Aperture Antennas - Part I : by:
Prof. Natalia K. Nikolova
Dear friends, I would like to give to you an interesting and reliable
antenna theory. Hours searching in the web gave me lots theoretical
information about antennas. Really, at first I did not know what information
to chose for ANTENTOP.
Now I want to present to you one more very interesting
Lecture - it is Aperture
Antennas- Part II
Dipole
Antenna for the 80- meters With Rectangular UR0GT- Match :By:
Nikolay Kudryavchenko, UR0GT
It is an alternative way (compare to DEWD) to design a broadband
antenna- use so called "UR0GT- Match." The match was offered
by UR0GT at 2004 at HZ- Forum. The match was used to feed VHF- Antennas,
but it works at HF too.
Dipole
Antenna for the 80- meters With Triangular UR0GT- Match:By:
Nikolay Kudryavchenko, UR0GT
It is an alternative way (compare to DEWD) to design a broadband
antenna- use so called "UR0GT- Match." The match was offered
by UR0GT at 2004 at HZ- Forum. The match was used to feed VHF- Antennas,
but it works at HF too.
Narrow
DEWD Dipole for the 80- meters with an Inductance Matching:By:
Nikolay Kudryavchenko, UR0GT
It is just a variant of a Narrow DEWD Dipole for the 80-
meters with an Inductance Matching.
The antenna has enough good parameters - Pass Band and Efficiency.
Super
Narrow DEWD Dipole for the 80- meters with A Stub Matching:By:
Nikolay Kudryavchenko, UR0GT
It is just a variant of a Narrow DEWD Dipole for the 80-
meters with an Inductance Matching.
The antenna has enough good parameters - Pass Band and Efficiency.
Simple
Field One- Wire- Length HF Antennas :By:
Igor Lavrushov , UA6HJQ
Below will be described simple one- length- wire HF antennas.
The antennas were designed for mountain's radio- expeditions. The main
criteria were- low weight plus simplicity. All described below HF- Antennas
were tested in Northern Caucasus Mountains with a transceiver FT- 817
and ATU MFJ- 902 and provided good result.
Flat
EH- Antenna for 10- MHz:
By:
Vladimir Kononov, UA1ACO, St.-Petersburg
Some days I heard 10- MHz. Good propagation conditions,
lots stations but no antenna. Only 42- meters length of wire was connected
to my ICOM-7000 through ICOM AT-180. So, I decided to make EH-Antenna
for the band. To avoid too much job with cylinders (that are commonly
used at EH- Antenna) I made a Flat EH- Antenna from stuff from my scrap-
box. It takes only 3- 4 hours for making and tuning of the antenna.
Flat
EH- Antenna for 10- MHz in the Winter:
By:
Vladimir Kononov, UA1ACO, St.-Petersburg
In three weeks the winter came in my town. I made more
the 100 QSOs with 25 countries using power 30- Wtts. Antenna was covered
by snow but it is worked. I did lots QSOs with the snow- EH-Antenna.
As rule I could make QSO with any station that I heard.
Some
Thoughts on Regenerative Receivers :By:
Paul W. Ross, W3FIS
After having monitored, and occasionally participating,
in the discussions on the Yahoo Regenerative Receiver Newsgroup, I thought
it might be of interest to throw in both some of my experiences, and professional
thoughts. I suffer from being an E.E. by training, having grown up at
the tail end of the vacuum tube era, as well as having held an amateur
radio license for half a century.
Note from va3znw: It was the first tube regenerative receiver
that I have made by myself. At the far times I was a thirteen years old
boy that fall into radio and certainly into amateur radio. I already made
a transistors' then tubes' HF converter for my old tube receiver "Muromets."
So, I could hear amateur stations.
However, one friend of mine, old ham (he was at the times
in his forties) told me about my converters:- "Good job! But.. what
I would like to say all the stuff (converter and receiver) you may
change for one tube receiver. It would get the same reception."
Another day he gave me an old soviet magazine "Radio"
with the schematic. When the receiver was made and tuned, I discovered
that the one- tube receiver really worked almost similar to converter
with "Muromets."
A
Multi Band Tube 10 w QSK Transceiver:Igor
Grigorov, UZ3ZK
In the SPRAT # 67 (SPRAT is the journal of the G- QRP- Club)
was published a circuit of a tube DC receiver. I made this G0ILL receiver
and enjoyed of it perfect reception. Later I modified the receiver to
transceiver.
A
10- meter Band CW Transceiver :Vladimir
Polyakov, RA3AAE
It is a variant of a simple DC transceiver. Transistor of
PA works like a mixer in receiving mode. So, there is no any commutation
in the RF circuits. The transceiver has output power 0.35- Wtts, shift
TX/RX- 400-Hz, RX sensitivity 2 microV. Power voltage is 15-V, current
at RX/TX - 30/120-mA.
An
80 m CW Valve Transceiver :By:
Igor Grigorov, RK3ZK
It is possible to build this transceiver in one evening
using surplus parts. It has a sensitivity of near 5- microV and output
power on 3.5- 3.6- MHz near 1-Wtts.