Pip top bulbs and adulterations etc?

[chipp1968]

That made me laugh, now that's an idea .

[Techman]

Just found mine in a box up in the loft.

[Heatercathodeshort]

Royal Ediswan. That is a very early carbon lamp. The word 'Royal' was used on many products at that time that had no official connection or endorsement with the Royal Household. It upset Queen Victoria and things came to a head when the word Royal was connected to a toilet cleaner. The whole system was cleaned up some years later. A very nice example. Maybe feed it a little voltage and see how it looks. J.

[Techman]

Thanks for that really interesting info, John.

I've had that particular bulb for many years ampersand I knew it was old, but perhaps hadn't realised it was quite THAT old. I had not powered that bulb up for probably at least 25 years and I have to admit that I used to just pop it in a fitting ampersand switch on at full mains

I wound it up on a variac tonight but didn't go much above 200 volts. Something that I hadn't noticed until now was tha fact that the base although having 2 pegs, has another 2 holes for another 2 pegs, making 4 pegs, or was it so that there was an alternative position for the 2 pegs already there? I've shown a close up of the base.........



The glass is a bit grubby, but I'm going to leave it for now - don't want to damage that writing!

I've got some other 'unusual' bulbs ampersand I'll post them a bit further along.

Edit: Just to say that I think that these bulbs were made to 'hang' from a fitting rather than be mounted facing upwards as I've done - the way the carbon filament is supported it probably needs to 'hang' for maximum life....do you think?

[Ekco-Scott]

Yes on the boxes of my antique bulbs it says: lamps give best results when hung verticaly cap up. Certain of smaller sizes may be operated in any position but the vertical position should be adhered to if possible.

You have a lovely light bulb there and John that is an amazing collection you have

[Heatercathodeshort]

Most of my early bulbs have the four holes for the spigots. I have wondered why also. My guess is that early 110v lamps may have used the alternative holes thus not making contact when plugged into a 200/240v supply? I have a number of Edwardian lampholders that can be set up to take the alternative position.
Most early lamps were of course hung vertically but period catalogues show a number of elaborate table lamps with vertical lampholders. Most however show the lamp at an angle rather like a portable gas desk lamp. That is a super lamp but I can't help thinking how strange it is that some of these lamps are over 100 years old. Just think what has happened in the World since these lamps were manufactured by young ladies with nimble fingers. Regards, John.

[Ekco-Scott]

I have a bulb that has three spigots why would this be? I could never figer it out.

[Heatercathodeshort]

Some special bulbs were supplied with 3 pins so that they could not be plugged into a normal light socket as they were not designed to be connected directly to the mains supply. Bulbs used as Flourescent lamp ballasts in Atlas and Philips come to mind and the fireglow flame coloured bulbs used by Berry's Magicoal in their flame effect fires. In the case of Berry's this was more a marketing exercise rstricting you to using their own brand of replacement lamp. The fireglow lamp had no special qualities to require the 3 pin cap.
Pictures show a Philips ballast bulb and a 'fireglow' from Berry's. Cheers, John.

[Heatercathodeshort]

Just to complete the odd lamp caps used in Berrry's 'Magicoal' fires I have taken a shot of the pre war two pin lamp used in these models. It is a standard 60W lacquered type the originals being stained glass. This example is used in this 1936 fire in my dining room. The Mazda box appears to date from the 1960's. They were of course produced in the standard BC cap widely used by Messrs Belling and others. J.

[Ekco-Scott]

My bulb is made by Pansy lamps and is like the squirrel cage lamp the date code on the box is for 1912 so i'm guessing it is to stop the use of other brands of bulb in certain lamps.

Scott.

[John_BS]

This is a fascinating thread.

I only have one old bulb: 200v 40w. I noticed some time ago that this bulb seems to radiate RF energy at VHF frequencies: it appears to start at around 80% of rated voltage, and the spectra changes with changing voltage. Can anyone else confirm something similar for their lamp(s)?

John

[Heatercathodeshort]

What a super bulb John. It must be oscillating, an original source of R.F. interference.
A 1909 version of a low consumption bulb! John.

[Heatercathodeshort]

Just a thought John, how did you pick up the trace? Did you place an induction loop around the lamp or pick it up from the supply flex to the lamp? J.

[cmjones01]

Originally Posted by John_BS

I only have one old bulb: 200v 40w. I noticed some time ago that this bulb seems to radiate RF energy at VHF frequencies: it appears to start at around 80% of rated voltage, and the spectra changes with changing voltage. Can anyone else confirm something similar for their lamp(s)?

You've just confirmed for me a story which I thought might be apocryphal. Apparently filament bulbs can radiate at RF - something to do with plasma forming round the hot filament, I was told.

The story goes like this: the manufacturers of a shoe cleaning kit for the US military were forced to have it tested for EMC before they could supply it. They thought testing it was a waste of time, naturally. How can a shoe cleaning kit possibly fail an EMC test? Well, fail it did. The reason? It included a simple filament lamp, which was radiating RF. You have just posted the proof that it's possible - thank you!

Chris

[boxdoctor]

Lovely collection John. I particulrly like the Austrian "Only a Rose" one. My aunt had a similar one when I was a small child. Never forgot it - fascinating. Thanks for taking the trouble to show us those. Tony.

[Heatercathodeshort]

You are very welcome Tony. Only fair to share these fascinating early lamps with guys that appreciate them. Cheers, John.

[John_BS]

Originally Posted by Heatercathodeshort

Just a thought John, how did you pick up the trace? Did you place an induction loop around the lamp or pick it up from the supply flex to the lamp? J.

Nothing fancy: I just poked a short length of wire in the analyser input, and kept the bulb close-ish (200mm?). So we're observing E-field.

There's something a bit odd, as I recall when I originally "observed" this, it was on an HP 141 spectrum analyser (i.e real-time analogue scan). I thought I remembered the radiation looked like a big hump in the noise-floor somewhere in the VHF band.

The trace posted was taken an a more modern analyser, with digital processing. I had to invoke line triggering to get a consistent trace..... so the real-time waveform must be "locked" in some way to 50 or 100Hz.

John

[teetoon]

Hi, did anyone see "If walls could talk" BBC 4 tonight at 9:00 ? There was a man called Ray Tye with a large collection of vintage bulbs as discussed here. Bound to be repeated.

David.

[robin0577]

Originally Posted by teetoon

Hi, did anyone see "If walls could talk" BBC 4 tonight at 9:00 ? There was a man called Ray Tye with a large collection of vintage bulbs as discussed here. Bound to be repeated.

David.

Also available on iplayer http://www.bbc.co.uk/iplayer/episode...e_Living_Room/

[Ekco-Scott]

This is an intresting bulb. It has two filaments when one blows you simply tern the bulb round in the socket It Is a 110v 16w bulb I use a uk to usa step down transformer to use 110v bulbs.

Sorry web cam pics

The step down transformer is from maplin for £15 at the minute It gos up to 100w

Scott