[time-nuts] Anyone (ideally in the UK) got a spare rotary knob for the 5370B TI counter?

Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby at kirkbymicrowave.co.uk
Sat Dec 31 05:25:46 EST 2016

On 31 Dec 2016 02:03, "Bob Stewart" <bob at evoria.net> wrote:
> If you can touch the heat sink for 2 seconds, you're made of sterner
stuff than I am!  They run very hot.  It's a good idea to get a GPIB
extender so your GPIB cable can clear the heat sink.  Somebody, can't
remember who, worked up a nice looking conversion to a pair of switching

SMPSs tend to be less clean than a linear supply. I would be somewhat
reluctant to take that route on test equipment. But I will search for the

I have a 13 A variac sitting around that's not been used in the last 25
years. I think as a short term measure I will drop the voltage to a few
bits of the equipment with linear power supplies. The spectrum analyzer has
linear supplies and puts out a lot of heat.  As someone else said,  a 20 V
transformer would work. Adding the variac will take me 5 minutes to do,
which has an advantage over anything I need to build.

I will also log the mains voltage over a period of a few weeks and see if
it high enough to ask the electricity supply company to do something about
it.  I do know someone that measured his voltage and found it was outside
the legal limits. He advised the electricity supplier,  they agreed,  but
said that they were not going to do anything about it.  He wired his whole
house on an auto transformer.  I would be speaking to my Membrr of
Parliament (MP) if it was outside the legal limits. I don't know what legal
limits exist in the UK for voltage,  but I can find out.

It is unusual in the UK for a domestic property to have a phase supply, but
mine does.  I don't know whether any one phase is consistently lower than
any other. If so phases could be switched.  But given my close promptly to
the 11 kV transformer,  I doubt it.

I know at one point I had a dispute with the electricity supply company as
the 415 V overhead power lines used to be regularly hit by farm vehicles
down a private road where my property is. This would pull the cables away
from my house and make a mess of the house. The electricity supplier would
always repair the damage,  but after this happened a few times I
complained. I was initially told they would do nothing as it is not a road.
But I discovered that the cables needed to be a minimum height if there was
vehicular access. So whether the electricity supplier considered it a road
or not was irrelevant.  Eventually they extended a pole and raised the
cables up, which appears to have solved the problem.  Whether I can
convince them to move the transformer taps is another matter.  I suspect
that it might be hard if my supply is consistently high, but not outside
the legal limits.


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