WA5BDU - Nick Kennedy's
Ham Radio Page

Photo: WA5BDU in hamshack

I've been enjoying the hobby of ham radio since being licensed as WN5BDU in January, 1962 at the age of thirteen.  I've enjoyed many facets of this diverse hobby over the years, but I remain mostly a CW (Morse) operator.  On the air activities include casual QSOs and competitive events such as contesting and a bit of DX chasing.  Off the air, I'm building stuff or writing microprocessor code.

I've lately spent a lot of time involved with a development in ham radio which emphasizes small, simple (usually) low powered radios, called the QRP movement.  QRPers tend to use CW a lot and also like to build equipment from kits or from scratch.  The technical side appeals to me.

I sold the fine FT-1000 and purchased the K3 in early 2008.  It's exciting to have a new transceiver.

My Rig - Current Equipment

  • Elecraft K3 my main HF rig
  • Hallicrafters HT-40 1960s novice tranmitter
  • Drake 2B classic tube receiver with 2BQ
  • Heath VF-1 classic VFO from 50s & 60s
  • K8RA mini paddle
  • KT-34A 4-element triband beam at 48 feet
  • Lots of home built radios
  • ICOM IC706-IIGX for mobile & VHF
  • W6AAQ screwdriver antenna for HF mobile
  • Ten-Tec PowerMite vintage QRP rig
  • ATS-3 sophisticated QRP rig in an Altoids tin
  • Kent & Brown Brothers keyer paddles
  • 180 ft dipole fed with 450 ohm ladder line
  • Johnson Matchbox classic tuner for above
  • Quarter-wave inverted-L for 160 meters

History: My older radios and times


Technical stuff - my projects

One-chip receiver A 40 CW meter receiver using the TDA1073 AM radio chip
 EFHW Antenna Matchers
The end-fed half-wave antenna is enjoying popularity for portable
use due to its ease of erection and no-feedline design
Here are two matching circuits for the EFHW
Introduction to LTSpice (pdf)
Introduction (Microsoft Word)
Tutorial #1
Tutorial #2
LT Spice is a free circuit analysis program.  It's easy to use but there
is the usual initial familiarization problem.  The link at the left is a PDF
file of  my introtuction and tutorial.  Download from the link below:
Permeability (current) controlled oscillator A simple circuit from EDN which varies the frequency of
an oscillator by passing current through a toroid, changing
its permeability by saturation.  The result shows up in the
frequency of the oscillator.
Amplifier to boost DDS output I have an NJQRP DDS and another designed by K6ESE both of which
put out a couple milliwatts of RF power.  This circuit boosts that to
about 5 watts for use as a QRP transmitter or to allow the DDS to drive
a tube-type transmitter.
A 60 meter SSB transmitter This is a 10 watt SSB transmitter I designed and presented at
OzarkCon in Joplin in 2005.  
A simple autodyne receiver An interesting receiver that can lock to the station being
received (such as WWV).  
Thermostatic fan control for MFJ-4225MV P/S A circuit to allow the fan in the MFJ-4225MV (or other) power supply
to run only when needed, which quiets it down a lot.
Some mods to KD1JV Butterfly source for DDS Steve Weber made his source code for the Atmel Butterfly demo board
available for users to modify.  I added the ability to toggle between the
AD9850 and AD9851 versions of the NJQRP DDS boards plus the
ability to use a rotary encoder for frequency control.
Crystal characterization and filter design From a presentation I gave at OzarkCon in Joplin, Missouri in 2008
1-bit sine generation with a PIC MCU Just for fun, generating a sine wave with an 8-pin PIC

Like Morse Keys?
Check out my key page
Tiny Photo of J-38

My Morse Key Page