[stan]

I was fortunate enough to pick-up a Pioneer SX-3700 on eBay recently without
any burned-out bulbs - which is pretty amazing considering the unit was 28
years old and has no less than 11 bulbs inside! Imagine my dismay when,
after using DeoxIT to clean the noisy switches and pots, then reassembled
the unit only to find I had somehow broken two of the bulb filaments while
working on the receiver.

The required bulbs with leads can be purchased through eBay, but not wanting
to wait for the auction to end, in addition to the shipping delay, I thought
I would take a chance with a wired bulb that is readily available from a
nearby Radio Shack. The service manual calls for an 8V; 50 mA bulb, whereas
the closest Radio Shack equivalent is 6V; 25 mA (cat no. 272-1140). Since
the bulbs were only $1.49 each, I wouldn't be out too much money if they
didn't work, either. I snipped-off the old bulbs near the base of the bulb
with wire cutters, then soldered the new wired bulbs with a ¼-Watt; 100-Ohm
resistor in series, to drop the higher supply voltage to match the
requirements of each replacement bulb. You'll need to thread the leads of
the new bulb through the plastic holder before soldering, since the bulb is
too "fat" to be slid up through the back end of the plastic lamp holder. I
wrapped the soldered leads individually with electrical tape, including the
entire resistor and all conductive surfaces to avoid any potential arcing
with other nearby circuitry - ideally heat-shrinking insulation would
probably be a better choice if you have it available.

Also note that the bulb diameter is just a hair larger than the
factory-installed bulb - this shouldn't be a problem, though. The bulb
holder spreads-out from the back-end to the front-end, so the bulb will seat
a bit farther forward - but not so much that it would protrude beyond the
face of the holder. In my opinion this is an advantage, since it increases
the visible luminescence of the replacement bulb - while it consumes half
the current of the bulb it replaces, the brightness seems comparable to its
surrounding siblings.

So if you have a Pioneer SX-3500/3600/3700/3800/3900 with burned-out bulbs,
and you also have a soldering iron, with a bit of care and patience you too
can fix them today!

[Tzortzakakis Dimitrios[_2_]]

Ï "stan" Ýãñáøå óôï ìÞíõìá
...
I was fortunate enough to pick-up a Pioneer SX-3700 on eBay recently
without any burned-out bulbs - which is pretty amazing considering the unit
was 28 years old and has no less than 11 bulbs inside! Imagine my dismay
when, after using DeoxIT to clean the noisy switches and pots, then
reassembled the unit only to find I had somehow broken two of the bulb
filaments while working on the receiver.

The required bulbs with leads can be purchased through eBay, but not
wanting to wait for the auction to end, in addition to the shipping delay,
I thought I would take a chance with a wired bulb that is readily
available from a nearby Radio Shack. The service manual calls for an 8V;
50 mA bulb, whereas the closest Radio Shack equivalent is 6V; 25 mA (cat
no. 272-1140). Since the bulbs were only $1.49 each, I wouldn't be out
too much money if they didn't work, either. I snipped-off the old bulbs
near the base of the bulb with wire cutters, then soldered the new wired
bulbs with a ¼-Watt; 100-Ohm resistor in series, to drop the higher supply
voltage to match the requirements of each replacement bulb. You'll need
to thread the leads of the new bulb through the plastic holder before
soldering, since the bulb is too "fat" to be slid up through the back end
of the plastic lamp holder. I wrapped the soldered leads individually
with electrical tape, including the entire resistor and all conductive
surfaces to avoid any potential arcing with other nearby circuitry -
ideally heat-shrinking insulation would probably be a better choice if you
have it available.

Also note that the bulb diameter is just a hair larger than the
factory-installed bulb - this shouldn't be a problem, though. The bulb
holder spreads-out from the back-end to the front-end, so the bulb will
seat a bit farther forward - but not so much that it would protrude beyond
the face of the holder. In my opinion this is an advantage, since it
increases the visible luminescence of the replacement bulb - while it
consumes half the current of the bulb it replaces, the brightness seems
comparable to its surrounding siblings.

So if you have a Pioneer SX-3500/3600/3700/3800/3900 with burned-out
bulbs, and you also have a soldering iron, with a bit of care and patience
you too can fix them today!

What do you mean by bulbs, vacuum tubes? If yes, you probably mean the
filament voltage? Are you sure you got the same tube? They have a type
number, eq like 807 or 6C4, the usual specs a working frequency, plate
voltage, negative bias for control grid and possible screen voltage.
Usually, they have also a pin layout. There used to be thousands of vacuum
tubes.


--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr

[Mark D. Zacharias[_2_]]

"Tzortzakakis Dimitrios" wrote in message
...

Ï "stan" Ýãñáøå óôï ìÞíõìá
...
I was fortunate enough to pick-up a Pioneer SX-3700 on eBay recently
without any burned-out bulbs - which is pretty amazing considering the
unit was 28 years old and has no less than 11 bulbs inside! Imagine my
dismay when, after using DeoxIT to clean the noisy switches and pots, then
reassembled the unit only to find I had somehow broken two of the bulb
filaments while working on the receiver.

The required bulbs with leads can be purchased through eBay, but not
wanting to wait for the auction to end, in addition to the shipping
delay, I thought I would take a chance with a wired bulb that is readily
available from a nearby Radio Shack. The service manual calls for an 8V;
50 mA bulb, whereas the closest Radio Shack equivalent is 6V; 25 mA (cat
no. 272-1140). Since the bulbs were only $1.49 each, I wouldn't be out
too much money if they didn't work, either. I snipped-off the old bulbs
near the base of the bulb with wire cutters, then soldered the new wired
bulbs with a ¼-Watt; 100-Ohm resistor in series, to drop the higher
supply voltage to match the requirements of each replacement bulb.
You'll need to thread the leads of the new bulb through the plastic
holder before soldering, since the bulb is too "fat" to be slid up
through the back end of the plastic lamp holder. I wrapped the soldered
leads individually with electrical tape, including the entire resistor
and all conductive surfaces to avoid any potential arcing with other
nearby circuitry - ideally heat-shrinking insulation would probably be a
better choice if you have it available.

Also note that the bulb diameter is just a hair larger than the
factory-installed bulb - this shouldn't be a problem, though. The bulb
holder spreads-out from the back-end to the front-end, so the bulb will
seat a bit farther forward - but not so much that it would protrude
beyond the face of the holder. In my opinion this is an advantage, since
it increases the visible luminescence of the replacement bulb - while it
consumes half the current of the bulb it replaces, the brightness seems
comparable to its surrounding siblings.

So if you have a Pioneer SX-3500/3600/3700/3800/3900 with burned-out
bulbs, and you also have a soldering iron, with a bit of care and
patience you too can fix them today!

What do you mean by bulbs, vacuum tubes? If yes, you probably mean the
filament voltage? Are you sure you got the same tube? They have a type
number, eq like 807 or 6C4, the usual specs a working frequency, plate
voltage, negative bias for control grid and possible screen voltage.
Usually, they have also a pin layout. There used to be thousands of vacuum
tubes.


--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr


They're not tubes (valves). They are incandescent lead lamps.

Mark Z.