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N_Cook N_Cook is offline
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Default Code entry door-lock problem

On 17/07/2019 14:23, wrote:
The cost of those return visits has well-exceeded the cost of replacing the lock outright. Unless there is some level of local interference (not common, but I have seen this a time-or-four), that lock should have been replaced and should be operating flawlessly.

Now, on a couple of occasions, a local machine in operation stepped all over the locks nearby. One being an open MRI machine, the other being a defective hyfrecator. Both cases were solved with by installing shielded locks (and the hyfrecator was also replaced, of course). Do you have any unusual equipment within about 20' of that lock, especially something that is intermittent in use?

Peter Wieck
Melrose Park, PA


Interesting , I could see electronics connected to metalwork set in a
wooden door, being susceptible to electronic smog, but only the decoding
side of things or all , not just the power side of the delatching.
But over much the same time as this problem, they installed a unit that
uses the LoRaWAN structure , 850MHZ. It has enough power for city-wide
data capture but limited to a short data-squirt ,probably less than
10KB, every 15 minutes, unlikely to affect this codelock over 30/40
attempts I'd have thought, but it would explain the intermittency. Also
the RF from its external antenna and external generation, has to pass
through an external wall and 1 or 2 internal walls to get to this door.
Whether there is insufficient/lack of choking on the DC supply wiring to
this unit and large amount of RF being propogated over the mains wiring
of the building 4 times an hour , unknown.

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