Putting the finishing touches to a 1930's floor stander radio which I have mentioned in another thread. Has the 57/58/55 2.5v valve lineup and the original dial bulb runs of the heater supply.

The original bulb has long blown and been putting in 2.5v torch bulbs but they do not last long as guess torch bulbs not meant for continuous duty.

By chance would the be a supplier whom has 2.5v edison screw bulbs about, perhaps a stash of NOS bulbs ?

Incandescent bulbs are getting hard to find nowadays. LED's give a horrible blueish light and I avoid the LED path.

Thanks for any help with this.

The automotive supplies would probably have old stock of the miniature interior light fittings.
So, perhaps we may have to resort to say an old plugpack transformer hidden within the chassis and a separate dial light circuit.
With the right voltage choices they could potentially (globes) last for a very long time.
JJ

I think I have some. I will check later. I have one in my 1934 STC model 55 I think and it is lasting well.

My oldest radio uses those bulbs, but they kept blowing so I switched over to 3.5 volt bulb, works great.

Last time I looked (a few years ago), both were available at Jaycar.

Yes 3.5's were suggested by a fellow collector and have a few but want to hang onto them for old torches I have.

Trouble is the day of the incandescent bulb is over and not sure Jaycar is now even selling torch bulbs of any sort.

Will have a look online.

Thanks

EDIT: just looked at Jaycar, they have a 4.8v krypton bulb which may do. A new store has opened up at Orange so will pay a visit.

As before there are very few incandescent bulbs about nowadays.

Thanks for the tip re Wagner, forgot about them.

Check also Wagner. They keep a pretty diverse stock of parts: https://www.wagneronline.com.au/

We still sell 2.5V MES bulbs at Jaycar, but I can't see where we ever sold a 3.5V type. Either that pre-dates the current record keeping system, or it might have been Dick Smith you're thinking of.

Actually we shift over 7,000 SL3210 a year, (actually 14,000 bulbs as they come in a pack of 2) as they're still widely used in kids' school projects.

https://www.jaycar.com.au/2-5v-screw-in-type-globe/p/SL3210

Also about as many of the "breadboard"sockets:

https://www.jaycar.com.au/bakelite-mes-globe-holder/p/SL2659

As for service life, basically, "they are what they are."
Some popular items are getting almost impossible to obtain now, and we have to take what we can get.
I suppose for a kids' school projects a short operating life isn't a big issue. For radio use I can only suggest you do a "burn-in" before actually fitting to the radio.

Incidentally, we also sell huge numbers of SL2654 annually, the 6.3V type.

Note that there are two types of 6.3V types. The long envelope one at around 300mA and a smaller round envelope & around half the current draw. These are the ones that don't burn holes in the dial plastic of "Empire States" & a few others.

Simplex I believe I might have some 2.5s here in my stack. If you see this send me a email reminder and I will look for them and you can have them. I have a box full.

You could insert in series a resistor or diode to cut the effective voltage on the bulbs. Which should make them last much longer.

I'd be careful going too high with the voltage rating. The higher the working voltage of a globe, the lower the resistance may be and you could get to the stage of creating a short in the circuit. WA2ISE's suggestion of a diode in series with the globe may do the trick. A 1N4001 in series will give a voltage drop of 0.6V and cost next to nothing and Jaycar will have boxes of them. If a slightly less intense glow from the globe isn't an issue, this should see it last a lot longer.

The only LED globes that are suitable for vintage radios are warm white but retailers absurdly believe that everyone wants the harsher daylight colour temperature and this is not the case. 3000K is perfect for radios.

Do some reading on any LED globes you buy. They may be expecting DC and most radio globe holders supply AC to the globe. In such cases, the best you'll get is a globe that flickers at the mains frequency. At worst, the driver may want to go on strike.