? ? One could put an oscilloscope across the output of a CVT to
test for both gross distortion and suppression of spikes and
noise on the power line. Modern CVTs do not produce much
distortion and low distortion ones can be ordered.
? ? The ultimate way to get clean power is to use a UPS. They
can provide complete isolation from the shore power line. The
amount of distortion depends on the design but low distortion UPS
sytems are available since some equipment doesn't like much
distortion. This is probably the most expensive way of
eliminating power line glitches but also provides very reliable
power.
? ? Lots of people do not like CVTs and there is a lot of myth
about them but IMO they work well and do shut down if there is a
short in the demand side. Some say they don't shut down fast
enough but if so I am not sure a fuse would be much faster. I
have had equipment saved by a CVT shutting down.
? ? They are indeed heavy, get quite hot, and can be mechanically
noisy although not all are.

On 8/22/2018 12:34 PM, Jeremy Nichols wrote:
> I don't have a whole-bench surge suppressor as we don't have
> severe power spikes or brownouts in this area. (Much of my
> equipment is non-solid-state and less sensitive to power line
> noise/spikes.) For the sensitive stuff, I have a Sola constant
> voltage transformer (CVT), which I occasionally use. CVTs are
> big, heavy, and emits an annoying hum in operation. They also use
> power even when operating without a load.
>
> I tested the CVT on a Variac and confirmed its ability to provide
> 115 VAC out regardless of input (in the range 100–130 VAC).
> Lacking the ability to put large spikes on my AC power line, I
> haven't tested the CVT's ability to knock them down. Without a
> load, my Sola uses about as much energy as a 60 Watt light bulb.
> Interestingly, this waste energy largely goes away as the CVT
> sees a load.
>
> CVTs contain only a transformer and some AC capacitors. Smaller
> ones like mine plug into an AC outlet; larger ones usually are
> hard-wired into the electrical system they serve. Mine, bought
> from an eBay seller (yes, risky, but <$100 including shipping)
> needed only a good cleaning before I put it into use. It's
> another option to consider for protecting sensitive equipment.
>
> Jeremy

--
Richard Knoppow
dickburk@...
WB6KBL