Speedotron 2401a

[Don Dudenbostel]

Remembered one other imPortant detail. Unless these have been modified, the trigger voltage is too high for 35mm cameras. The trigger voltage is 90v if I remember correctly and will fry the contacts in a 35mm or DSLR. You can get a device called a safe sync which is a tiny transformer that plugs into the strobe and limits the voltage. 90v is fine for copal, compur, prontor and ilex shutters but not others.

Remember these are old units. They were around in the early 80's if not earlier. If you question anything contact Speedotron in Chicago. They're great folks and reasonable and fast on repairs. You might feel better just getting it checked and brought up to date.

[MikeGuilbault]

You're dealing with a great deal of power, 2400 joules. It only takes 50 joules to stop your heart so be safe.

That's why I think I want to bring them in for a check out. I'm north of Toronto, Canada, so will have to find a service shop here. These suckers are way to heavy to ship to Chicago!

I hadn't heard about the switching power during recycle Don.. thanks for that head's up too.

[Don Dudenbostel]

It's a good idea to get them checked. There should be a shop in Toronto that can do it. As old as these are insulation deteriorates and corrosion is possible. With a checkup and any service needed they should go another thirty years.

Since digital came along I now use Force 10's. I have eight of them and still have a Norman 2000 and heads plus some smaller monolights. I had six 2000 normans, three 4000 and 3 800's at one time along with about 40,000 ws of Speedo and much prefer the speedotrons over anything I've used. This was in the days of 11x14 and 8x10 chromes for catalog work in the studio. Times have changed with digital. Actually just in time because I'm not getting any younger.

[MikeGuilbault]

They are rather heavy, aren't they! I've always used Photogenic lights and have most of the accessories for them, but if these work out well, they'll become my studio set up and I'll keep the Photogenics for location work where I often need to place the strobes further than the 20' of cord on the Speedo heads.

[JW Dewdney]

Capacitors don't generally pop, it's diodes that make a big bang. I had several diodes blow on Norman 2000 packs. It will get your attention.

Oh really! I didn't know that about the diodes - I'd always heard about caps popping so maybe the lore is wrong. I guess it makes sense, as a cap doesn't present much mechanical resistance... and a 'bomb' is only as strong as it's container as they say...

[polyglot]

Caps can pop but usually when they die they just split, smoke a bit and spray hot electrolyte about the casing. That can damage other electronics but it's generally only a whiffling sound and really bad smell.

Diodes often fail short and in a typical flash circuit, that means that the whole energy from the capacitor bank will be dumped into the diode. I think the usual culprits are the reverse-protection diodes that soak up the tail/overshoot of the discharge pulse from stray inductance in the head, and thereby protect the flash capacitors from any reversed polarity charge. The full voltage of the capacitor pack is expressed directly across them so when they let go, it's spectacular: dump a couple kJ into about 2mm^3 of silicon and it's going to part company with itself in very short order.

[SpeedGraphicMan]

Never use another manufacturers heads on your pack unless the have been adapted or you have the proper pigtails. The connectors may be the same but the voltages may be different. In almost all cases the pin configuration / wiring is different. For example Speedotrons and Norman used the same plug as did early 60's Ascor. The voltages were correct but the Norman plugs brought high voltage in on the pins that Speedotron connected the cooling fan through. You connect the wrong head and you have 900v on the fan. Pigtails can be made to use Norman heads on Speedo and speedo on Norman.

There are a few exceptions but generally this is the safe rule. You're dealing with a great deal of power, 2400 joules. It only takes 50 joules to stop your heart so be safe.

Please watch this, also different heads use different pin configurations so that the max WS is not exceeded thereby blowing the tube.

I might add that you are one lucky son of a gun!

[Don Dudenbostel]

I've had several diodes pop in Norman units. It's like a shotgun going off. When it happens you'll need to change your pants after you come down from the ceiling. Sometimes you get a nice ball of fire out of the pack too.

I was shooting with two 800ws Normans during a live surgery one day when the capacitor failed and started filling the surgical suite with smoke. Very bad! No bang but plenty of smelly smoke.

[Peter De Smidt]

Read the user guides. For instance, some people try to discharge the pack after they shut it off by quickly pressing the "fire" button. Speedotron specifically says not to do this, but as I said, I see it all the time. Also, if a pack hasn't been used in awhile, power it up, and let it sit for awhile to let the capacitors "form". Don't fire it. I'm not sure exactly how long to leave it charge before firing, but I gave mine an hour when I bought them. (They had sat for a few years.)

[JW Dewdney]

Read the user guides. For instance, some people try to discharge the pack after they shut it off by quickly pressing the "fire" button. Speedotron specifically says not to do this, but as I said, I see it all the time. Also, if a pack hasn't been used in awhile, power it up, and let it sit for awhile to let the capacitors "form". Don't fire it. I'm not sure exactly how long to leave it charge before firing, but I gave mine an hour when I bought them. (They had sat for a few years.)

good to know! i'm one of the guilty ones... I always fire off one after shutting off my 4802 or whatever it's called.