old flash head, how to know watt-sec

[seekinglight]

How can I find out how many watt-sec my old Novatron flash heads can handle?

I have a Novatron 333 and three Novatron flash heads inherited from my father. Circa late 1960's early 1970's. There are no part numbers on the flash heads. Not watt-sec ratings. Not even a brand name. Because one flash head is not adjustable, another has a single hi/low switch, and the third has the -1 stop rocker switch, I believe these came as a kit with the 333 power pack. I've read the old 5-pin versions like this don't go over 500 watt-sec, but I think some are rated much lower than that. Surely there is some (non-destructive) way to tell the rating?

It all works, and I took team photos and player portrait shots two months ago -but I want to have more light and add a power pack -but don't know what these flash heads can handle.

(Please no "what you should buy" answers. I know what I can buy -I'm trying to learn what I have. thanks for help or referrals. )

 

[Dwig]

If memory serves (and sometimes it does) the old Novatron heads from the early '70s and earlier had a maximum rating of around 220w/s. A "heavier duty" tube became available in the late '70s that allowed 440w/s per head.

Keep in mine that the switched heads channel the unused power to the other heads and should NEVER be used as a single head in their lower power setting. If you connect two heads to the 333 pack with the switch head in hi you will feed approx 165w/s to each head. If you set the switch head to low -1 it will get approx 111w/s and the other head will get 222w/s.

If you use the switch head alone in the low position it will get 333w/s with approx half going to the resistor in the head and half to the flash tube. The result will be failure of the resistor in a short time. If you must have lower power in a single head setup the trick is to use two heads with one hidden in a drawer (be sure to provide ventilation and disable the modeling light).