This
chapter presents articles, essays and features dealing with
technical, operational, regulatotory and historical aspects
of
radio. The layout of some of the available PDF files is my
reminiscence of
the "ham radio" (HR) magazine, which was founded by Skip Tenney, W1NLB,
and Jim Fisk, W1HR/W1DTY and published from February 1968 to June 1990.
In its time HR was the preeminent technical magazine for amateur radio,
it had no peers and to this day published some of the most cutting edge
articles in amateur radio history. Feel free to download and circulate
any of the material presented here ...
SHORT END-FED DIPOLE ANTENNA
See my patent paper for
a Short
End-Fed Dipole Antenna
on the servers of the German Patent Office (patent
number DE 103 22 186 B3, granted on 02.12.2004, in German only).
It has many advantages over a common center-fed dipole and I
encourage all readers to build their own version of my practically
proven antenna design for personal non-commercial use. If you do so,
please contact me for important notes on the BalUn !
THE CODEPHASER 
Add
a new dimension of CW perception to your receiver by incorporating
this simple audio device for pseudo-stereo reception of radio
telegraphy signals. The sound does not seem to originate from the
earphones as usual, but from inside your head. Multiple CW signals
within the receiver passband seem to be spreaded out holding specific
positions while static crashes appear randomly distributed throughout
the entire space - a spatial sound sensation with depth and presence
that
makes CW copy unique ...
I
recorded a few moments on the 40m band to demonstrate
the effect of the CODEPHASER.
Before you listen to the demo, please note that it is
absolutely
necessary to use stereo headphones - PC loudspeakers definitely don't
work ! Do not expect any astounding effects, since spatial
sound
sensations are the normal condition for our auditory
system.
Close your eyes while listening in order to focus exclusively on
the sound. And certainly it will take some time and
several listening sessions before you can fully appreciate
this new
dimension of CW reception. The demo consists of 9 radio clips :
Clip
#1 (39 sec.): Sweep across the 40m CW band. The clip starts monaural,
after 15 sec. the CODEPHASER is switched in and the
signals now
appear on the right moving to the left with increasing pitch
...
During the
following clips, the CODEPHASER is switched in and
out alternately (the switching moment can be identified by
a short popping noise):
Clip
#2 (18 sec.), Clip #3 (30 sec.), Clip #4 (31 sec.): CW pile-ups. A wide
filter is used to enhance the spatial effect. Pay
attention especially to G3PHO in the first and F6COW in the
last
pile-up ...
Clip
#5 (16 sec.), Clip #6 (19 sec.), Clip #7 (10 sec.): FSK-signals.
Though it makes no sense to listen to them,
they sound
quite interesting through the CODEPHASER
...
Clip
#8 (18 sec.), Clip #9 (18 sec.): SSB-signals.
Please listen now to
the CODEPHASER
sound demo
MAGNETOSPHERIC
DUCT ECHOES
Sometimes,
at rare occasions in the night during the winter months and
predominantly on the 80m-band, very few radio amateurs are lucky enough
to observe a strange and most thrilling phenomenon: they can hear the
echoes of their own transmitted signals, delayed
by much more time than a trip around the globe would take.
Please
don't hesitate to download my simple computer program mde.exe
which explains Magnetospheric Duct
Echoes (MDEs), calculates path
lengths and time delays specifically for your location and contains a
short bibliography on that topic. This small self-explanatory program
(95 KB) is absolutely save to use on any Windows platform
and does
neither generate nor touch any files on your system. Always keep a
recording device attached to your transceiver and ready to go - who
knows, maybe you are one of those few lucky radio operators
who ever experience these rare echoes ...
IEC/CISPR
THREATENS RADIO SERVICES
CISPR
is the Special
International Committee on Radio Interference of the International
Electrotechnical Commission IEC with central office in Geneva,
Switzerland. It is concerned with the development of standards
regarding electromagnetic interference and most of these are adopted by
the European Union and many other countries. Disturbance limits for
Power Line Telecommunications (PLT) systems are defined by the standard
CISPR 22 and its European equivalent EN 55022 entitled "Information
technology equipment - Radio disturbance characteristics - Limits and
methods of measurement". Read my report describing why and
how CISPR and the PLT lobby threaten the Radio Services ...
IEC/CISPR
Threatens Radio Services by a Planned 18 dB Relaxation of PLT
Disturbance Limits (Part 1)
CISPR
Project Team Dominated by PLT Lobby - Rationale Behind Proposed
Approach Disproved (Part 2)
To
be continued - stay tuned !
THE
COOTIE, SIDESWIPER OR DOUBLE SPEED KEY
Being
a passionate CW
operator, after 35 years of mainly high-speed operation with electronic
keyers I felt more and more bored listening to the uniform and
impersonal sound of CW signals on the amateur radio bands. So in March
2008 I found myself a new challenge: to build and learn to operate a
Cootie key. The picture shows my homebrew Cootie key #1. Please note
that this is NOT a paddle to operate an electronic keyer, and it is
also NOT a semi-automatic key or "Bug" ! In fact, the dots and dashes
are both made manually by horizontal movement of the blade. The
resulting CW note has to be heard to be appreciated - if properly
operated, it sounds very distinct, melodic and a little bit corny ...
Between March and October 2008 I made all my CW QSOs with this Cootie.
Though I enjoy it very much, my main key is still
electronic ("CMOS Super Keyer II" with a homebrew
Sensor-Paddle which works much better than common sensors by utilizing
the capacity of the human body instead of the skin resistance ...)
simply because I love too much to have long conversations at
speeds around 40 wpm, which is quite impossible with
a Cootie. However, operating it makes a lot of fun, is a most
natural way of sending morse code, and learning to really master it is
a true challenge. So you can hear me on the air - not always
but soetimes - with my sweet sounding Cootie ...
