It happens that spamlet formulated :
"Harry Bloomfield" wrote in message
. uk...
wrote :
On 21 May, "spamlet" wrote:

Are there any good ones out there?

IME no. I've ended up changing to two port valves. They seem much more
reliable (10+years rather than 6 months)

Nothing at all wrong with the actual valve, just the actuator design which
lets it so badly down. It simply needs someone to design something more
robust, which has the motor move the valve to the correct position then
stop - rather than the motor constantly oscillating on the microswitches
against the spring. Surprisingly, I have not seen a DIY replacement
actuator yet, but it doesn't look at all difficult to do.

-- Regards,
Harry (M1BYT) (L)

There's a job for you Harry: sign me up for one when you've sussed it!
I would imagine that while they have us over a barrel knowing we have to buy
new every other year, there is not much incentive to come up with a different
design.

S

There is a rather good web site somewhere which explains their
principle of operation and how to repair them.

It needs something like a tiny DC motor (to provide forward and reverse
motion), geared down to provide the torque, a two lobe cam to trigger
the two micro-switches - then a timer circuit to run it back to the
default position.

Even an electrically operated brake, which held the position and turned
off the motor - would be a major improvement on the existing botch of a
continual rocking motion.

Food for thought.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk