Spitfire Build - Pilot Blowing, not glowing!

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Kregg
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Joined: Sun Dec 21, 2008 10:57 pm
Location: Atlanta

Spitfire Build - Pilot Blowing, not glowing!

Post by Kregg »

Alright, I always seem to have a problem on my first fire (especially on the AC side).
The Spitfire circuit (Watts) is my 5th amp build to date.
Usually I blow a fuse (or two), but, today I blew the pilot light.
What steps should I take to track down this problem?
I always use a light bulb limiter. And to my embarrassment, I'm not very knowledgeable beyond the basics with my meter. Sad for a tinkerer I know ... :oops:

[IMG:800:600]http://i141.photobucket.com/albums/r54/crumpred/Amps/IMG_0695_zpsf77f3a46.jpg[/img]
"A man with an experience is never at the mercy of a man with an argument." Hilmar von Campe
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da Geezer
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Re: Spitfire Build - Pilot Blowing, not glowing!

Post by da Geezer »

Looks like you are running the pilot off the mains (120v), correct?

Make sure the bulb is a 120v unit......those type pilot sockets are usually used with 6.3v bulbs and run with the filament/heater supply

G
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Milkmansound
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Re: Spitfire Build - Pilot Blowing, not glowing!

Post by Milkmansound »

yeah - looks like you need to move both leads coming from the pilot lamp mount over to the heaters. Should be a simple fix because you have everything mounted on terminal strips.

Either that, or find a bulb for that mount that runs at 110VAC rather than 6VAC
Kregg
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Joined: Sun Dec 21, 2008 10:57 pm
Location: Atlanta

Re: Spitfire Build - Pilot Blowing, not glowing!

Post by Kregg »

Yeah, 120V.
I'll take another look at the transformer specs.
Thanks

P.S.
It's beginning to look like I need a different lamp/bulb.
Time to hit the books (web).
"A man with an experience is never at the mercy of a man with an argument." Hilmar von Campe
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Ken Moon
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Re: Spitfire Build - Pilot Blowing, not glowing!

Post by Ken Moon »

You could use your DMM to measure the AC voltage directly across the bulb socket. If the bulb is rated for 120VAC, the transformer specs shouldn't matter.

I like to use 120VAC led bulbs that are made for type 47 (BA9S bayonet, also called T1-3/4)) sockets, like these:

http://www.superbrightleds.com/moreinfo ... e-angle/3/

Make sure the bulb is rated for 120 AC volts like the ones I linked to.

Another consideration is that the socket you used might not be rated for 120VAC. The typical Fender style, like it looks like you've used, isn't. These are:

http://www.elightbulbs.com/Sylvania-321 ... Light-Bulb

With your setup, it may be easier to just switch to the heater wires and use a 6.3V lamp. I like to use 120VAC lamps because I can run the pilot lamp right off the Power switch, and avoid running extra wires back and forth from the rear to the front of the chassis:

[img:1014:761]http://i514.photobucket.com/albums/t346 ... wiring.jpg[/img]
Firestorm
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Re: Spitfire Build - Pilot Blowing, not glowing!

Post by Firestorm »

I'm not sure that lamp fixture can handle 120VAC. I think I see burning/arcing on the insulators. IMO, if you want 120V lamps, go Marshall style.
Kregg
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Joined: Sun Dec 21, 2008 10:57 pm
Location: Atlanta

Re: Spitfire Build - Pilot Blowing, not glowing!

Post by Kregg »

Appreciate all of the input and help gents.
Thanks for the links Ken.
I plan on swapping the sockets out, I've found the classic F-style jewel sockets here, http://www.tubesandmore.com/products/P-L110
I should be able to source the T3.25 120V bulbs locally.

I'll post pics when I get the think buttoned up.
"A man with an experience is never at the mercy of a man with an argument." Hilmar von Campe
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