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

2010 Antenna Gain Results

Tested in St Louis, MO - July 23, 2010

 

144 MHz CallDesignGain (dBd)
WB0TEMRef Ant (11 El K1FO)12.2
AB0RX11 element HB11.4
N0OBI3 element HB5.7
WA5VJB19 El 432MHz K2RIW-0.6
WA5VJB13 El 220MHz WB0TEM>-20
 
222 MHz CallDesignGain (dBd)
AB0RX15 element HB14.4
WB0TEMRef Ant 13 El WB0TEM13.2
K5VHK5VH Superwheel5.2
WA5VJB11 El 144 MHz K1FO-3 @ 30°
WA5VJB19 El 432MHz K2RIW-6.8
 
432 MHz CallDesignGain (dBd)
WA0ARMstacked pair 15 El W0EYE16.4
WB0TEMRef Ant 19 El K2RIW14.8
K0CQ19 El K2RIW-derived #214.2
K0CQ19 El K2RIW-derived #1 taped14.0
WA0ARM15 El W0EYE (bottom of stacked pr)13.9
WA9KRT23 element VE7BQH13.8
WA0ARM15 El W0EYE (top of stacked pr)13.7
AB0RX23 element HB Yagi13.6
N0XPM-Squared 440-1813.6
N0OBI7 element HB Yagi12.2
KD4NOQ10 elelment cross Yagi12.2
K4QF10 elelment HB Yagi10.7
W0FMC5 element Arrow Yagi9.3
N0RWW6 element ATV Yagi7.0
K5VHK5VH Superwheel4.4
WA5VJB11 El 144 MHz K1FO0.8
K5VHHalo0.3
K5VHSqualo-2.7
WA5VJB13 El 220MHz WB0TEM-9 @ 45°
 
902 MHz CallDesignGain (dBi)
WA0CNS21 element F9FT rebuild15.8
NG9R10 element cheap Yagi13.4
KD4NOQ9 element cheap Yagi12.6
KA2KQM11 El Sinclare 3Y415-SLXSMN9.7
WA5VJBReference Horn9.0
KD4NOQPopcorn Can Horn8.9
WA5VJBLHCP cavity-backed spiral dBic3.0
WA5VJBRHCP cavity-backed spiral dBic2.2
WB0DBSBicone omni>-10
 
1296 MHz CallDesignGain (dBi)
AF4JF55 element loop Yagi20.8
AB0RX45 element loop Yagi19.2
WA0CNS28 element loop Yagi17.8
W0FMS20 element Yagi16.7
WA5VJBReference Horn12.2
KD4NOQHB 432/1296 Yagi8.0
K5VHAlford Slot6.8
WA5VJBRHCP cavity-backed spiral dBic 1.5dB Axial ratio1.2
WA5VJBMilitary 4" dia conical spiral 3.2 dBic0.2
AB0RXCom'l Yagi (not functional)>-10
 
2304 MHz CallDesignGain (dBi)
KO0Z4' offset dish VJB LP feed (range a bit short for this gain)29.7
WA5VJBReference Horn12.5
KD4NOQ1 lb Coffee Can5.0
KD4NOQChocolate Can5.0
KD4NOQHB Double Diamond4.5
WB0DBSOmni sector horn Bicone3.0
 
3456 MHz CallDesignGain (dBi)
KO0Z4' offset dish VJB LP feed (range short for this gain)30.5
W0FMSPatch Antenna7.5
KD4NOQCantenna Horn7.0
KD4NOQDouble Diamond ove jar lid<0
 
5760 MHz CallDesignGain (dBi)
KO0Z4' offset dish VJB LP feed (range short for this gain)30.5
W9SZ2' dish with RMX PCB feed23.6
WA5VJBReference Horn22.1
WA5VJB16 element Patch array #117.2
WA5VJB16 element Patch array #2 (optimized 5.9-6.0GHz)15.3
 
10 GHz CallDesignGain (dBi)
K0MHCChannel Master offset dish (range short for this gain)44.9
W0FMS24" offset w/W1GHZ feed #134.0
K0MHC22" Directive Sys dish w/Dir. Sys feed33.7
KO0Z4' offset dish VJB LP feed (feed focus not adjustable)32.3
K4QF18" Direct TV dish w/W1GHZ feed33.7
W0FMS18" offset diah w horn feed31.5
W9SZ2' dish w/splash feed closer to dish30.5
W9SZ2' dish with splash feed29.0
N0OBI18" Direct TV dish w/Cu H2O pipe feed & WG28.5
WA5VJBReference Horn 3.5 x 3 x 323.5
WB0DBSDual ridged waveguide feed Port 19.4
WB0DBSDual ridged waveguide feed Port 28.3
WB0DBSDual ridged waveguide feed Port 2<0
 
24.1 GHz CallDesignGain (dBi)
WA2VOI13" dish w/Cassigrain feed33.7
W0AUSHorn 7.6 x 10.5 x 22.7 cm24.9
W0AUSHorn 6.3 x 8.9 x 13.8 cm23.3
WA5VJBReference Horn20.7
W0AUSHorn 4.3 x 5.8 x 6.7 cm20.5
WB5LJCReference Horn 3.4 x 4.3 x 4 cm18.4


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