UHF Wireless IFB Transmitter Base Station

  • 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


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

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

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

100kHz (0.1MHz)

Spurious & Harmonic Suppression: 37dBc above 1GHz

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

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

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




5.25 (including connectors) x 3.25 x 1.25in (LxWxH)

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 manual:

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) requirements.

Associated Products

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