EXTRA-70 432 MHz Contest Preamplifier

By Gyula Nagy, HA8ET 

 

Introduction

 

The EXTRA-70 432 MHz Contest Preamplifier has been developed based on the experiences with EXTRA-2 REV6 144 MHz Contest Preamplifier. During the simulations and optimizations I achieved that the preamp can be well applied for DX, EME and Contest purposes, as well.

You have to adjust the GAIN not to overload the stages of the transverter or the transceiver. The preamplifier can be fed through a capacitor or a coaxial cable. The +12V supply voltage is needed for the preamp only in RX period.

 

Technical data:

Frequency range:…..……430-440 MHz

Input/Output impedance:  50 Ω

Gain:………….………… 10-16 dB (adjustable)

Noise Figure………..……<0,6 dB (typ. 0,5)

S11:…………………….. -4,7 dB @ 435 MHz

S22:……………………..-27,3dB

1 dB Bandwidth:……….. 13,95 MHz

3dB Bandwidth:………..  19,26 MHz

IP3………….……………>27 dBm

Broadcast rejection:……..>63 dB @ 100 MHz

Rejection @ 144 MHz:…>50 dB

Unconditionally stable

Stability factor:…………>2

Moderate sensitivity to ESD

Supply voltage:……...…  +12…15V/152mA

Powered through antenna feed line, or separately

+40 dBm IP3 GaAs FET (ATF-53189)

Connectors:…………...... BNC or N 

Dimensions (Box):…….. 74 x 37 x 30 mm

 

 

 

Simulation:

 

 

 

Measure:

 

 

 

 

Schematic diagram

 

Part list

 

PCB: The layout of the PCB can be found below. Dimensions are 72 x 34,5 mm

 

 

 

Available completed and tested:

- With N male / N female connectors
- With N female / N female Connectors

- With BNC connectors

-Pretuned PCB without box and connectors

Contact me!