briankelly63
Active Member
Since I used to be in the Telecom business I'm more sensistive than most users to phone line noise. When a device like the M1 takes control of your call there should be no low level hiss, buzz, hum etc... It should be DEAD quiet. This can be especially annoying when using the two-way listen in interface. I was experiancing a low level, low frequency buzz with a bit of microprocessor clock noise. Some people might not notice this...
After a bit of email coorespondence with Elk they sent back the following:
"The M1 has a built-in Switching power supply circuit. This is the supply for the circuitry on the M1 and also supplies power for the data bus devices. Apparently in his situation the “switching noise” is getting amplified when loads are present on the data bus. Depending on his current environmental conditions a replacement unit may produce the same results. One other possible solution would be take the +VKP and wrap it around a Ferrite Coil and retest. If the LC circuit or the separate power supply resolves the induced noise continue to use one of these devices. "
The ferrite coil suggestion does not work because the noise is too low a frequency.
The solution was to either power the keypads with a seperate power supply or you can build your own little combination inductor / capacitor filter circuit to feed the keypads. I decided to go with the sep. power supply which adds some redundancy to the system.
My phone line call in's to the M1 either local or remote are now perfectly DEAD quiet .
After a bit of email coorespondence with Elk they sent back the following:
"The M1 has a built-in Switching power supply circuit. This is the supply for the circuitry on the M1 and also supplies power for the data bus devices. Apparently in his situation the “switching noise” is getting amplified when loads are present on the data bus. Depending on his current environmental conditions a replacement unit may produce the same results. One other possible solution would be take the +VKP and wrap it around a Ferrite Coil and retest. If the LC circuit or the separate power supply resolves the induced noise continue to use one of these devices. "
The ferrite coil suggestion does not work because the noise is too low a frequency.
The solution was to either power the keypads with a seperate power supply or you can build your own little combination inductor / capacitor filter circuit to feed the keypads. I decided to go with the sep. power supply which adds some redundancy to the system.
My phone line call in's to the M1 either local or remote are now perfectly DEAD quiet .
