Maker Pro
Maker Pro

Cheap Frequency Counter

P

Phil Allison

Jan 1, 1970
0
"John S"
Read more complete specs:

www.pira.cz/pdf/vc3165.pdf

I have one and I feel that the input and trigger sensitivity is low.


** The specs look OK to me - too much sensitivity leads to unstable
readings.

The mediocre frequency accuracy of such counters results from a crystal that
sits open on the PCB and so drifts with the local ambient temperature.

If there is a trimmer cap next to it, one can set the accuracy to better
than 1ppm using a broadcast frequency standard - assuming you are near
one - or using a known frequency reference. But the drift issue remains.

The biggest part of the temperature drift is mostly due to internal heat
sources in the unit, workshop room temps being comparatively stable. So all
you have to do is mount a small (ie 30mm) fan above the crystal, blowing
room temp air onto it.

Hey presto, no warm up drift.


..... Phil
 
Also bear in mind local import duty - in the UK; royal mail levies a
"handling charge" for collecting the revenue, that amounts to racketeering!

A few years ago I ordered a Jaycar kit for an EPE project (reproduced by
permission of Silicon Chip) - the RM "handling charge" was actually more
than the duty they collected!!!

yep same here, one cent over ~10 euro and they charge you 20euro
handling

-Lasse
 
J

Jamie

Jan 1, 1970
0
Ian said:
Also bear in mind local import duty - in the UK; royal mail levies a
"handling charge" for collecting the revenue, that amounts to racketeering!

A few years ago I ordered a Jaycar kit for an EPE project (reproduced by
permission of Silicon Chip) - the RM "handling charge" was actually more
than the duty they collected!!!

How's it feel?

Jamie
 
P

Phil Allison

Jan 1, 1970
0
"Paul Colby"
I got one of these. I haven't used it much but it does work. It's not very
fast takes a long time to "warm up" and
I have a real hard time reading the LED display. Not much difference
between a lit segment and an unlit one in
normal room light. I find this feature really bothersome.


** I can see a problem even in the pics on the page.

IME red LED displays have really excellent legibility - even in a well lit
workshop.

Funny how they seem to be out of fashion.



..... Phil
 
M

M. Hamed

Jan 1, 1970
0
Thanks All. The unit is on the way. I am having a hard time understanding the specs, aside from the obvious things, but it's Ok for now.
 
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