128 lines
3.3 KiB
Plaintext
128 lines
3.3 KiB
Plaintext
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X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X
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-= PHONE GADGETS =-
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Conference Caller
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Hold Button
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by
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-- anonymous wizard --
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X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X
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>>> Standard Disclaimer <<<
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Anything you connect to the phone lines
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is *supposed* to be FCC registered, to
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make sure it won't injure repairmen or
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damage equipment. The gadgets des-
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cribed in this file do NOT apply any
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extra voltage to the line, and should
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be safe. If in doubt, check with the
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phone company before connecting any
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stuff to your line. (These gadgets do
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not put any extra "ringer equivalence"
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on your line, either.)
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X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X
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CONFERENCE CALLER
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If you have two phone lines, you can
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this simple attachment to set up your
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own conference calls. You'll never pay
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to have an operator set them up for you
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again. Once you've called the two
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other people on your two lines, you
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just throw the switch. All three of
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you can now talk to each other.
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Phone lines carry voices as audio
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frequencies superimposed on DC control
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voltages (around 40-50 volts when not
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in use, with higher pulses when
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ringing; around 10 volts when a phone
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is being used -- I forget the exact
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numbers, but those are close.)
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The two lines can be connected through
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capacitors, so the audio passes between
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the two, but the DC voltages don't
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interfere with each other. (If you
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simply short the lines together, the
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phone company may not like it!)
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Use this simple circuit:
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! !
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red --------! !---o: o------ red
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! ! :
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(line 1) : (line 2)
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! !
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green--------! !---o o------green
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! !
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^ ^
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capacitors DPST
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.1 to 1 uf switch
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(not critical)
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(do *not* use polarized electrolytics!)
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(This circuit is similar to the other
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conference caller mentioned on the
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Roman Forum, which doesn't have the
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capacitors.)
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X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X<>X
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HOLD BUTTON
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This gadget also is a variation on one
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posted on the Roman Forum.
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Shorting the line is not a good idea.
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A resistance of 1-2K is enough to hold
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the line, without making the line look
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screwed up to the phone company.
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red ------o o----\\\\------ green
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SPST 1-2K
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switch
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(It doesn't matter which direction you
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connect this circuit in -- red-to-green
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and green-to-red both work.)
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If you like, you can add an LED that
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will light whenever you have someone on
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hold. Just connect the LED in series
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with the switch and resistor (now about
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500 ohms to 1.5k, depending on your LED
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-- experiment!). Like this:
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^^
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!\ !
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red -----o o----\\\\-----! >!--- green
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! !
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SPST sw. .5-1.5K LED
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This circuit (with the LED) only works
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if it's connected in the right direc-
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tion. Phone wiring isn't always done
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right; before you wire this one in
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permanently, try switching the red and
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green wires, and leave it in the
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direction that works.
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ENJOY!
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X<>X<>X< anonymous wizard >X<>X<>X
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