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

1997 Antenna Gain Results

Tested in Hot Springs, Arkansas - July 25, 1997


144 MHz CallDesignGain (dBd)
KBØHH11 el 20 ft boom13
W5UC8 el 12 ft boom11
K5LLLmodified Cush Craft 4 el8
WA5VJBlog periodic8
N9LHD3 el 3 ft boom Swiech COY2M3EL8
WBØTEMreference yagi9.8
222 MHz CallDesignGain (dBd)
WA5VJBlog periodic7
WBØTEMreference yagi13.3
432 MHz CallDesignGain (dBd)
WØDQYJ beam 88 el15
KD4NOQMosley 14 el 5 ft boom11
WA5VJBlog periodic8
N4MWM Squared 432 Sqloop2
WBØTEMreference yagi15.2
902 MHz CallDesignGain (dBi)
K5LLL"4 ft grid dish, dipole feed"16.4
K5LLL12 el yagi13.5
WA5VJB10 el Cushcraft12.6
WB5AOH#1 12 el yagi11.3
WØZQ10 el yagi11.2
WB5AOH#2 12 el yagi10.8
W6OAL11 turn helix9.3 dBic
WA5VJB4 el yagi7.5
915 MHz CallDesignGain (dBi)
WB5AOH#1 12 el yagi for spread spectrum packet11.9
WA5VJB10 el Cush Craft yagi11.7
WB5AOH#2 12 el yagi for spread spectrum packet11.7
W6OAL11 turn helix9.1 dBic
WA5VJB4 el yagi7.5
1296 MHz CallDesignGain (dBi)
K5LLLDEM 24 el loop yagi19.5
KGØMW25 el loop yagi18.5
WVØK24 el (1270 MHz) loop yagi18.5
N5EM20 el yagi (1255 MHz)16.3
W6OAL11 turn helix14.7 dBic
WA5TKUEEMCO #31158.4
WØAUSTriple coffee can8.5
WA5VJB10 el yagi12.5
2304 MHz CallDesignGain (dBi)
K1WHS52 el DEM 1352LY22.1
KØGCJ"25 in dish, log helix feed"20.2
KGØMW"25 in dish, RMX feed"17.2
W6OAL15 turn helix15.6 dBic
WA5TKUEEMCO #31158.8
WØAUSdouble coffee cans7.2
WA5VJBWatkins-Johnson A61006.3
DJ9HOdish feed6.2
WA5VJBNarda reference horn13.4
3456 MHz CallDesignGain (dBi)
WØAUS14 turn helix19.5 dBic
KØGCJ25 in dish log helix19.1 dBic
WØAUS5.5X4.25X12 in horn13.0
WA5TKUEEMCO #311511.0
WA5VJBWatkins-Johnson A61009.2
WA5VJBNarda reference horn16.8
5760 MHz CallDesignGain (dBi)
WB5LUA17.5X11X19 in horn20.4
W5ZN5.5X4X5 in horn17.3
KØGCJ"25 in dish, log helix feed"14.5 dBic
WA5VJBWatkins-Johnson A610013.3
WØAUSflared horn12.9
WA5TKUEEMCO #311511.0
WA5VJBreference horn15.5
10368 MHz CallDesignGain (dBi)
WA8WZG15 in dish/AT 68UP feed27.7
WA5VJBSAR planar slot array20.5
KØGCJ"25 in dish, log helix feed"19.7
WB8IFMAT68UP & Poly Rod16.9
WA5VJBWatkins-Johnson A610015.2
KA8EDE7 in Poly Rod13.2
WA5TKUEEMCO #311513.0
WØAUSsingle flared horn12.7
KA8EDE4 in Poly Rod11.9
WØUC"18 in dish, WG dual dipole feed"11.2
WA5VJBreference horn17.7
24192 MHz CallDesignGain (dBi)
WA5VJBreference horn20.8

Measurements were made on the 902-24GHz were made by WA5VJB.

Measurements were made on the 144 MHz - 432 MHz by WB0ETM

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