[SixClub] Low-Cost Antennas & Other Projects

[Steven Coles]

All,

DXers Unlimited Ask Arnie Index August 2007-December 2007

Professor Arnaldo “Arnie” Coro, CO2KK, provides twice weekly SWL
(shortwave listener) and amateur radio information suited to beginning
through medium radio builders.

You can email Professor Coro at

arnie at rhc.cu

Transcripts can be downloaded from

http://www.radiohc.cu/ingles/dxers/dxersmenu2007.htm

(Recent)

http://groups.yahoo.com/group/regenrx/

(August 2007 to present--posted on the forum)

http://www.dxers-unlimited.dxer.info/

(2003 through 2007) and

http://www.radiohc.org/Distributions/arnie.html

(January through May 2002)


May 8, 2007: TTFD (tilted terminated folded dipole a. k. a. squashed
rhombic antenna), Fan Broadband dipole.


August 21, 2007: radio powered by radio waves, equinoctial propagation,
connecting an RF power amplifier to a an amateur radio transceiver.


August 25, 2007: Fan Broadband dipole, Japanese freeware MMANA antenna
modeling software, radio experiments with the parts recycled from
discarded compact fluorescent light bulbs, loading coils for dipole
antennas, DX tips.


August 28, 2007: Balloon bore repeater, universal linear power supply,
buying broken radios, human-powered radios.


September 1, 2007: AM modulation, regenerative receivers, 12-volt
vacuum-tube cascode regenerative receiver.


September 8 - 9 2007: Log-periodic antennas, a computer mouse as a
telegraph key, micropower DX, selecting headphones.


September 13, 2007: KK-COMP antenna, buying non-operating receives.


September 15, 2007: Crank Powered Radios; Osvaldo Victores, CO3OV,
short-boom, 3-element 2-meter Yagi beam antenna; using discarded
notebook batteries for radios.


September 18, 2007: Tunipole (Grounded Folded Monopole) antenna, using
salvaged cellular telephone microphone elements for ham radio, turning
on old radios slowly, using a small loudspeaker as a mechanical CW
filter.


September 22-23, 2007: Cross coupled regenerative detector circuit in a
Wheatstone bridge balanced configuration, switch-mode power supplies,
and 2-meter FM antennas.


September 25-26, 2007: Simple single conversion superheterodyne
receivers, with a 455 kHz intermediate frequency receive an “image” of a
strong signal 910 kilohertz from the dial frequency, warning against
using banana plugs at radio frequencies, protecting equipment by adding
Transorbs or Peak Suppressors, inexpensive used 2-meter FM transceivers,
minimum HF power required depends on skill level.


September 29-30, 2007: Preparing for emergency communications: 1.
Periodically-tested storage batteries, 2. Prepare reserve indoor
antennas, 3. Protect all antenna connections to the coaxial cable
downleads. Four-Ls antenna, 


October 2, 2007: Wheatstone-bridge regenerative receiver, vertical with
elevated radials (elevated ground plane) antenna, amateur radio
satellites.


October 6, 2007: Amateur radio astronomy (sun & Jupiter), Moxon
antennas.


October 13, 2007: Half square vertical antennas.


October 16-17, 2007: Design criteria for an optimized homebrew receiver,
using the lowest parts count that is still consistent with good overall
performance. Two prototypes provide reception from 500 kHz through 50
MHz. Prototype 1 is all solid state and prototype 2 is a
transistor-vacuum-tube hybrid. Double spiral loaded dipole antennas.
Spiral top loading adds both capacitive and inductive loading to a
vertical antenna. Petlowany and TAK antennas. All spiral-loaded antennas
support only narrow-band operation. RF noise from electric motors.



October 20-21, 2007: Computer crystals for crystal filters and local
oscillators, frequency response of a bandpass filter for AM reception,
and using asymmetrical pulse charging to revive NiCd batteries.


October 23, 2007: Fan type counterpoise antennas, green LED crystal set,
direct conversion, synchrodyne, and homodyne receives.


October 27-28, 2007: Green and Blue LED product demodulators, magnetic
loop antenna for nulling noise.


November 3-4, 2007: The fan dipole (a three-in-one) antenna, disc-cone
broad-band VHF omni directional antenna, Quatrro (4-diode) crystal radio
receiver diagram offered, log periodic road-band VHF beam antenna.


November 13-14, 2007: W6EL propagation forecasting program, LINUX FLDigi
software for Olivia, RTTY and PSK31, problem with the G5RV multiband
antenna resolved.


November 17-18, 2007: 1.4 to 1.7 AM BCB reception as an indicator of
160-meter (1.8 – 2.0 MHz) DX reception, 2-meter band (144-148 MHz)
Super-J antenna, using a BFO to listen to 40-meter CW (radiotelegraph)
and SSB (single side band suppressed carrier).


November 24-25, 2007: Super-J 2-meter band antenna, VHF log periodic
antennas for apartment dwellers, Linux propagation forecasting software
on runs on 486 computers, selecting a band to monitor, selecting
antennas for a farm.


November 27-28, 2007: Micro Vert, Bobtail, and Half Square antennas,
Cuban radio network upgrades.


December 22-23, 2007: The Molnya amateur radio satellite, frequency
converters to extend receive range into the upper HF and VHF ranges,
using an antenna tuner with a Fan Dipole, Cubical Quad beam antenna for
the 2-meter (144-148 MHz) band.


January 5-6, 2008: NVIS propagation mode using low height half wave
dipole and full wave loop wire antennas. (NVIS stands for „Near Vertical
Incidence Skywave“ and produces communniations over a 0 to ~700 km
radius using 10 to 100 W on 40 meters during local daytime and 80 meters
at night), low-cost amateur radio equipment for 40 and 20 meters and an
offer to email daigrams for the low-cost station's bandpass input
filter, RF attenuator and the transmit receive switching.