In the past when I've needed a lamp limiter it's always been a horrible bodge with a Safebloc, croc clips etc. So I built a fairly posh one using only bits from the junk box. It's not a thing of great beauty (the box lid is very secondhand but you can't see it) and the internal wiring is adequate rather than lovely but it works just fine and is safe.
It's got 40W, 60W and 100W lamps, obviously easily swapped for special requirements. Input and output are IEC 3 pin connectors because I hate captive mains leads. Labels are printed paper stuck on with PVA. I ought to out some varnish over them to keep them clean.
That looks an excellent piece of kit.
Before I made a proper one I used to use a small table lamp with the plug removed. The biggest drawback was if the equipment did not have a mains fuse that I could solder the wires to.
Al
Nice! Look good with some of those red bulbs that were used in electric fire glow effect fires! For labels I use one of the Brother thermal tape printers, they do a pretty good job make my equipment look almost professional.
I use my limiter with my 60w Weller mains iron as I feel it gives the element an easier life.
Alan
I cut a hole in the bottom of a tin can so that it fits on the bayonet lampholder and protects the bulb, GLS filament bulbs are an endangered specie.
I have an evil double socket on a short cord with a suitable WARNING.
The two sockets are wired in series by cutting a neutral brass strip on one and the live feed brass strip on the other.
The socket with a real neutral is for the equipment under test.
I like Sam's tin can idea, though it makes the filaments less visible. Part of the joy of a lamp limiter is that you get an instant visual indication of what's happening. I was thinking of mounting 4 pillars on the box that are slightly taller than the lamps. Would protect them from many things. Possibly some bits of M5 or M6 studding. Maybe even a little hat over the top too. It will probably never happen.
I've more 60W and 100W "real" lamps than I'll need in several lifetimes. Not many 40W. Vast majority of the lighting in the house is LED, a few CFLs in things that are rarely used and a few 4' and 5' fluorescents in lofts and garage. Apart from one of my inspection lamps (GLS) and a halogen spot by my pillar drill I don't think there's any tungsten lighting at all. I don't do much with AM radio so wouldn't notice any RFI.
For a moment I though Mike Watterson was making a "death cable" with a 13A plug on each end. I think I did something similar to Mike's rig many years ago when I used a 1kW heater as ballast for some kind of discharge lamp. I fitted a 13A and a 5A socket in series on a bit of wood.
Ah, but my limiter is on the wall with the bulb horizontal, I can see the bowl end. I have a switch to short it out for full power. As I do only radios I use a 40w bulb.
I also have a universal fits anything socket on the limiter, 5A 3 and 2 pin, US, Asian, 2 USBs, & 13A of course. Handy for old stuff with the original plug still fitted.
No, I don't have bayonet or Mr. George Scholes' wonderful socket!
(19-05-2020, 12:25 PM)ppppenguin Wrote: [ -> ]For a moment I though Mike Watterson was making a "death cable" with a 13A plug on each end. I think I did something similar to Mike's rig many years ago when I used a 1kW heater as ballast for some kind of discharge lamp.
Where would the lamp and the radio plug in? It's a rubberised trailing socket, but with a very short mains lead. So one plug and two sockets. It's still a bit evil.
I don't do old TVs, not since about 1972. I've not even seen one in real life since then. So I've only resorted to the "limiter" once. It was for the HMV 1507.
https://www.radiomuseum.org/r/hismasters_1507.html There is a veneer version. One of the few radios I've bought at an Irish auction. There was a big collection. Some stranger saw me puzzling over the HMV 1507.
"It's a radiogram! Open the back!"
It was still erratic but not blowing fuses when I put it in the vintage radio store part of the attic. I meant to use two cheap ceramic cartridges, one with 78 and other with microgroove by cutting off the tabs and casing in thin black plastic. It uses a huge isolation transformer for the pickup as the chassis is live, but the deck / arm is sort of earthed. Strange 3 pole mains plug on the side. The last photo shows the audio in transformer.
Someone sent photos of the dual cartridge (often missing and usually dead). About 1/2 down scroll list. Seems a mad idea compared to a flip over needle. Perhaps different compliance and sensitivity. A flip-over needle may be a compromise solution? Some early 1950s models used two interchangeable heads, one "docked" on the other rear corner (one Pye and one Pilot I know).