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General Description
The TR series tone remotes are designed to provide remote control of a conventional or trunked two way radio
base station or repeater via a leased wire line, in-house twisted pair or RF link.
The TR series is available in four different housing configurations. They are: the TR10 telephone style unit with
handset, the TR20 desktop console with desk microphone, the TR30 desktop console with built in electret condenser
microphone and the TR40 desktop console with goose neck microphone.
Standard features on all TR models include front panel PTT switch, LED transmit indicator, monitor function,
intercom function, two watt amplified speaker with volume control.
The TR10, 20, 30 and 40 may be wall mounted by ordering the -WM option. When wall mounting the TR20 please
note, no provisions are made for mounting the desk microphone.
TR series units are normally powered by the supplied wall plug-in transformer. The may also be powered from
a 12 volt DC source by removing the wall pack and making the appropriate DC connections to TB1.
Installation
The TR series tone remotes will work with any remote system using the EIA standard tone control format. They
are designed with protection against both power and telephone line surges. This protection circuitry requires a
properly grounded AC outlet be used to power the wall pack. If the remote is to be powered directly from DC, a well
grounded 12 to 16 volt DC supply is required.
Phone lines - The TR series is designed to work with a good quality leased voice grade pair (phone line) or in
house twisted pair wiring.
Parallel operation - When several remote control units are connected in parallel the total system impedance will
decrease to a point where operation is degraded. This occurs when three or more remotes are connected in parallel.
To compensate for this effect, TR series remotes provide a switch selectable 600 ohm or 5000 ohm impedeance.
In parallel remote installations using the same phone line, dip switch 1 should be in the OFF position (5000 ohms),
in all remotes except the last one in the chain. For multi-point installations using more than one phone line the above
procedure applies to each phone line.
Up to ten TR series tone remotes may be connected in parallel. The maximum loss between any remote and the
termination panel must not exceed 20db.
Level Setting
The following adjustments assume that the termination panel has been properly installed.
Line Input - The receive line input, R89, adjusts the audio level to the input of the compression amplifier circuitry.
This allows the threshold of compression be adjusted from -20 dBm to +10 dBm.
While applying an RF signal modulated with a 1000 Hz tone at 60% system deviation to base station receiver,
adjust the termination panel line output control for 0 dbm to the phone line. Adjust each remote as follows:
a. Connect a scope or analog AC volt meter to ground and pin 14 of U2.
b. With R89 fully clockwise, adjust in a counter-clockwise direction until the AC voltage level on scope (approx.
1V peak to peak) or meter (approx. 360 mVrms) just stops increasing. This point is the threshold of compression.
c. Remove the RF Signal from the base station.
Line Out - This level is preset at the factory for 0 dbm out to the phone line and may not require readjustment
at installation. If needed, the procedure is as follows:
1. With the handset off-hook, if applicable, depress the intercom switch and adjust the mod out pot (R63) while
speaking in a normal voice until 0 dbm is measured across the phone line at the termination panel.
2. Move dip switch 7 to the on position and key the remote. Adjust R80 (Tone Level) until the 1950Hz function tone
measures 0 dBm across the phone line at the termination panel.
Notch filter - The 2175 Hz notch filter is factory tuned and should not need readjustment except in the event of
repair. Adjustment procedure is as follows:
a. Apply a 0 dBm, 2.2Vpp, 2175 Hz signal across the red and green phone line inputs.
b. Using a dual channel scope in the X-Y mode, connect one probe to pin 14 of U2, the other to pin 8 of U3.
c. Adjust R39 until the lissajous pattern on the screen closes to a flat line. Remove probes.
d. With the scope in the single channel mode, connect probe to pin 14 of U3. Adjust R38 to obtain minimum signal