HOW
THE MICROVERT REALLY WORKS
Extremely
small and highly
efficient - These two properties of a fictious superantenna sound very
attractive, not only to us radio amateurs. Unfortunately, they are
physically competing since the smaller the antenna copared to the
wavelength, the smaller the radiation resistance. And because in real
antenna systems the losses increase with decreasing radiation
resistance, efficiency drops with reduction in size. See my detailed
analysis of the DL7PE-MicroVert and it's derivatives and learn how the MicoVert really works
(in
English and in German).
A NEW EQUIVALENT
CIRCUIT FOR THE IMPEDANCE OF SHORT RADIATORS
In
1973 the two scientists
Friedrich Landstorfer and Hans Heinrich Meinke of the University Munich
published a highly interesting article that explains the division of
the total antenna capacitance into so-called space capacitance and dead
capacitance very clearly both in quality and in quantity on the basis
of the time-dependent course of wave detachment in the near field of
antennas - a subject which has been intensively addressed by Prof. Dr.
Landstorfer with many interesting publications. They show why and how
the radiation resistance and as a result also the efficiency are
decreasing with shortening of a radiator, why for a rod of uniform
diameter that diameter has no influence on the radiation resistance and
how constructive measures affect efficiency. Download the German
original "Ein
neues Ersatzbild für die Impedanz kurzer Strahler"
(PDF,
1037 KB) or my English translation "A New Equivalent Circuit for
the Impedance of Short Radiators" (PDF,
322 KB).
POYNTING VECTORS
Where
on an antenna does
radiation come from ? If you are one of those searching minds intrigued
by this big question, read the explanation on the Poynting vector and
energy flux in electromagnetic wave fields as part of my analysis how the MicoVert really works
(in
English and in German) and watch my little movies Poynting #1
and Poynting
#2. They
visualize the electromagnetic energy flow around a dipole transmitting
antenna in free space, represented by a Poynting vector field. The
movies start to run with normal speed as soon as the picture is
completely downloaded. Watch very carefully since it takes time before
some most interesting details become obvious ... (Animated GIFs, work
only if viewed with a web browser, best resolution: 1024x768).
REFLEXIONEN
UND VERLUSTE AUF ÜBERTRAGUNGSLEITUNGEN (in
German only)
Welche
Betriebszustände kann eine Übertragungsleitung annehmen ? Was ist eine
konjugiert komplexe Anpassung ? Wie kommt die Totalreflexion auf ihrer
Lastseite zustande ? Warum kann die Vorwärtsleistung auf einer Leitung
höher sein als die Ausgangsleistung des Senders ? Wie funktioniert ein
Reflektometer ? Welche Verluste entstehen tatsächlich auf der Leitung ?
Das alles und mehr wird hier
erklärt ...
THE
INVENTOR OF
THE COMMON-MODE CHOKE
"common-mode
choke", "current
balun", "Guanella balun" or "1:1 Guanella" are different names for the
same device which is widely used in electronic engineering to force
balanced RF currents. It is generally claimed that it was invented in
1944 by the Swiss Gustav Guanella - Fact
is, however, that this device has been already invented and patented in
1932 (patent #592184) by the German Felix Gerth
for the company "C. Lorenz Aktien-Gesellschaft in Berlin-Tempelhof".
There is no doubt that it was an ingenious idea by Guanella to use that
common-mode choke as the basic building block for his transmission line
transformers in later patents, with ports connected in parallel on the
low-impedance side and in series on the high-impedance side. But the
common-mode choke itself is the true brainchild and invention of Felix
Gerth. Here are some translated excerpts from Gerth's patent paper:
"High-frequency
engineering utilizes energy transmission lines which are comprised of
two parallel conductors carrying high frequency in anti-phase so that
their external fields compensate and no radiation is present. If,
however, the geometrical lenghts of these energy transmission lines are
in the order of a wavelength with external fields being present, it is
possible that the conductors also carry in-phase currents in addition
to the anti-phase currents. This is the case, for example, in
arrangements which are used to feed antennas ... These in-phase
currents result in radiation of the energy transmission line ... In
order to prevent these drawbacks, it is suggested to include means by
which anti-phase currents are allowed to flow unhindered through the
parallel conductors whereas in-phase currents are hindered ... an
arrangement of coils is inserted which consists of two coils wound into
each other in the same sense thus being tightly coupled. The
inductivities of the coils cancel for the anti-phase currents from the
transmitter so that energy flow in that wanted direction is unhindered.
But for the in-phase currents which are induced by emission of the
antenna the inductances sum up so that these currents encounter a high
resistance and thus are hindered ..."
EMC
The
European Commission
considers the protection of radio services from harmful interference
caused by electrical aparatus of any kind as embodied within the
Constitution an Convention of the International Telecommunication Union
(ITU), which represents international law, to be an obstacle to trade
and market. With her new directive 2004/108/EC on electromagnetic
compatibility (EMC) she tries to grossly cut down the protection of
radio services for the benefit of neoliberal political objectives. The
German federal ministry for economy and technology (BMWi) even goes one
step further - and steps the mark - with it's bill for a new national
electromagnetic compatibility act (EMVG), which is an attempt of the
subordinate federal regulatory authority for telecommunications
(BNetzA) to get rid of her liability for the protection of all radio
services. The bill infringes not only the ITU Radio Regulations and
thus international law, but also the EMC-Directive of the European
Council itself. Here are my comment
and petitions
on that bill for download (in
German only).
QTC DL (in
German only)
Mitteilungsblatt
für den Amateurfunkdienst - Archiv
mit allen Ausgaben zum Download