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

1999 Noise Figure (NF) Results

Tested in Cedar Rapids, IA - 24 July 1999

 

50 MHzCallDesignDeviceNF (dB)Gain (dB)
N0AKCDEMI 0.5618.7
WA5VJBWA5VJBMGF18010.1621.9
N0AKCWA5VJB DEADDEAD
 
144 MHzCallDesignDeviceNF (dB)Gain (dB)
KA0RJTKA0RJTFSC11LF0.1125.67
JH7SIAJH7SIA 0.1125.53
JH7SIAJH7SIA 0.1525.25
WA5VJBWA5VJBMGF18010.1516.89
WA5VJBWA5VJBMGF18010.218.15
WA5VJBWA5VJBMGF18010.4416.7
W0PTARR SP144VDG 0.5223.37
N0UKCSVHFS PROCEEDINGSMGF-13020.6923.09
W0PTARR SP144VDG 0.8622.56
WA5VJB Stacked 1302's114.3
N0UKHANDBOOKDG MOSFET NTE4541.3325.7
N0UKDEMIATF 101362.420
 
222 MHzCallDesignDeviceNF (dB)Gain (dB)
N0UKHANDBOOKNTE45449.8
N0AKCM.C.M.MGF1302DEADDEAD
 
432 MHzCallDesignDeviceNF (dB)Gain (dB)
KA0RYTKA0RYTNE334501DEADDEAD
KA0RYTKA0RYTATF101360.1527.83
KA0RYTKA0RYTATF101360.1625.67
KA0RYTKA0RYTNE325840.1923.03
KA0RYTKA0RYTNE332840.2123.36
JH4JLVJH4JLVNE3295010.2424.22
W7QXW7QX-2 STAGENE334/ATF101360.2639.45
KA0RYTKA0RYTATF341430.2720.48
JH4JLVJH4JLVNE3295010.2720.82
JH0WJFJH0WJF #2MGF14020.317.72
JH0WJFJH0WJF #1FHX35LG0.324.23
KA0RYTKA0RYTATF101360.3227.18
VE6TAM.C.M.MGF13020.3419.75
VE6TAM.C.M.MGF13020.4218.44
AL7EBN9MKC 0.8520
AL7EBDEMI 1.1912.84
N0UKDEMIATF101361.5713.51
WA5VJBMirage KP-1/440 2.0716.6
WA5VJBRDIAT415 NPN2.559.72
 
903 MHzCallDesignDeviceNF (dB)Gain (dB)
N0AKCDEMI 0.5221.37
W9FZDEMIATF101361.448.2
N0AKCMCMMGF13021.949.4
N0AKCCELLWAVE 3.3719.67
 
1296 MHzCallDesignDeviceNF (dB)Gain (dB)
W7QXW7CNKNE3340.2223.03
W7CNK  0.2219.53
W7CNK  0.2218.43
KA0RYTKB2AUNE3345010.2820.18
KA0RYTKB2AUNE3345010.3215.22
W7QXW7QX 2 STAGENE334/ATF101360.4630.14
W7QXW7QX 2 STAGENE334/ATF101360.5728.57
W7QXW7QX 2 STAGEFHX05/ATF101360.630.51
VE6TAWD5AGO 0.6814.14
K9EK1/2 WAVE CAVITYMGF13020.7610.63
N0UKDEM101360.814.31
K9EK1/4 WAVE CAVITYMGF13020.8214.69
AL7EBN9MKC 1.1912.84
 
2304 MHzCallDesignDeviceNF (dB)Gain (dB)
WA9FNDDEMI 0.4617.95
K9EKW5LUA 0.5216.74
WA5VJBDJ6BVNE326840.6513.96
WA5VJBDEMI 0.8314.96
 
3456 MHzCallDesignDeviceNF (dB)Gain (dB)
W9FZW5LUAATF101361.0925.96
KD4NOQ  5.889.27
 
5760 MHzCallDesignDeviceNF (dB)Gain (dB)
WA9FWDDEMI 1.1911.73
KD4NDQ  DEADDEAD
 
10368 MHzCallDesignDeviceNF (dB)Gain (dB)
N2CEIDEM-10368-144 Trans 1.7416
 
24192 MHzCallDesignDeviceNF (dB)Gain (dB)
W5LUAW5LUA 2 stage, WG inputHp Indium Phosphide1.9817.6
VE4MA2 Stage, WG inputATF 360772.4213.1
VE4MA3 Stage DB6NT, WG inputNE 3292.7524.5
W5LUAMMIC, SMA In/OutHMMIC-50232.9320.2
W5LUA2 Stage, SMA In/OutATF-360773.313
W0EOMCommercial, 23 GHz 3.5220.6
W0AUSCommercial, 23 GHz 3.9415.5
VE4MAJE1AAHNE 2393.8922
W5LUACommercial, 23 GHz 3.8419.3

Tested by W0PPF,KA0YSQ, W0FMS,W5LUA, KA0RYT,W7CNK
HP346A Noise Source, Measurement Accuracy of system according to HP is +/- 0.2 dB!

Note - HP346C Noise Source used on 24 GHz


Go to top