Gary ZL1AN, Auckland, New Zealand
I've been a Ham since 1960. I'm a life member of the NZART.
I write the "Morseman" column for the NZART journal "Break-In”. This started as a column about CW, but I cover a lot of other topics as well.
I post comments, derivations, and interesting problems raised in my column on this web-site..
Below are links for downloading PDF files. Below these, see links to software I’ve written.
Bruene SWR bridge. Theory and design of this common SWR indicating network.
Transmatches. Theory and design of pi and tee RF transmatches.
Resonant matching networks: Chapter 1 of my Network text.
pdf files: See brief descriptions below.
Tuned matching networks:
Chapter 1 of my text on Network analysis.
This develops the design of theTee and Pi networks used in transmatches, and derives simple approximate expressions for estimating their losses.
Ron ZL1TW's Crystal Oscillator:
A common crystal oscillator is based on the Clapp circuit, derived from that of the Colpitts. I discuss the circuit, derive oscillation conditions, and show the results of an LTSPICE simulation
The Bruene Directional Coupler and Transmission Lines:
Operation of the classical Bruene SWR bridge is usually described in terms of forward and reflected waves. But it operates equally well when terminated in a lumped component, such as a resistance, or impedance. This is not obvious, and is widely misunderstood.
Downloadable Programs:
Doktor displays the closure pattern of Morse sent with a button of a computer mouse plotted against time.
The elements are identified, and their average durations, ratio, weighting, and estimated speed are shown, with comments.
An algorithm estimates two “merit” parameters and shows them as numeric values, “100” being “perfect”
A real Morse key can be connected to the mouse leads for a realistic practical estimate. Download from link below.
Teach is an application to teach Morse code reading. The algorithm is adaptive, responding to keys pressed by the user.
New characters are introduced when sufficient familiarity with those currently in use is shown. Adjustable Farnsworth spacing can be implemented.
For final practice, 950 supplied texts can be played at any speed and audio frequency, or any other texts may be loaded from disk by user.
Andrew, ZL1AF, has enhanced and recompiled this version using the Lazarus compiler. Download it here:
A link to my original site, frozen in time because I can’t edit it any more. More early files and software can still be downloaded from here.
References: Latest “Morseman” column
[1] Video:
[2] Fists Down under:
[3] Antique radio dials
[4] Morse code heard everywhere
[5] ZL1AN Website: You’re looking at it.
[6] Sideswiper Cootie Key
[7] History of Morse key
[8] The first transatlantic cable
..