IF4-4 Four-Wire Interface

Operation Manual

CLEAR-COM 810061

July 1983

I. INTRODUCTION TO THE IF4-4

The IF4-4 Four-Wire Interface ena­ female, XLR connectors (D3F) for bles up to four 4-wire communica­ interfacing up to four different tion systems (such as TV cameras) Clear-Com lines. to interface with the Clear-Com Intercom System. It also allows 3- The IF4-4 rear panel provides four wire systems to interface with 4-pin, male XLR connectors (D4M) Clear~om. The IF4-4 was designed for interfacing up to four 3-wire to match standard 600 ohm transmit/ or 4-wire systems to the Clear-Com receive lines (at normal levels) to lines. You can connect the 3-wire/ Clear-Com line level. 4-wire systems to separate intercom

channels, or you can put two, The IF4-4 is powered by the Clear­ three, or all four on one "party­Com System, which connects to the Line." IF4-4 with standard two-conductor shielded mic cable. The cable is The IF4-4 front panel contains run from the output connector of a transmit, receive, and sidetone Clear-Com Main or Remote Station to level controls for each interfaced the IF4-4. One wire carries 30 system. VDC, the other wire carries the intercom signal. and the shield The IF4-4 mounts in a standard 19" acts as common ground. The IF4-4 equipment rack; its front panel is rear panel provides four 3-pin, 1-3/4" high.

IMPORTANT: Please read ALL the follOWing instructions before connecting and operating the system.

II. SYSTEM CONNECTIONS

The IF4-4 provides four D4M connectors (designated J1 on the PCB Schematic, page 6) to interface with: --600 obm, balanced, four-wire (two send, two receive) systems or --600 ohm, unbalanced, tbree-wire (one send, one receive, one common) systems

1) Route two-conductor shielded 2) Connect the three- or four-wire cable from a Clear-Com Main or output lines from the system(s) Remote Station output connector to be interfaced (for instance, to the IF4-4 rear panel, and the output of a camera control input it to the D3F connector(s) unit) to the D4M connectors on (designated J2 on the PCB sche­ the IF4-4 rear panel. matic) •

On the D4M connectors, Pins 1 The pin assignments in Clear-Com and 2 are the input (receive), 3-pin intercom connectors are' 600 ohm bridging, -30 dBm mini­

Pin 1 - common mum/10k ohm. Pins 3 and 4 are Pin 2 - +30 volts DC the output (transmit), +1SdBm Pin 3 - intercom audio maximum level/600 ohm.

(continued)'

1

FIG. I IF4-4 INTERFACE CONFIGU RAT IONS

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DIAGRAMS ABOVE SHOW REAR PANEL OF IF4-4; Please note toggle switch settings

2

II. IF4-4 SYSTEM CONNECTIONS, continued

2) (continued from page 1) Note: The conductor pairs in a 4-wire balanced input are inter­changeable; in o t her words, it doesn't matter wh ich conductor in the first pair connects to Pin 1 or 2 (in the D4M), or which conductor in the other pair goes to Pi n 3 or 4.

3) If you wish to use the IF4-4 for interfacing with three-wire sys­tems, tie Pins 1 and 3 together on the D4M connectors. These pins are the common conne c tion.

4) If all interfaced systems are to be on the ~ intercom channel, just input one Clear-Com line to the IF4-4, using the D3F connec­tor associated with Interface #4 (the rear panel is labelled to indicate this Party -Line connec­tor) • Then set all the "Party Line/Direct" toggle switches on the rear panel to the "Party Line" setting. See Figure 1, Diagram A.

III. OPERATING CONTROLS

Each interf ace d system is associ­ated with three contro l s on the IF4-4 front panel: Transmit, Re­ceive, and Sidetone.

The Transmit control adjusts the volume level of the Clear-Com sig­nal as heard by the 3-wire or 4­wire system operators.

The Receive contro l adjusts the speaking volume l ev e l of the 3­wire/4-wire system us e rs, as heard by the Clear-Com users.

The Sidetone control prevents the 3-wire/4-wire system operators from hearing each other when they're interfaced with separat e Clear-Com lines.

5) If you want each 3-/4-wire sys­tem to be on a separate intercom channel, input four different Clear-Com lines (e.g., Channels A-D) to the four "c-c Li ne" connectors. Set the "Party Line/Direct" toggle switches to the I~irect" setting. See Figure 1 , Di ag r am B.

6) Other combinations are possible; for instance you can put one camera operator on Channel A, another one on Channel B, and two more on Channel C. To do so, input one C-C line (such as Channel C) to the Party Line D4F connector, connect the two came­ras to Interfaces #3 and #4, and set the #3 toggle switch to "Party Line." Input separate Clear-Com Channels A and B to the C-C line inputs for Inter­faces #1 and #2, set both toggle swi tches to "Di rec t," and con­nect the other two cameras to the D4M inputs. See Figure 1, Diagram C.

Setting the Side tone Levels After you' ve input the Clear-Com lines to the IF4-4, but BEFORE you connect the three- or four-wire systems to the interface:

1) plug a standard Clear-Com head­set into the D4M connector for Interface #1 (on the IF4-4 rear panel) .

2) turn the Transmit control and the Receive control for Inter­face III all the way ~ (fully clockwi se).

3) put on headset and talk into the mic while turning the Sidetone control for Interface III clock­wise. As you turn it, it will

3

Setting the Sidetone Levels, continued

3) be more difficult to hear your 4) unplug the headset, then plug it own voice in the earphones. Set into the D4M connector for In­the control for maximum null, or terface #2. Repeat Steps 2 and 3 the point at which you cannot described above; then do the hear your voice in the earphones same for Interface #3 and Inter­as you talk. face 114.

IV. SPARE PARTS

Clear-Com can supply you with any or all of the following replacement parts for the IF4-4. Please call your dealer or the factory (415) 861-6666 for price and ordering information.

Part n Part Description Qty. Location 240017 Handle, chrome, for 1.75" rack 2 front panel 240025 Knob, Piher, red 4 front panel 240026 Knob Piher, green 4 front panel 240027 Knob, Piher, blue 4 front panel 470035 Trimpot, 50k 4 internal 510044 Switch, toggle 3 rear panel

v. SPECIFICATIONS

Transmit Level: Adjustable, -30 to +14 dBm Transmit Impedance: 600 ohms Receive Level: Adjustable, -30 to +20 dBm Receive Impedance: 10-15k ohms

Frequency Response: 200-15k Hz 6 dB down Minimum Sidetone Balance: 30 dB Distortion: .5% THD Power Requirements: +30 volts DC @ 38 mA (all 4 interfaces)

Connectors: (4) 3-pin XLR female, Clear-Com line (4) 4-pin XLR male, 3- or 4-wire interface line

IF4-4 FOUR-W IRE IRTERFACE ADDENDUM TO OPERATION MANUAL

Please note: If you are NOT using all four interfdces on the IF4-4, the Transmit and Receive level controls for the unused channels must be turned all the way down (full null), or the unit will exhibit oscillation.

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