ham radio: Antennas

[last updated: 2024-03-08]
ham radio home page
ham equipment
vertical antenna with loading coil
antenna volts and amps

(link to:) coax specs
-----

This page is rough and in development...
-------------------------

On This Page:
- Antenna Theory:
- Dipole Antennas:
  Fan dipoles
  EDZ
  End-fed antennas
  G5RV
  also search for: caged dipole
- Yagi Antennas (a type of dipole):
  Calculator
  Hexbeams
  my DIY 70cm
- Vertical Antennas (a type of dipole):
  Hamsticks
  Slim Jim
  Mag-mounts
  ... others
- Loop Antennas:
  Magnetic loop
  Tak-tennas (Petlowany)
  Delta-loop project
- Other Antenna Types:
  turnstile antennas
  earth-probe antennas
  isotron antennas
  gotham antenna
  quagi antennas: http://www.overbeck.com/quagi.htm
  quadrifiler
- Other Components:
  Baluns (& toroids):
  coax
  Arduino EMF detector
  rPi RF detector board
- Resources/Links:
  (link to:) HamUniverse DIY antenna projects:
========================================
Antenna Theory:

----------

Dipole antennas:
- Standard dipole:
  Normally total length is 1/2 wavelength.
  Nominal impedance is 72 (or 73) ohms.
- Fan dipole:
- EDZ: Extended Double Zepp:
  - The version SteveS built for April is 175' long, with a 9:1 balun feeding into 450-ohm ladder line
    This total length calculates to resonate at 7 MHz.
  - Basics:
    EDZ are dipoles
    Using larger diameter wire gives more bandwidth
    Each leg of the dipole is cut to be 5/8 wavelength of your target frequency.
    Connect a 450-ohm ladder line to the dipole legs
    The ladder line is the "stub" with specific length:
    Install a current balun at the end of the stub to connect to 50-ohm coax to the transmitter. Online suggests a 4:1 balun.
    The balun should be rated at twice the intended output power (due to inherent impedance mismatch of this non-resonant antenna design?)
  - This link:
    http://www.westmountainradio.com/antenna_calculator_zepp.php?frequency=7.1
    has a calculator.
    It says to use a 4:1 balun.
    It further says that a "Ground Reflector can be added to enhance NVIS Propagation at frequencies below 10 MHz"
    A lot of options are given for ground reflector material and configuration.
  - Other links:
    http://www.iw5edi.com/technical-articles/building-a-double-extended-zepp...
    EDZ: http://www.antentop.org/w4rnl.001/mu3a.html
    EDZ: http://www.zs6wr.co.za/antennas/zepp0001.pdf
    https://w5zotexas.blogspot.com/p/extended-double-zepp-new-look.html
    Yagi calculator: https://www.changpuak.ch/electronics/yagi_uda_antenna_DL6WU.php
    Dx Zone - antenna calculator links: https://www.dxzone.com/catalog/Antennas/Antenna_Calculators/
- End-fed antennas:
  - EF-10/20/40 Mk2: LnR Precision Inc - 25w max
    30+ ft long
  - EFHW-8010-1k: MyAntennas.com, end-fed half wave for 80M - 10M
    ~ 130' long
- Search also for: ZS6BKW / G5RV Optimized Multi Band HF Dipole Antenna
- Search also for: W5DXP Multi-band Dipole Antenna
----------
Yagi antennas:
- Yagi's have a dipole "driven element", a "reflector" element behind it, and one or more "director" elements in front of it.
  While the dipole element has an impedance of 72 ohms, the other nearby elements reduce the net feedpoint impedance.
  Net impedance can be as low as 10 ohms.
- (link to:) RF Wireless World Antenna Calculator
- Wire beams (hexbeams, umbrella antennas): (link to:) karinya.net
- my DIY 70cm Yagi
- Search also for: Arrow-II foldable yagi antennas...
- https://jeroen.steeman.org/Antenna/Yagi-Antenna-Calculator
  http://www.mapleleafcom.com/calculator_3element_yagi.shtml
  https://3g-aerial.biz/en/online-calculations/antenna-calculations/dl6wu-...
  https://www.wireantennas.co.uk/yagi-antenna-calculator
  http://pencho.my.contact.bg/start/comp/anteni/Yagi.htm
----------
Vertical antennas:
- Hamsticks:
  - 9120 20M hamstick: labeled: "Lakeview Co Inc" with address & partial ph# in So Carolina
    PO reported it's tuned to 14.320 MHz
    with a 3/8-24 male thread base
  - 80M hamstick: labeled: "75M HF Mobile Antenna"
    PO reported it's tuned to 3.950 MHz
    with a 3/8-24 male thread base
- (link to:) Slim Jim portable antenna 2m & 70cm $23
- (link to:) CG220 4' 9" long, $44, 80m
- 2m - 70cm Mag Mounts:
----------
Loop antennas:
- Magnetic Loop Antennas:
  - (link to:) Hackaday
  - Search for: Comet-CVBA-500BC-5-BEA-L-Vacuum-Capacitor
  - (link to:) project with stepper-driven tuning
  - (link to:) antenna dimension calculator
  - (link to:) alexLoop
  - Tak-tennas (Petlowany):
  - Butterfly capacitors:
  - (link to:) ...at DigiKey/">(link to:) build a delta-loop antenna
  ----------
- Other Antenna Types:
  - (link to) Turnstile antenna - wiki
  - Search also for: Steppir Antennas...
  - earth-probe antennas:
    (link to:) earthProbes
    (link to:) rtl-sdr.com
- Other Components:
  - Baluns (& toroids):
  - Coax:
    For HF, LMR-400 is arguably one of the best coax types to use.
    For UHF/VHF, RG-58 or RG-8X are sufficient (and cheaper)
    (link to:) coax specs
  - (link to:) Arduino EMF detector
    https://projecthub.arduino.cc/TruePatrick/71308fec-9cf5-4346-8a8f-ef20d0...
  - (link to:) Mikroe-2034 RF meter (board for rPi...at DigiKey)
  - (link to:) Mikroe RF Meter (SPI connect to rPi or Arduino)
- Resources/Links:
  (link to:) HamUniverse DIY antenna projects
  ---------------------------------------------------------------------
  #############################################################
.

.

.

eof

Main Menu

Main menu

Site Menu

You are here