• UHF wireless IFB Transmitter basestation
  • Operate between 486.4 and 639.9MHz
  • Stand alone or rack mountable with the PRK-2 kit
  • Selectable Low-Frequency roll-off
  • “Locked” setting prevents accidental changes
  • Overcomes channel noise and compandor artifacts
  • Tough machined aluminum case housing

NOTE: This product is not approved for sale in Europe.

Item Part Number:

PTX3-19 (Block 19: 486.4 to 511.9 MHz), PTX3-21 (Block 21: 537.6 to 563.1 MHz), PTX-3/D (Block 24: 614.4 to 639.9 MHz) This block is targeted to be banned by the FCC for use within the US by July 13 2020

Technical Specifications

Operating Frequencies

486.4 to 639.9MHz

Block 19: 486.4 to 511.9 MHz
Block 21: 537.6 to 563.1 MHz
Block 24: 614.4 to 639.9 MHz*
*This block is targeted to be banned by the FCC for use within the US by July 13, 2020.

Frequencies Channels (per block)


Channel spacing

100 kHz (0.1 MHz)

Spurious & Harmonic Suppression: 37 dBc above 1 GHz

Frequency Stability: ±.001% (10 ppm) @ 25ºC

Temperature Stability: ±.001% (10 ppm) from -30º C to +50º C

Channel Selection: Momentary pushbutton switches, TUNE UP and Down

Compatibility Modes: IFB, Digital Hybrid Wireless; 400 Mode, 200 Mode, 100 Mode, Mode 3, Mode 6

Pilot Tone: 29.997 kHz IFB Mode, 32.765kHz; 200 Mode, 400 Mode step selected, 32.768kHz Mode 6

Modulation: FM, ±20 kHz deviation IFB & 100 Mode, ±75kHz 200 & 400 Mode, ±50kHz Mode 3 and Mode 6

Audio Frequency Response: 100 Hz to 8 kHz, ±1 dB, IFB MODE system response (see Rolloff), 30Hz to 20kHz ± 1dB, 200 & 400 MODE system response (see Rolloff)

Rolloff: Low frequency audio rolloff is Menu selectable for 3 dB down at 35 Hz or 50 Hz

Signal to Noise Ratio: 90 dB typical (“A” weighted)

RF Power Output: 250 mW (nominal)

Output Impedance: 50 Ohms

Audio Input Levels: 0 dBu for Line, RTS1 & RTS2, -10 dBu for Clear-Com, and -42 dBu mic dry inputs, +/-50VDC max

Audio Input Config: Balanced and Unbalanced, rear panel selectable for Line, Mic, RTS 1, RTS 2 and Clear-Com

Audio Input Impedance: Greater than 2 K balanced, greater than 1K unbalanced at any gain setting

Control Range: -18 dB to +24 dB (0 dB nominal center), software selectable

Audio Input Jack:  Standard XLR female connector

Input Power:  12 to 14 VDC typical, 200 mA max; Max input range 6 to 18 VDC

Power Input Jack: Coax type, locking LZR RL26AE

Indicators: Backlit Liquid Crystal Display. Displays modulation meter, frequencies, modes, rolloff, audio level, and tuning groups

Front Panel Controls

MENU momentary pushbutton switch
Power OFF-TUNE-XMIT, 3 position slide switch
Select Up momentary pushbutton switch
Select Down momentary pushbutton switch

Rear Panel Controls: Input Mode Select, 4 section DIP switch



Size: 5.25” long (including connectors) x 3.25” wide x 1.25” high

Emission designator: 180KF3E

The T4 IFB transmitter is FCC type accepted under Part 74:470 –
608MHz and 944.1 – 951.9 MHz

The FCC requires that the following statement be included in this

This device complies with FCC radiation exposure limits as set forth for
an uncontrolled environment. This device should be installed and
operated so that its antenna(s) are not co-located or operating in
conjunction with any other antenna or transmitter. A separation
distance of at least 20cm (8 inches) must be maintained to comply with
the FCC Radio Frequency Maximum Permissible Exposure (MPE)

Associated Products

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