Door Entry System Fault

[Daljit]

Hi there

I have just bought a flat that has a very old door entry system that isn't working properly. The following functions work fine: buzzer rings when visitor arrives; visitors can hear me speak; i can let people enter the building; and privacy switch works. However, visitors can't hear my voice.

I had a look at a neighbours entry phone which works perfectly and i found it had a small black box (about an inch square) with two wires in the casing. The box seemed to be added-on (perhaps as a result of a repair or modification) as is wasn't securly fastened. The two wires were hooked to the system.

Other than this box, the wiring in my phone is identical to my neighbour's.

I know this description is really vague, but does anyone have any suggestions what this little black box does, and more importantly, what it's called?

thanks

Daljit

[buffalobill]

from buffalo ny: so they can or cannot hear you at the door? what is the proper function of the privacy switch? if yours is a single separate home, not multiple apartments talking to the same entry, depending on what devices you are using, the power supply voltage, the condition of the outdoor speaker, the condition of a possible outdoor capacitor, the pushbutton above, the doorbell button, each device and section of the controls must be tested with a digital multimeter at the neighbor's home and compared to the identical measurements in your home. depending on whether you have a dedicated control unit above, what voltage available, how many wires available, and what appearance you desire, it may be possible to replace a handset above talking to speaker at the door with a two-wire battery operated push to talk intercom with master above and speaker/capacitor below. see there is a separate pair of wires for the buzz unlock; a separate pair of battery intercom wires; a separate transmitted or shielded video wire from front door camera to upstairs tv set.

[micr0]

a microphone?

[mm]

What does the privacy switch do? I would think the normal state of affairs is that people at the front door can't hear what is going on in your flat. Why do you need more privacy than that?

Talking to the same entrance???

What do you have in your box? I would expect to see a speaker (from the rear) and a microphone (from the rear). How many wires in the box go to devices on the front panel of the box? In addition to whatever wires go to the switch, four?? If so, two go your speaker and two go to your microphone.

How does thiis compare with your neighbor's? It may be that your mike has failed, and it may be that your n'bor's mike failed to, so it was replaced with the black box you see. How many wires does he have going to the face plate. Or better yet maybe, look at a 2nd neighbor's box. Are there board meetings where you could ask, or where you could learn of someone who knows these things already?

So you could need a mike, like his, or, otoh, never forget the possibility that a wire is broken. If the box was opened too many times, there might be a broken wire at the mike itself or in the box that goes to the mike. The break could be hidden by the insulation. If you have someone listen at the door and you wiggle the wires while talking into the mike, that might disclose a broken wire.

But a whole mike won't be expensive. I don't know what kind of stores they have in the UK, but I"m sure someoen sells it. If you can get one more like the one that it has already, maybe you can affix it to the front plate, but otoh, as you see, it works fine as your n'bor has it.

A mike or microphone.

[Mark Lloyd]

[snip]

If they're like some of the wired intercoms I've seen, they may work with only 2 wires. The speaker and microphone are even the same component. I've forgotten how they get the signal (call) on those wires too, but they did it.

[snip]