Kustom Defender 5H Power Switch and pilot light

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jonjlw
Posts: 3
Joined: Sat Sep 28, 2013 1:35 pm

Kustom Defender 5H Power Switch and pilot light

Post by jonjlw »

Hello, all - First time poster. My interest in music electronics far outweighs my ability, so patience is appreciated. :)

Here is the project: Take a 40's era Philco radio and convert it to a low watt guitar amp. To make it easy on myself, I bought a Kustom Defender 5 watt for $100. My plan is to remove the input and volume control from the circuit board so that I can solder in leads that will enable me to relocate those components to the holes where the old controls were previously located on the front of the radio. Then I just need to secure the amp inside the cabinet...put in a 12" celestion and I'll be in business. But I want to do one more thing. I want to backlight the dial when I turn it on so it still looks like it's a radio. To do that, I want to locate a pilot light or panel light inside the cabinet. The Defender comes with a lighted rocker switch (no standby)...switch lights up in the On position. AC to switch: yellow to ground; red to switch; blue/white- blue to switch and white to power transformer. Black from switch to power transformer. Here is a schematic: http://www.rh-tech.org/public/Kustom_De ... H_RevB.png. And here is shot of the inside http://i239.photobucket.com/albums/ff83 ... der009.jpg. Ideally, I'd like to find a rotary on/off switch just like the radio probably had. When I turn it on, the pilot light backlights the dial. Doable? If so, how. I don't know what kind of switch I'm looking for either.

I hope this is all clear. What other info can I provide. Would so appreciate your help. Thanks! Jon[/url]
rock_mumbles
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Location: Podunk, Idaho
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Re: Kustom Defender 5H Power Switch and pilot light

Post by rock_mumbles »

Be careful pulling the input jack and volume pot from the pcb ... it's easy to damage the pcb ... I usually destructively remove them so each lug soldered to the pcb is removed one at a time ...

In a radio or vintage amp the indicator lamp was a 6.3V 'flashlight lamp' ... depending on how bright they are they can draw almost as much current as a 12AX7 ... in the KD5H I don't think you have a lot of excess 6V current ...
in the Kustom amp switch I think they are using a 120V neon lamp.

I'd probably use white LED's which don't require much current ... they would be powered off of the 6.3V filament supply and require a current limiting resistor so the LED doesn't burn out ... see if you can illuminate the edge of the glass or plastic 'plate' ...
jonjlw
Posts: 3
Joined: Sat Sep 28, 2013 1:35 pm

Re: Kustom Defender 5H Power Switch and pilot light

Post by jonjlw »

Thanks for the reply. So far, so good. Components pulled, leads wired. I'm still alittle confuse about the 6.3v vs 120v reference. But I think all I need to do is get a 120V LED with a resistor and then figure out where I'm going to mount it. Good idea to light the edges.

I mentioned that there were 3 wires going into the switch - red, black, blue. I learned that the blue one powers the light. Can I assume that one lead of the LED (with resistor) attaches to that and then I'll have to find a ground for the other? Is that how it works?

Thanks a bunch. I can see the end in sight. jw
rock_mumbles
Posts: 244
Joined: Mon Nov 17, 2008 2:03 am
Location: Podunk, Idaho
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Re: Kustom Defender 5H Power Switch and pilot light

Post by rock_mumbles »

Something I forgot is LED's don't like AC voltage so you'll need to put a diode in circuit as well as a current limiting resistor ... you can use two LEDS wired in parallel but opposite to each other or a power supply diode wired parallel in reverse to the LED ...
google AC powered LED

Most LED's operate on about 2V ... so with any supply over that you'll need to calculate the necessary current limiting resistor there are online calculators
jonjlw
Posts: 3
Joined: Sat Sep 28, 2013 1:35 pm

Re: Kustom Defender 5H Power Switch and pilot light

Post by jonjlw »

Perfect. Love learning this stuff. Thank you, jw
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