First things: I measured the voltage between the center contact
and the shoe shell contact, and it's 9.5V on my R/S meter, which
reads a bit high. So probably 9V. Does that sound safe for a Canon
XT?
I assume the "DM/C" module means it fit FD, or whatever the Canon
film camera flash standard was in the early '80s. It has two
contacts in addition to the center contact. So I assume the XT
would treat it like a manual flash.
The flash has three manual zoom settings - W, N, and T. But there
are two other settings. One sets the ASA (25 to 800), and the
other selects between M(anual) and one of three colored dots -
orange, green and red. I believe the dots are related to the
thyristor function, but I don't know in what way.
Also there's a green LED that lights up for a second when I trigger
the flash in any of the dot settings, but not in M mode. I'm not
sure what the LED indicates.
Well, if anyone has any explanations, or a link to the manual, or
warnings, please post a response. Thanks very much.
A Google search on "Vivitar Zoom Thyristor 3500" yielded 12,800 hits
including some discussions that look likely to be of help.
As a general rule, it is worth searching on Google before you ask
people for advice on here, because it is quite possible that your
questions have already been answered.
>I was given one of these today, but can't find a manual anywhere.
Some Vivitar flash manuals here, but none for the 3500:
http://www.butkus.org/chinon/vivitar_flashes/vivitar_flash_units.htm
I am getting rid of items for a relative who has gone abroad. Amongst
them is
a Vivitar Zoom Thrystor 3500 flash with a small integral unit at the
base that pulls away. I doubt seeing that the manual was printed in June
1982, I doubt the unit has any value. Perhaps someone can confirm.
If that assumption is correct may be I can get the manual to you
physically or scanning the English pages to a pdf