I own a Heathkit IP-17 which had identical rating to the HP-23 that you
have. For higher amounts of current, I cobbled together the combination
of a Variac, a salvaged TV set power transformer, bridge rectifier, and
filter capacitors to do the job.

Although unregulated, it performed its job well for many years.

Sorenson and other firms manufacture large, regulated power supplies
that will do arguably better work, but even used these generally
command a price of several hundred dollar, compared to the $30 or so
that I invested in my home built variable voltage supply.

Try periodically checking on eBay.

Good luck. Harry C.

) writes:
I own a Heathkit IP-17 which had identical rating to the HP-23 that you
have. For higher amounts of current, I cobbled together the combination
of a Variac, a salvaged TV set power transformer, bridge rectifier, and
filter capacitors to do the job.

Although unregulated, it performed its job well for many years.

There have been a few threads recently about regulated tube supplies,
and each time I see them, I keep wanting to post "but most supplies in
the days of tubes were not regulated".

It's almost as if people have lost that fact, so used to solid state
where regulation is the norm, though regulation there often means
a different thing. Now it's used to get a low impedance out of the power
supply, or because the devices are finicky over a wide range of voltages (or
outright can be damaged by too much voltage, as in the case of ttl). Of
course, three terminal regulators made it easy to add regulation to
just about any sold state design decades ago.

But of course, for most consumer equipment there were no regulators (though
that may mean little since there was little consumer electronics around
the house up till about forty years ago) If there was regulation it
was a VR tube, and for a specific stage or stages, liked an oscillator
stage that would change frequency with voltage variation, rather than making
the whole supply regulated.

It was in the lab that most regulated supplies were seen. All that
test equipment is a prime example. You wanted reproduceability for
that DC coupled scope, so you'd want it well regulated.

I guess in the lab you'd see variable voltage regulated supplies but
that would have been the key place.

Michael VE2BVW

Michael, excellent point all.

Years back I used Lambda regulated H.V. supplies in the workplace, but
only for critical application in experimental physics apparatus where
the accuracy and stability of the voltage had an important impact on
our research. (I still own a comercially produced 0-5 Kv regulated
supply, whose use is largely limited to powering photomultiplier tubes
used in nuclear research applications.)

Like you, I don't recall voltage regulation ever playing a significant
role in vacuum tube electronics, except for those instance that you
mention using VR tubes (as in my Hallicrafters SX-71 receiver to
stabilize the local oscillator). Still, stabilizing that sucker
required much more effort than simpy a VR tube!

Sadly, I gave away the original Variac adjustable power supply to a
student that had greater need for it than myslef. Then too, very little
of the vacuum tube work I do today requires more than a few mils which
My Heatkit IP-17 supplies.

Kindest regards, Harry C.

wrote in message
ups.com...
Michael, excellent point all.

Years back I used Lambda regulated H.V. supplies in the workplace, but
only for critical application in experimental physics apparatus where
the accuracy and stability of the voltage had an important impact on
our research. (I still own a comercially produced 0-5 Kv regulated
supply, whose use is largely limited to powering photomultiplier tubes
used in nuclear research applications.)

Like you, I don't recall voltage regulation ever playing a significant
role in vacuum tube electronics, except for those instance that you
mention using VR tubes (as in my Hallicrafters SX-71 receiver to
stabilize the local oscillator). Still, stabilizing that sucker
required much more effort than simpy a VR tube!

Sadly, I gave away the original Variac adjustable power supply to a
student that had greater need for it than myslef. Then too, very little
of the vacuum tube work I do today requires more than a few mils which
My Heatkit IP-17 supplies.

Kindest regards, Harry C.

What a small world, Harry. I was a field engineer for 25 years working
mostly on Gamma Cameras. I sold a business a few years ago that primarily
retrofitted Nuclear Medicine Gamma Cameras. I heard that there was a man in
the Chicago area who set up a photomultiplier tube to track the moon for
EME. I never found out his name, but probably could, if I made an effort.
Are you a physics professor?

Cordially,
west
AF4GC