Panasonic RA-6600 need lamp help & info

On Wed, 11 Jul 2007 23:22:53 GMT, wrote:

wrote:
Now I just need to figure out the wattage and voltage.

In these latter days, I've only ever seen a choice of voltages, not
powers in each voltage. However,
http://www.donsbulbs.com/cgi-bin/r/t...x=0&bclick.y=0
shows that at one point, they seemed to exist at three power levels at
each of 6, 6.3, 8, and 12 V.

Voltage across the lamp clips is 11 VAC.

With that information I'd guess a 12 V lamp, deliberately fed a low
voltage to decrease the brightness but increase the life. A second
guess would be a really high-impedance (low current) unregulated
supply that is drifting up to 11 V with no lamp load, but that sags down
to 8 V or 6 V when loaded by a lamp. snip

Usually, these are fed from just a winding off the transformer,
usually a nominal 12V that's usually lower, as you say, to extend
filament life. You're also right that finding different filament
resistances for each rated voltage is nigh impossible now..."one size
fits all!"

One way I get around incandescent panel and indicator lamps these days
is with white LEDs. Sometimes the color is disturbingly "blue-white,"
but they do not load the supply at all and last forever. Many old
incandescents, like the old 386/357 panel indicators, now have direct
LED replacements in a multitude of colors. Many common bayonet styles
also now come in LED replacements, as well.

This was a long time coming, actually. Western Electric started
selling its captive customer telcos LED-based A1 and A2 switchboard
lamps (wedge based, jackfield mount) back in the late '70s! They
weren't too bright back then, though, but they were permanent.

I doubt the local library will carry Sams, but I'll give them a try.

This guy http://www.agtannenbaum.com/p_cat.html says he has (presumably
a copy of) the service manual for $20.

I'd just buy-and-try, but prices for the fuses seem to be all over
the place from 45 cents ea. (10pk) to $6.50 ea. plus ship!

You might sneak down to the car parts store and see if they have some
#73 (14 V, 1.1 W) or #74 (14 V, 1.4 W) wedge-base lamps. Get one and
use clip leads to hook the lamp across the fuse holder clips and
evaluate the brightness. Also measure the voltage with the lamp in
place. If it's reasonably north of 10 V, and if the lamp looks like
it's bright enough to light up everything it needs to, then a 12 V
fuse lamp is a good bet. If the voltage is north of 10 V but the lamp
isn't bright enough, you might move up to a 160/161 (14 V, 2.7 W), 158
(14 V, 3.4 W) or maybe even a 194 (14 V, 3.8 W) lamp and try that. If
the voltage stays over 10 V and the lamp is bright enough, then try a
12 V fuse lamp first. If the voltage is way under 10 V with a #73 or
#74 connected, you might try an 8 V fuse lamp first.

None of the lamps I've mentioned are a direct replacement for the fuse
lamps - they don't fit mechanically and the filament is not nearly as
long, so it won't work as well with whatever reflectors or light pipes
the stereo might have. However, you can buy them at 8 PM on Sunday at
any car parts store and maybe even at Wally World. They're also easy to
use without an "official" socket. If you're feeling really thrifty, the
73/74 types are often used as instrument panel and switch illumination
in cars, while the 160/161/158/194 show up in side marker and parking
lights. (Note: Only 'borrow' lamps from your own car to feed your
8-track habit. Your neighbors might not understand why you're prowling
around their car with a screwdriver at 11:30 PM.)

Standard disclaimers apply; I don't get money or other consideration
from any companies mentioned.

Matt Roberds

Just a followup...Got a 12V 150ma fuse lamp from PartsExpress.com and
works fine. Could be a little bit brighter, but for less than $1.50
delivered I'm very happy. Thanks for the tips in this forum.