Central States VHF Society

Exploring the World Above 50MHz since 1965

  • Digital Communications

    A great number of exciting new digital operating modes have developed, largely because of the availability of personal computers, soundcards, and advanced software. But amateur digital communication began in earnest in the late 1940's (if you don't count Morse as a digital mode!) when hams worked out techniques of connecting mechanical Teletype keyboard/printers to amateur gear using FSK and AFSK modulation. WSJT has become a very popular tool for digital communications. FSK441 mode is in use for meteor scatter contacts and JT65 is popular for terrestrial communications.More Info
  • EME Moonbounce

    Amateur radio (ham) operators utilize EME for two-way communications. EME presents significant challenges to amateur operators interested in working weak signal communications. Currently, EME provides the longest communications path any two stations on Earth can utilize for bi-directional communications. Amateur operations use VHF, UHF and microwave frequencies. All amateur frequency bands from 50 MHz to 47 GHz have been used successfully, but most EME communications are on the 2 meter, 70-centimeter, or 23-centimeter bands. Common modulation modes utilized by amateurs are continuous wave with Morse Code, digital (JT65) and when the link budgets allow, voice..More Info
  • Aurora and Solar Weather

    The interaction between Earth's magnetic field and Solar particles is a complex and mysterious field of science. The storm events involve high electric currents in the ionosphere and vast amounts electric power affecting to great many things. One of the ways to observe what is happening up there, is to detect the effects of these phenomena to non ionizing long wave electromagnetic radiation - radio waves.More Info
  • VHF Contesting and Rover Operations

    Hams have been putting stations in their cars since the Twenties (1920's that is). Today, there is great satisfaction in facing the challenge of installing a transceiver in our small cars and pick-ups, using somewhat inefficient antennas, and still being able to make contacts with hams thousands of miles away while "tooling" down the highway.More Info
  • Annual Technical Conference

    Every year since 1968, during the last weekend in July, the Central States VHF Society hosts an annual technical conference. There are two days of technical presentations, antenna range gain measurements, noise figure measurements, a flea market, and often times a vendor area. It's a great time to learn about weak signal VHF communications and an excellent place to network and catch up with old friends.More Info

2005 Antenna Gain Results

Tested in Colorado Springs, CO - July 29, 2005


144 MHz CallDesignGain (dBd)
WB0TEMReference Yagi12.2
N0KM6 ele Quad on 6' boom9.4
WA0VSL3 ele HB yagi6.2
WA9HIR5 ele MASPRO Comm5.8
WA5VJB2 ele "cheap yagi"4.6
W3KHCircular Quad helix- 0.8
222 MHz CallDesignGain (dBd)
WB0TEMReference yagi13.2
WA0VSL4 ele "cheap yagi"7.0
432 MHz CallDesignGain (dBd)
N0KM4 X 22 ele K1FO's
(Range compression due to short range?)
NOKM2 x 22 ele K1FO's Pair 117.9
NOKM2 x 22 ele K1FO's Pair 217.6
AA0L16 ele Com'l Yagi13.7
W6AT9 ele HB Yagi12.2
WA0VSL6 ele HB Yagi9.4
AA0L #16 ele HB Yagi7.2
WD5AGOStudent #1, 7 ele6.4
W0LMD #15 ele HB Yagi5.3
W0LMD #25 ele HB Yagi5.3
AA0L #211 ele HB Yagi4.8
WD5AGOStudent #2, 6 ele4.5
WD5AGOStudent #3, 6 ele4.0
W0LMD6.5t HB Helix2.0
902 MHz CallDesignGain (dBi)
WA5VJBReference Antenna7.5
WA5VJBCom'l 800-1000 MHz LP6.9
WA5VJB4 ele "Cheap Yagi" w/2' RG-586.1
1296 MHz CallDesignGain (dBi)
W7QXHB 39 ele, K1FO design21.4
W6AT22 ele M2 Yagi20.7
WJ0CQuad 1420MHz HydrogenLine Helix, 0.3 axial ratio19.3 (dBiC)
W0LMD22 ele M2 Yagi18.6
VE3ADQ2 Combined 'Cheap Yagis'17.6
VE3ADQ10 ele 'Cheap Yagi #2'14.8
VE3ADQ10 ele 'Cheap Yagi #1'14.6
 Reference Antenna13.5
WA0VSLCom'l corner reflector13.3
2304 MHz CallDesignGain (dBi)
WA5VJBSeavey 28 Patch array for 2.2GHz19.4 (dBiC)
WA5VJBReference Horn12.4
2402 MHz CallDesignGain (dBi)
W0LMD7.5' dish w/'CP' feed #129.1h/24.9v
W0IOGrid dish w/2-11 GHz VJB PCB LP Feed20.0
KO2R18" Offset dish w/5t Helix feed16.2h/2.9v
WA5VJB11 ele "Cheap Yagi"11.7
WA5VJBCircular Brass Patch9.8
W0LMDCP Patch Feed #19.5h/3.6v
WA5VJB6 ele "Cheap Yagi" #29.3
WA5VJBRectangular Brass Patch9.1
WA5VJB6 ele "Cheap Yagi" #18.9
KO2R5t Helix Feed10.2h/2.7v
3456 MHz CallDesignGain (dBi)
N0IOGrid dish w/2-11 GHz VJB PCB LP Feed26.3
KF0QDirective Systems 45 ele Loop Yagi19.4
WA5VJBIONICA Patch Array16.3
WA5VJBReference Horn16.0
N9KC6.4" x 4.9" Horn14.4
5760 MHz CallDesignGain (dBi)
N0IOGrid dish w/2-11 GHz VJB PCB LP Feed24.8
WA5VJBReference Horn19.8
N9KC6.4" x 4.9" Horn15.1
10 GHz CallDesignGain (dBi)
KF0QDirective Systems 60cm dish
Feed:  position 1 / pos'n 2 / factory pos'n
29.7 /29.4 /21.5
WA0VSL12" Com'l Dish27.8
WA5VJBScientific Atlanta Reference Horn23.5
ND2XDual polarity Horn21.1h/19.7v
W7CS4.5"x 3.3"x 7" Horn w/WR90/N adapter20.6
W7CS5"x 5"x 10" Horn20.5
W7CS4.5"x 3.3"x 7" Horn w/HB adapter18.7
WA0VSL2.4"x 4" Horn18.5
W7CS3.2"x 2.5"x 2.5" Horn18.0
W7CSChaparral Style Horn15.0
WA0VSL2.5"x 1" Horn14.5
WA5VJB12 slot WG Ant. (sharp peak - NOT omni)14.0
24 GHz CallDesignGain (dBi)
KM0TFlann Microwave Model 2088KREP-AB
21-23 GHz Horn/Lens
WA5VJBReference Horn19.8
WA5VJBEMS Sectoral Horn 'H' version19.8
WA5VJBEMS Sectoral Horn 'V' version19.8
WA5VJBG3JVL PCB slot array19.8
47 GHz No entries
80 GHz CallDesignGain (dBi)
W5LUA11.5" dish w/Back Splash Feed24.8
WA5VJBMillitech Reference Horn19.8

144 - 432 MHz results in dBd by WB0TEM
902+ results ib dBi by WA5VJB and N0KP

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