Dave
The SP 310X has a pair of 6F6 triode connected driving a pushpull
transformer with output of 15 watts. It was mainly a military Rx BC 794
etc butmine is a civilian model.
No cathode follower.
Any headphones work fine at 10 ohms.

--
Thanks & 73
Hank WD5JFR
"Dave Plowman (News)" wrote in message
...
In article ,
Henry Kolesnik wrote:
Neil Sutcliffe was kind enough to send me a manual on his GR 783A
which
is a more recent version of my GR 583A Output Impedance Meter. The
o/p
xfrmr on my Hmmarlund Super Pro 210X Type O is 10 ohms and I looked
inside and saw no evidence that it was changed. I confirmed that the
meter works by the same technique on my Ten Tec SP 325 which is 600
ohms
and it measured 600 ohms. The GR 583A is a neat piece of gear, easy
as
pie to use.

If the output really is 600 ohms it sounds like it uses a cathode
follower
and was never designed to feed a speaker. 600 ohms is the old line
driving
impedance and headphones are available that will work fine from this
at
line level.

--
*Why do we say something is out of whack? What is a whack?

Dave Plowman London SW
To e-mail, change noise into sound.