Sansui R-303 Stereo Receiver

[lcdman]

Hello All,

I'm almost finished restoring a Sansui R-303 Receiver. But I'm not having any luck sourcing a replacement bulb for the back-lit tuning dial. The old bulb had a blue sheath around it to change the light color to blue. I tried measuring the connection point for the old bulb to get the voltage info. I got 18.50VAC.
Does anyone know where to locate such a bulb? Or perhaps a circuit to drive a regular blue LED in its place? Any help at all would be greatly appreciated!

Have A Great Holiday Weekend
lcdman

[kc8adu]

Re: Sansui R-303 Stereo Receiver

nothing there for scale but it looks like a common grain of wheat like the ham rigs use.
are there several in series?i suspect that is a 24v or a more common 12v and a series resistor.
and i often replace with led's.unless its a marantz blue may look tacky.
the tinted boot whitens it.
maybe white led's?
you will need a diode too.
or run em from another regulated source.

[lcdman]

Re: Sansui R-303 Stereo Receiver

Hello kc8adu,

Thanks for the reply. There is just one bulb lighting the entire dial. So I should be looking for a 24v bulb instead? You mentioned a diode or resistor. There is one resistor on the circuit board that the blown bulb came off of. What about a circuit diagram to replace the bulb all together? I haven't had any luck sourcing a free schematic for this receiver either.

Thanks Again
lcdman

[selldoor]

Re: Sansui R-303 Stereo Receiver

How about one of these - Doesnt seem to say if its ac or dc

http://www.bulbtown.com/2102_MINIATU...ASE_p/2102.htm

[lcdman]

Re: Sansui R-303 Stereo Receiver

Hello selldoor,

I seen that site as well. And it doesn't say AC or DC? It looks like what I have now that don't light up. I did look into those grains of rice bulbs that were mentioned in a earlier post. Those might work as well. No one has replied about a schematic for this receiver as of yet either.

Thanks
lcdman

[kc8adu]

Re: Sansui R-303 Stereo Receiver

incandecents dont care about ac or dc.
just had a yaesu g800 rotor control in here with a dead bulb.it ran from the 14v ac winding on the transformer.a 1n4007,white led,and a 470 ohm resistor and it should be good forever.
if the slight flicker bugs you a small lytic across the led will reduce that.
since it edge lights the scale i used a diffused led.
your sansui probably does too.

[lcdman]

Re: Sansui R-303 Stereo Receiver

Hello Again kc8adu,

Thank you again for your quick reply. I would rather use an LED than a regular miniature bulb. Would you be so kind to put all those parts you mentioned in your last post into a labeled schematic? I'd like to return this receiver to its owner soon. I'd be very grateful if you would!

Thanks As Always
lcdman

[Bobhoskin]

Re: Sansui R-303 Stereo Receiver

Hi LCDman, I've the same Sansui R303, with the same bulb problem, do you found a solution?

Other than this, I've a bigger problem, audio it's all distorted and can't regulate Volume.....
here: https://www.badcaps.net/forum/showth...542#post339542

[Guyinagt]

Re: Sansui R-303 Stereo Receiver

Hello All,

I'm almost finished restoring a Sansui R-303 Receiver. But I'm not having any luck sourcing a replacement bulb for the back-lit tuning dial. The old bulb had a blue sheath around it to change the light color to blue. I tried measuring the connection point for the old bulb to get the voltage info. I got 18.50VAC.
Does anyone know where to locate such a bulb? Or perhaps a circuit to drive a regular blue LED in its place? Any help at all would be greatly appreciated!

Have A Great Holiday Weekend
lcdman

Hi, I know this is an old thread but I've only just found it while researching the same problem with an R-410 receiver (Same circuit as R-303).
Did you ever find a sensible answer to your quest?
The original lamp is 12 Volts at 150mA.
I haven't been able to find an exact replacement but I have found one of 12 Volts at 100mA which will do the job, albeit a little less brightly. 4mm diameter x 10mm long.
The 39 Ohm series resistor on the PSU board needs to be changed to 60 (62) Ohms, 1 Watt to suit. (or add a 20 (22) Ohm, 0.5 Watt resistor into one of the leads to the lamp board).
An LED won't do the job, even though it is straightforward to cobble one in with a suitable diode and resistor, because the light needs to radiate all around the lamp to properly illuminate the plastic dial, whereas an LED radiates from the end only and doesn't illuminate the plastic 'ears'.

[digix]

Re: Sansui R-303 Stereo Receiver

Hi, I know this is an old thread but I've only just found it while researching the same problem with an R-410 receiver (Same circuit as R-303).
Did you ever find a sensible answer to your quest?
The original lamp is 12 Volts at 150mA.
I haven't been able to find an exact replacement but I have found one of 12 Volts at 100mA which will do the job, albeit a little less brightly. 4mm diameter x 10mm long.
The 39 Ohm series resistor on the PSU board needs to be changed to 60 (62) Ohms, 1 Watt to suit. (or add a 20 (22) Ohm, 0.5 Watt resistor into one of the leads to the lamp board).
An LED won't do the job, even though it is straightforward to cobble one in with a suitable diode and resistor, because the light needs to radiate all around the lamp to properly illuminate the plastic dial, whereas an LED radiates from the end only and doesn't illuminate the plastic 'ears'.

Hi! Have you find the scale bulb for Sansui R-410 ? If yes, please give me a link.