EME201 HF Amplifier Module
The Mini-Kits EME201 HF Amplifier module is part of the M1 series building blocks to construct a high performance M1 HF Transceiver. The M1 HF Series Kits have been designed to allow easy construction due to the use of mainly leaded components for those that don't like surface mount devices. Modern SMD components are only used when required due to availability of components, or for better performance. The RF modules are all designed with a 50ohm impedance making it easy to interconnect with the other M1 series modules, and your own homebrew circuit designs.
The Amplifier can be used as a general purpose 10dB receive pre-amplifier, or low power TX driver for use between 500kHz and 60MHz. The amplifier is a standard design using a single high FT transistor with both emitter degeneration, and feedback from the collector to base to obtain a flat wide 1dB bandwidth from 500kHz to 60MHz. The design incorporates PIN diode switches to allow RF bypassing of the amplifier for receiver applications, and the same amplifier to be switched for use as a TX driver amplifier. See the Block diagram for the connections to this module.
The amplifier has been designed with a gain around 10dB , and has a
measured 4.4dB noise figure at 12MHz. The output IP3 which is
important for strong signal handling was measured as +30.5dBm @ 7MHz
using two tone signals of 9 and 11MHz. The amplifiers 1dB
compression was measured as +14.5dBm @ 7MHz. Changing the 20mA bias
of the amplifier to 50mA increased the OPIP3 to +40dBm and a 1dB
compression of +21.5dBm at 7MHz.
The images below show both sides of the board. The amplifier is very easy to construct as it mainly uses conventional leaded components. There are a few SMD components on the bottom side of the board which are quite easily fitted. The Transformer TF1 is easily would using 10 turns of 0.3mm bi-filar wire on a T37-43 Toroid. The Toroid can be secured to the board with hot melt glue, or non acidic silicone if required..