5W AMP HF Packer PreAmp Model PA-100 Home Construction Project
This project parts and your efforts will eventually provide
you with a compact 0.1 watt input to 5 watt output linear amplifier for use with QRP SSB/CW transmitters on the amateur bands 160 through 10 meters and which can be powered from a 12 volt DC supply. The design is a good balance between output power, physical size and battery power consumption. The completed amplifier will reward the builder with a clean, more powerful output signal for a QRP rig when radio conditions become marginal.
This project is not a beginner's project and requires a medium skill level to complete it successfully. Builders require soldering, hand tool, basic electronics and component identification skills.
The Model PA-100 amplifier module may be mounted within a SDR box thereby keeping the heat and RF out of the computer box and provide a suitable drive signal for the HF PROJECTS HF SuperPackerPro 100W Amplifier. The amp may also be optionally mounted in a stand-alone Bud Box case with the companion HF PROJECTS Low Pass Filter module. In this mode the drive input may be increased to a maximum of 1W at
the gates of the MOSFETs. The Pi Resistive Attenuator (R2-R4) may be custom computed for the desired input drive level.
Size 3.7 x 2.4 x 1.4” (LWH, including heat spreaders and spacers)
Weight less than 3 oz. When populated
Supply voltage 8.5 to 15 VDC (13.8V nominal); no reverse-polarity protection;
Current drain, Standby approximately 30mA
Transmit 1-1.3 A at 8 Watts
Filter Selection 6-position rotary switch (ext filter reqd)
Frequencies 160, 80, 60-40, 30-20, 17-15, 12-10 M
Control Standby/Operate, PTT
Input 2-pin Friction lock plug 0.1” 50 ohm
Output 2-pin Friction lock plug 0.1” 50 ohm
Power cable 2-pin Friction lock plug .156”
Drive requirement 0.1 watts RF (with internal 0.1dB pad)
Power output 3-8 watts RF 160 – 10 meters
Duty cycle Designed for intermittent SSB service
Forced air 100%
Spurious products -40 dB or better @ 5 watts w/ext filter
Harmonic content -45 dB or better @ 5 watts w/ext filter
Load tolerance 2:1 or better SWR recommended
T-R delay approximately 0.2 second
Control RF sensing or isolated PTT T-R relay
Specifications above assume a 13.8 VDC supply and 50-ohm load at the antenna.