Please explain how the Ch 9 / Ch 19 switch operates?

[jimbowilly]

Hi, I found a Cobra 29 Ltd Classic at a local garage sale. The Ch9/Ch19 Switch of the Cobra 29 Ltd is broken and will not stay in the up position. Can I just solder the 2 - black and yellow wires together?
Thanks,

 

[brandon7861]

I thought "up" was ch19, middle was ch9 and down was NORmal mode. Never seen one where "up" was the NOR position. Is your radio installed upside down, or do you really like ch19?

The NOR position provides the ground for the channel knob. Taking the switch off the NOR position removes the ground from the channel knob and, via diodes, applies ground to the ch9 or ch19 logic lines directly.

So the answer to your question really depends on what "up" means. In the case of keeping it in normal mode, the wires at the NOR position must be tied together and the other wires must be isolated from the switch and each other (otherwise the switch will make loose contact with the ch9/ch19 positions and do strange things at the PLL). Hot glue might work if its just a dusty old work radio.

 

[jimbowilly]

This is a 6 pin dpdt switch. Black on middle pin routed to PCB ground. Yellow on top pin routed to Channel Selector PCB.

I did find a previous post, "Cobra 29 Switches" , addresses the elimination/repurposing of the Ch9 Switch.

 

[brandon7861]

I think its worth a try

 

[jimbowilly]

The Yellow and Black wires connected together changes the radio to Ch 9. So I left the Yellow and Black wires connected to the pcb and taped and shrink tubed the ends which I removed from the switch separately.

 

[Uncle Ronnie 336]

i like repurposing them for other mods myself

 

[jimbowilly]

i like repurposing them for other mods myself

With this radio being from 2021, the dpdt switch, in the Ch9 switch location, only uses 2 wires. A yellow wire - top pin of switch to the Channel Selector pcb. And a black wire - center pin of switch to pcb ground.

Also, with the 2021's model of the Cobra 29 Ltd Classic.
-Soldering the yellow and black together puts this radio on Ch9.
-Separating the yellow and black puts this radio on 40 channels.

 

[Uncle Ronnie 336]

sounds like the perfect easy conversion for something like an echo mod or a diode-switched channel kit oscillator

 

[jimbowilly]

sounds like the perfect easy conversion for something like an echo mod or a diode-switched channel kit oscillator

I replaced the Ch9/Ch19 switch with the on/off switch for a RM Italy AD 203 PCB Stinger Board. I also replaced the Delta Tune knob with the dual control knob for a TRB-X3 echo board. And, I ordered a new faceplate which has the replaced controls lettered accordingly.

 

[Uncle Ronnie 336]

I replaced the Ch9/Ch19 switch with the on/off switch for a RM Italy AD 203 PCB Stinger Board. I also replaced the Delta Tune knob with the dual control knob for a TRB-X3 echo board. And, I ordered a new faceplate which has the replaced controls lettered accordingly.

i like to use the PA switch for stingers or rfx units because it goes from "public address" to "power amp"