Nitro knobs Installation

[gohusan]

Can anyone help me in regards to installing some Nitro knobs into my Cobra 148 GTL. 8) I've looked under the the topics & read they can short out if touching some metal part :shock: ; & was wondering if anyone has installed some who may have some pic's to show how to avoid such a catastrophy. 2nd I've also read to supply the power from the regulator and to ground to something clean; but what is the regulator in the radio & where would a clean ground be? :?: Also, should I set the knobs in series or is it preferable to have them in a parrallel circuit. One final thing that hopefully should not cause any problem; Putting a SPST switch in the circuit will allow me to turn the knobs on & off but should not affect anything hooked up to the regulator right? :?:

Thnx

 

[gohusan]

OK, the Nitro Knobs are installed by a guy I know who fixes radio.

The only problem is that the lights in the knobs are really bright:

is their a way I could dimm them a bit buy adding a resistor in line.

 

[74IN]

Yep.

 

[gohusan]

Thanx; really appreciate the link

 

[Krazzy-K]

install of nitro knobs on galaxy 959 with dimmer knob

hey 74IN you seem real knowledgeable on these nitro knobs. i have a question for you or anybody that can help me out. i have a galaxy 959 dx radio which i love dearly. its all blued out except the knobs. well my question is when i hook up the nitro knobs do you think i could hook them up to the dimmer circuit,or do you think i will have to add a switch? sorry my knowledge is next to none on these knobs.but i think they look good. i have some on order.any help would helpful.

thanks
73's

 

[zygoma]

Each knob has (I think) 3 mini-LEDs inside, so 2 knobs will be 120 mA more draw on the source, or about a quarter-watt. I'm sorry that I don't know if your radio has a pot or a toggle for a dimmer.
To be safe, I'd limit the current to the LEDs a little by putting a 1/4-watt, 100-ohm resistor in series with the line to the Nitro Knobs. I don't know how much current the stock dimmer's circuit should be able to supply, so this will help limit the extra load a little bit. If it seems the Nitro Knobs are substantially dimmer than the other panel lamps, go to a little smaller value resistor, but remember that more current will make the resistor dissipate more heat, so if you go to a 56-ohm resistor, you might need a 1/2-watt resistor to keep it from burning up.
I recently took a Cobra 29 BT in on trade, that had a full panel of blue Nitro Knobs. I'd never seen them live, and I foolishly plugged it in on my bench without a welder's hood, and nearly went blind.
Of course I'm exaggerating, but these things, along with the stock blue lights on the meter and chanel selector, put out enough light to read with in the front of my van. They're wired in parallel, straight from the power switch to ground. I'm playing with resistor values now to find a good level to make the knobs visible without leaving a row of big black spots in front of everything I look at for the next 15 minutes....
-- Zygoma --

 

[radiorebel29]

Could u add nitro knobs into a dimmer switch? Like on my cobra 29 could I replace Delta tune and make it s dimmer?

 

[Robb]

Bet that radio sounds even more garbled on SSB with those lights drawing that much more current from that already poor/miserable and overtaxed 9V voltage regulator.

Clearly this radio being used for AM only.
These new 148's are already massively anemic in the SSB department.
BTW - no amount of upping the radio's input voltage will help that situation out either . . .