additional code for switch de-bounce ‘protection’.


William also provided me with pre-built circuit in a box with 2 buttons ([BAND] UP and DOWN) with a lead terminated in a 15 way D-Sub used for for the Radio 2 input on the Quadra. Unfortunately there is no +v output on the Quadra so you also need provide a separate +12v, or +5v, input.

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The inside showing the circuit.  No programming components were included (R1, R2 & J1) allowing for a smaller footprint.

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NOTE: This design will not work with a non M2 PICAXE-08 part due to the lack of ‘DISCONNECT’ support for the Serial In pin (pin 2) to allow it to be reassigned to a input.



Download the schematic (ExpressSCH) and PICAXE code.

#PICAXE-08m2	' Required, as the serial in pin is repurposed as an input.
OUTPUT 0,1,2,4

SYMBOL Band   = B0
SYMBOL Old    = B1
SYMBOL Quadra = B2

Manual band select controller for Yaesu Quadra VL-1000, by M0ZXA and M1BXF

Disconnect		' Disconnect the programming pin so it can be used as an output
read 0,Band		' Load the last band used on power-up from the eeprom in BAND
If Band > 10 then	' This if statement is to catch an invalid value loaded from the eeprom
 Band = 10		
goto Change_Band	' On power up goto the Change band routine to configure the pins to the eeprom value
' To reverse the UP and DOWN buttons, switch the SYMBOLs UpBand & DnBand at the top.
If UpBand = 1 then: Inc Band: Endif	' Increment band
If DnBand = 1 then: Dec Band: Endif 	' Decrement band

If Band = 11  then: Band = 00: Endif 	' Have we gone past the Highest band? If so change to lowest band
If Band = 255 then: Band = 10: Endif	' Have we gone past the Lowest band? If so change to Highest band

If Band <> Old then goto Change_Band	' If BAND doesn't match the OLD [BAND] value update the PINs

goto main				' We didn't see any changes so Loop back to MAIN to see if a button is pressed	

					' Select the band BCD from the appropriate position
Lookup Band,($01,$02,$03,$04,$05,$06,$07,$10,$11,$12,$17),Quadra	
Pins = Quadra				' Make the output pins match the band data.
Old  = Band				' Make Old = Band for checking for changes later.
	write 0,Band			' Save chosen band to eeprom
hold:	if pin5 = 1 or pin3 = 1 then	' Require button to be released
	 goto hold			' Loop while the button is still pressed
	pause 100			' De-bounce
	goto main

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