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MODEL NO: NHG-PA-100400-100




General: Project involves design, development and supply of VHF/UHF Power Amplifier, Model: NHG-PA-100400100, operating in 118 to 174 MHz and 225-400 MHz, delivering 100 Watts CW/PEP into 50 ohms load. The amplifier is capable of linear amplification of AM/Non-AM R.F. Signals. Realization of Power Amplifier is by multi-stage amplification using linear amplifiers operating in Class A(low power stages ) and Class B (high power stages),

The Power Amplifier Unit operates on 230V, AC, 1Φ, 50Hz supply. Necessary 24 Volts and other D.C. Supplies within the unit. The Power Amplifier is capable of operating into 2:1 load (with respect to 50Ω) at 1:3 (Tx : Rx) duty ratio. The R.F. Circuits are enclosed in metallic housings (connectorised modules) for ease of assembly / maintenance and testing. The Unit employs *D.C. operated (why not AC fan) fans for forced cooling of circuits

Technical Specifications: All specifications shall be valid for: (a) 230Volts ±15%, 50Hz (b) -20°C to +55°C (c) After 8 hours continuous run-in at 1:3( Tx :Rx ) duty cycle




Frequency of operation

2 3

RF INPUT signal format Duty cycle

4 5 6

Load Impedance Power consumption Power output CW AM FM, FSK Modulation capability in AM mode

108-155.975 MHz * VHF 156-173.975 MHz VHF 225-399.975 MHz UHF *Transmitter is inhibited from 108-117.975 MHz CW, AM, FM, FSK, phase modulation, pulse modulated 1minute transmit ON 3minute transmit OFF 50 ohms, Nominal To be specified by vendor



Modulation Distortion


Modulation Response

10 11 12 13

Incidental FM in AM mode Incidental AM in FM mode Carrier to Noise Ratio(AM/FM) Harmonic rejection


Discrete non-harmonic spurious rejection Output Noise floor(Quietening) Closed loop Amplifier Rise time for pulse input Closed loop amplifier Fall time for pulse input Input RF power for rated power output Input VSWR AC voltage input Response time of ALC and protection loops

15 16 17

18 19 20 21

100 watts ±1.0dB 100 watts (PEP)±1.0dB @ min 85% DOM 100 watts ±1.0dB In AM, when fed with an input AM signal of modulation frequency 300Hz to 3500Hz, with a Depth of modulation of 85±5%, the amplifier shall faithfully reproduce the same at its output In FM, when fed with an input frequency modulated signal of modulation frequency 300Hz to 3500Hz, with deviation of 5.5KHz±1KHz, the amplifier shall faithfully reproduce the same at its output Demodulated modulation distortion shall not be more than 5% at 85 % in AM and @ 5.5Khz±1KHz in FM over the modulating frequency of 300Hz to 3500HZ AM: For a depth of modulation of 85±5%, the demodulated audio output shall be within ±2dB with reference to the level at 1KHz FM: For a deviation of 5.5KHz±1KHz at the output of the amplifier the demodulated audio output shall be within ±2dB with reference to the level at 1KHz 0.2KHz at 80% 1KHz,AM 0.2% at 5.5KHz ± 1KHz,1KHz FM 60 dB min The level of Harmonic radiation will not exceed -60dBc up to 4times the fundamental frequency -80dB -90dB 150 µ sec 150 µ sec 0dBm±3dB Maximum 1.8:1 at 50Ω 230 Volts ±15%, Single Phase, 50Hz. Fuses to be provided 200 µ sec






Output VSWR

24 25 26

VSWR tolerance Linearity Protection


Interface Signal Input(TTL)

28 29 30 31

Size Weight Cooling Connectors(front panel)


MTTR (Mean time to Repair) MTBF (Mean time between failure)

Unconditional stable. Unit shall not oscillate for any condition of load or source impedance Full power in to 2.0:1 load VSWR Power degradation for load up to 3.0:1 & shutoff beyond. (Provision for PA reset) Shall withstand infinite VSWR condition Two tone third order IMD-25dBC Thermal overload, over drive, over current ( Provision for reset on occurrence of any) (a) VHF/UHF command (b) Tx/Rx Command (c) ALC Slow/Fast (d) AM/Non AM 19 inch Rack compatible. 178x483x489 mm Not more than 10 Kg Internal forced air RF Input N type female RF output N type female 25 pin circular type interface connector at the back 30 minutes


1000 Hrs.