> ...When you switch on the
> SR620 the fan should be slowly increasing its speed over several
> minutes if the circuit is operating properly.
That's what my fan does (over abot 15min), but it doesn't stop
increasing until it's reached maximum speed.
> If you bought your SR620 second hand
of course...
> If the fan noise is very disturbing
indeed, it is
> you may consider replacing the fan
> with a low noise fan made for computer use.
That was my suggestion. Since there are a lot of fine fans from quality
manufacturers that shouldn'd be an issue. EBM Pabst for example sells 15
different 24V-types of that dimensions. But prior to this I will check
the electronics, of course.
mni tnx es 73 de df9pl
Volker
Am 13.11.2012 10:34, schrieb Jarl Risum:
Hello Volker
Thanks for your kind answer.
The fan in my SR620 is fairly quiet. As you are probably aware the fan
speed in the SR620 is controlled by a temperature sensor monitoring
the temperature of the exhaust air. One possible explanation for your
noisy fan could be that the sensor or (part of) the circuit
controlling the fan speed has become faulty. When you switch on the
SR620 the fan should be slowly increasing its speed over several
minutes if the circuit is operating properly.
If you bought your SR620 second hand the previous owner might have
tampered with the control circuit or the fan has been changed to
another type. My SR620 is equipped with the original fan as described
in the parts list: a Delta DBF0624H (24V / 0,11A). When I searched the
Internet for information about this fan I learned that is is no longer
manufactured.
If the fan noise is very disturbing you may consider replacing the fan
with a low noise fan made for computer use. Due to the moderate
temperatures in northern Europe this should be a fairly safe operation
even if the airflow maximum is slightly reduced. The Delta fan is a
standard 60x60x25 mm type so low noise alternatives should be easy to
find.
Good luck and best 73's from OZ9MO / Jarl
2012/11/12 Volker Esper<[email protected]>:
Thanks a lot, dear Jarl, those seem to be important hints!
Speaking of the cooling system: the fan of my SR reminds me of my experience
as an electician, when I had to work with 50kW-fans... I'm going to replace
that beast- is it typical for the SR to blow like a hair dryer? I can't
beleave that...
Cheers - Volker - DF9PL
Am 12.11.2012 21:14, schrieb Jarl Risum:
Hello Volker
You asked for Windows software to use with the SR620 counter and its
RS232 interface.
I have used John Miles' "TimeLab" with my SR620 and RS232 with great
success.
You may download TimeLab here: http://www.miles.io/timelab/readme.htm
It is freeware and supports a number of different counters, including
tha SR620. You just need to select the SR620 in the setup menu.
I would like to draw your attention to something perhaps obvious to
you: Please note that the SR620 need to be in operation for some time
- half an hour at least - before any attempt to calibrate it is
carried out. And it need to be placed with some space around it in
order to not get too hot after some hours of operation.
I would also like to add, that in my experience a Power Conditioner (
a medical qualified 230V to 230V transformer with a ground connected
static shield) to feed the SR620 with power is helpful to keep away
mains borne transients. Also an external circuit to convert sine
shaped input signals to square waves before feeding the SR620 input is
useful, as previously discussed on the Time Nuts reflector.
I wish you good luck with your experiments.
Cheers from OZ9MO /Jarl
(Danish Time-Nut)
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