Dial light size

4/1/2009 9:34:58 PMJohn

What size dial lights can I put in this RCA model RC1077A. The ones in there don't light and say 3490 on them but what do I replace them with? I only have sizes like 47 and 44. Will the 47's work OK?

4/1/2009 10:24:06 PMEdd

That numbering is supposed to be a # 1490 and is rated at 3.2 V at 160 ma, the two are wired in series and connect across
the 35W4’s pins 4 and 6. . . of which. . . . 6 is a tap off.

POWER DOWN. . . .Use an ohmmeter and see if either lamp is open, otherwise you might have a burnt off #6 tab inside that
35W4Tube.

Nope 47’s are 6.3 at 150 ma

73's de Edd

4/1/2009 10:40:43 PMJohn

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Thanks EDD,

I checked and one lamp is open the other not but what can I use for the burnt out one?

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:That numbering is supposed to be a # 1490 and is rated at 3.2 V at 160 ma, the two are wired in series and connect across
:the 35W4’s pins 4 and 6. . . of which. . . . 6 is a tap off.
:
:
:POWER DOWN. . . .Use an ohmmeter and see if either lamp is open, otherwise you might have a burnt off #6 tab inside that
:35W4Tube.
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:Nope 47’s are 6.3 at 150 ma
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:73's de Edd
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4/1/2009 10:48:33 PMEdd

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:Thanks EDD,
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:I checked and one lamp is open the other not but what can I use for the burnt out one?
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::That numbering is supposed to be a # 1490 and is rated at 3.2 V at 160 ma, the two are wired in series and connect across
::the 35W4’s pins 4 and 6. . . of which. . . . 6 is a tap off.
::
::
::POWER DOWN. . . .Use an ohmmeter and see if either lamp is open, otherwise you might have a burnt off #6 tab inside that
::35W4Tube.
::
::Nope 47’s are 6.3 at 150 ma
::

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A GOOOOOD full service hardware store ACE sometimes have them, otherwise Google it for sourcing and order them.
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::73's de Edd
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4/2/2009 12:05:11 AMThomas Dermody

Norm and possibly Peter know where to get them. Temporarily you can put a #47 in its place.

Do not operate the radio without pilot lamps.

4/2/2009 7:47:51 AMJohn

Where do you guys see a diagram for this set? I know possibly on "techpreservation" but I can't seem to get on that site. Where does Edd get the specs on a 1490 light??

:Norm and possibly Peter know where to get them. Temporarily you can put a #47 in its place.
:
:Do not operate the radio without pilot lamps.
:
:T.

4/2/2009 8:42:07 AMRene

I'm not trying to be a smart-ass but do you know how to use an internet search engine? I use Altavista and when I typed in "1490+lamp" I got lots of hits and the first one was from Donsbulbs.com. The specs were given right there.

:Where do you guys see a diagram for this set? I know possibly on "techpreservation" but I can't seem to get on that site. Where does Edd get the specs on a 1490 light??
:
:
::Norm and possibly Peter know where to get them. Temporarily you can put a #47 in its place.
::
::Do not operate the radio without pilot lamps.
::
::T.

4/2/2009 8:48:09 AMJohn

Well, thanks for comments and searches. I mainly order from RadioDaze and AntiqueElectronics and noticed they don't have any 1490's so didn't look further but now notice that PTOP has them maybe. DO YOU KNOW WHY THOMAS SAYS NOT TO RUN THIS SET W/O THE LAMPS?? I assume it has to do with current drain but not sure about the specifics.

:I'm not trying to be a smart-ass but do you know how to use an internet search engine? I use Altavista and when I typed in "1490+lamp" I got lots of hits and the first one was from Donsbulbs.com. The specs were given right there.
:
::Where do you guys see a diagram for this set? I know possibly on "techpreservation" but I can't seem to get on that site. Where does Edd get the specs on a 1490 light??
::
::
:::Norm and possibly Peter know where to get them. Temporarily you can put a #47 in its place.
:::
:::Do not operate the radio without pilot lamps.
:::
:::T.

4/2/2009 9:06:58 AMnyt

:Well, thanks for comments and searches. I mainly order from RadioDaze and AntiqueElectronics and noticed they don't have any 1490's so didn't look further but now notice that PTOP has them maybe. DO YOU KNOW WHY THOMAS SAYS NOT TO RUN THIS SET W/O THE LAMPS?? I assume it has to do with current drain but not sure about the specifics.
:
::I'm not trying to be a smart-ass but do you know how to use an internet search engine? I use Altavista and when I typed in "1490+lamp" I got lots of hits and the first one was from Donsbulbs.com. The specs were given right there.
::
:::Where do you guys see a diagram for this set? I know possibly on "techpreservation" but I can't seem to get on that site. Where does Edd get the specs on a 1490 light??
:::
:::
::::Norm and possibly Peter know where to get them. Temporarily you can put a #47 in its place.
::::
::::Do not operate the radio without pilot lamps.
::::
::::T.

because the lamps supply current to the plate of the rectifier tube. with no bulbs the tube heater filament must pass all the current and probably blow out in short order

4/2/2009 9:59:15 AMRadiodoc

John,

You may want to check out the RCA model 9Y51, Chassis RC-1077 at:

http://www.nostalgiaair.org/Resources/396/M0015396.htm

Radiodoc
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4/2/2009 11:06:19 AMJohn

I see the diagram now and seems strange to me they would want the set to fail if the dial lights burn out. If the two bulbs are across half of the 35W4 filament then aren't they getting 17.5 volts and they are 3.2 + 3.2 or 6.4 volts or is the 35W4 filament not center tapped as it appears in the diagram? Anyway checked Donsbulbs.com like Rene suggested and he wants $6.90 per. Seems really high for a dial lamp.

:John,
:
:You may want to check out the RCA model 9Y51, Chassis RC-1077 at:
:
:http://www.nostalgiaair.org/Resources/396/M0015396.htm
:
:Radiodoc
:****************
:
:
::Where do you guys see a diagram for this set? I know possibly on "techpreservation" but I can't seem to get on that site. Where does Edd get the specs on a 1490 light??
::
::
:::Norm and possibly Peter know where to get them. Temporarily you can put a #47 in its place.
:::
:::Do not operate the radio without pilot lamps.
:::
:::T.

4/2/2009 4:49:16 PMNorm Leal

Hi John

You are right that pin is a lamp tap and not center tap. Without lamps too much current will be drawn through this section of filament. Your 35W4 will burn out sooner than it should.

I buy bulbs here. A 1490 is 68 cents each.

http://www.bulbdirect.com/products/product.php?item_id=2346&cat_id=

Norm

:I see the diagram now and seems strange to me they would want the set to fail if the dial lights burn out. If the two bulbs are across half of the 35W4 filament then aren't they getting 17.5 volts and they are 3.2 + 3.2 or 6.4 volts or is the 35W4 filament not center tapped as it appears in the diagram? Anyway checked Donsbulbs.com like Rene suggested and he wants $6.90 per. Seems really high for a dial lamp.
:
:
::John,
::
::You may want to check out the RCA model 9Y51, Chassis RC-1077 at:
::
::http://www.nostalgiaair.org/Resources/396/M0015396.htm
::
::Radiodoc
::****************
::
::
:::Where do you guys see a diagram for this set? I know possibly on "techpreservation" but I can't seem to get on that site. Where does Edd get the specs on a 1490 light??
:::
:::
::::Norm and possibly Peter know where to get them. Temporarily you can put a #47 in its place.
::::
::::Do not operate the radio without pilot lamps.
::::
::::T.

4/2/2009 5:06:17 PMRadiodoc

John,

I suspect the reason for the two dial/pilot lamps is the dial scale is probably a long horizontal one and there is a lamp at each end (or therabouts)to illuminate it better than one in the middle of the dial scale. I have an RCA 2-X-61 that uses two 1490 bulbs to illuminate its long dial scale at each end.

Radiodoc
***************

:Hi John
:
: You are right that pin is a lamp tap and not center tap. Without lamps too much current will be drawn through this section of filament. Your 35W4 will burn out sooner than it should.
:
: I buy bulbs here. A 1490 is 68 cents each.
:
:http://www.bulbdirect.com/products/product.php?item_id=2346&cat_id=
:
:Norm
:
::I see the diagram now and seems strange to me they would want the set to fail if the dial lights burn out. If the two bulbs are across half of the 35W4 filament then aren't they getting 17.5 volts and they are 3.2 + 3.2 or 6.4 volts or is the 35W4 filament not center tapped as it appears in the diagram? Anyway checked Donsbulbs.com like Rene suggested and he wants $6.90 per. Seems really high for a dial lamp.
::
::
:::John,
:::
:::You may want to check out the RCA model 9Y51, Chassis RC-1077 at:
:::
:::http://www.nostalgiaair.org/Resources/396/M0015396.htm
:::
:::Radiodoc
:::****************
:::
:::
::::Where do you guys see a diagram for this set? I know possibly on "techpreservation" but I can't seem to get on that site. Where does Edd get the specs on a 1490 light??
::::
::::
:::::Norm and possibly Peter know where to get them. Temporarily you can put a #47 in its place.
:::::
:::::Do not operate the radio without pilot lamps.
:::::
:::::T.

4/2/2009 5:37:50 PMEnd backlit. . .linear dial scale

73's de Edd