This is very simply preamplifier module with 2N5109 transistor based on W7IUV design. You can use it as high IP preamplifier, buffer amplifier or small driver. Gain is up to 18dB and there is also build in variable ATT. You can easy set gain as high as you need! As well you can set right transistor bias with multi turn potentiometer. Two relays offer bypass switching if there is no power supply.

Applications

* High IP RX preamplifier - RX antennas * Buffer amplifier * Driver amplifier

KIT

Parameters

* Supply voltage 12 to 14 V - HIGHER SUPPLY VOLTAGE NEEDS COOLING AND RESISTORS TO RELAYS!!!
* Supply current up to 180 mA - include relays current

* gain for 50 kHz to 1 MHz

* gain for 1 MHz to 70 MHz

* Input SWR, S11

Schematic

Part List

Part	Value	Device
ATT-TRIM	R 200R	R-TRIMM64W Multi turns Bourns 3296 W
C1	C 100nF	C-EU050-024×044
C18	C 100nF	C-EU050-024×044
C19	C 100nF	C-EU050-024×044
C20	CPOL 10uF/25V	CPOL-EUE2.5-5
C21	C 100nF	C-EU050-024×044
C22	C 100nF	C-EU050-024×044
C23	C 100nF	C-EU050-024×044
C24	CPOL 10uF/25V	CPOL-EUE2.5-5
C25	C 100nF	C-EU050-024×044
C28	C 100nF	C-EU050-024×044
C35	C 100nF	C-EU050-024×044
D1	D 1N4148 DO35-7	1N4148DO35-7
IN	CON SMA	ST-SMB-V
JP1	JUMPER	JP1E
L1	T 5t	FT50-75
L2	T 5t	FT50-75
L3	FR3-FR TYPE	FR type
OUT	SMA	SMA F
R1	R 150	R-EU_0207/10
R4	R 2k	R-TRIMM64W
R5	R 2k7	R-EU_0207/10
R6	R 680	R-EU_0207/10
R7	R 1k	R-EU_0207/10
R8	R 6R8	R-EU_0207/10
R9	R 12R	R-EU_0207/10
RE11	G5V-2	G5V-2
RE12	G5V-2	G5V-2
T1	TR 2N5109	Motorola
X1	Wago	W237-102

!Board

[https://remoteqth.com/img/ZAW-WIKI/preampmodule/brd_v0.1.png}}

!KIT Assembling * Insert two multi-turn trimmers there is 2 kOhms (202) and 200 Ohm (201) * Insert resistors * continue with capacitors small yellow 104 apacitors are 100 nF continue with two blue electrolytic capacitor - PLEASE be careful on polarity! minus (-) is marked on capacitor, plus (+) on PCB * Insert diode, relay and inductor two Omron relays Diode 1N4007 - please follow polarity on PCB small inductor L3 * Insert transistor to the radiator and wind output transformer use screw driver to open radiator a little bit if needed. there is small ferrite core T50-75 wind 5 turns of bifilar wires *Example of the binocular wires :) * please measure start and end of both windings * insert it into the PCB in the right order!

Tunning
* There is nothing to tune on RF side. It is wide band amplifier. * You only need to set right TRANSISTOR BIAS current and Gain. disconnect jumper JP1 connect mA meter there (200 mA scale is fine) connect supply voltage you want - from 12 to 14 V turn the resistor trimmer R4 (BIAS) and set bias current you want - it should be from 60 to 85 mA - depends on application than connect jumper short back again * With the resistor trimmer (ATT-TRIM) you can set amplifier gain as you need. from 0 to about 18 dB turn the ATT-TRIM (201) Doc**
Article from W7UIV in PDF here