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- A QRP regulated power supply
- A battery power supply for the radio shack
- Solar cell charging, low drop-out regulators
- Battery powered shack lighting
Chapter 9
ACCESSORIES FOR THE
TRANSMITTER
- A straight key
- An electronic bug
- Building dummy loads
- "T" type antenna coupler
- A low pass filter
- How to stay legal with a homebrew transmitter
- Antenna and power relays
- Homebrew QSL cards
Chapter 10
VARIABLE FREQUENCY
OSCILLATORS
- Drift is a big deal today
- Low frequency VFOs drift less than high frequency
VFOs
- JFET transistors
- The oscillator circuit
- The buffer, final amplifier and output filter
- The 50 secrets of avoiding drift
- JFETs, single-side PC boards, cast metal box,
multiple NPO caps, small variable caps, precision voltage regulation
and more
- Vernier tuning
- Varactor tuning elements- advantages and disadvantages
- A precision power supply
- A voltage doubler power supply for battery use
- Square wave generator with a multivibrator
- Squaring up the square wave
- Charge pump, diode/ capacitor voltage doubler
- Schottky diodes for efficiency
- Temperature compensation methods
- Positive coefficient capacitive trimmer compensation
- How to adjust the compensator
- Thermistor/ varactor temperature compensation
Chapter 11
Building a VFO for
the higher bands (PMOs)
- Old approaches that no longer work
- Frequency multiplication
- High frequency oscillators
- PreMix Oscillator method of frequency translation
- A VFO-controlled QRP module
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- Crystal oscillators are stable, aren''t they?
- Crystal oscillator circuits
- Butler oscillators and big crystals
- Mixers, bipolar transistor and dual-gate MOSFET
- Optimum drive requirements
- Direction of tuning, drift error cancellation
- Multistage filters and filter/amplifiers
- The QRP final amplifier stages
Chapter 12
FINAL AMPLIFIERS
- The basic features of a modern linear power amplifier
- It looked easier in the Handbook
- Linear "noise mode" operation
- A tuned 50 watt class B amplifier
- Ferrite balun transformers
- An untuned, sort-of-linear, class B, amplifier
- Keying the 50 watt transmitter
- A linear Class AB amplifier, this time for sure
- Single Sideband (SSB) needs a linear
- Biasing without thermal runaway
- Clamp diodes prevent runaway
- Mechanical construction
Chapter 13
BUILDING A HOMEBREW
HF RECEIVER
- Building a receiver - an unusual adventure
- What's a reasonable goal?
- An "adequate performance" HF communication
receiver
- Does it have to be so complicated?
- Planning your receiver
- Direct conversion versus superhetrodyne
- Why not single conversion?
- Start with a single-band, single-conversion superhetrodyne
- How do modern digital receivers do it?
- Receiver construction- build with shielded modules
connected by thin coax.
- The 80 meter preselector
- Reception on 80 meter and 160 meters is aided
by a tuned transmatch
- The Variable Frequency Oscillator
- Mixer magic
- Mixers will give you lots of static- and howls
and squeals
- A practical homebrew mixer made from discrete
parts- it's harder than it looks
- Dual gate MOSFET mixers
- Not all MOSFETS work equally well
- Crystal ladder filters- essential for CW
- All 9.000 MHz crystals aren't equal
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