From: rc@cmr.ncsl.nist.gov (Robert Carpenter)
Newsgroups: rec.radio.amateur.misc
Subject: Six Meter Question
Date: 21 Jul 1992 17:57:40 -0700
Organization: National Institute of Standards and Technology
	formerly National Bureau of Standards
NNTP-Posting-Host: ucsd.edu

There was a question about 6-m operation in 92-717. Here is a LONG reply:

l---+---L1----+-T--2----T----3--T-+----4T---+---T5----+-T--6----R----7--T-+--r
        This is revised from a message I sent some time ago to 
        someone who enquired about six meters.  Since I just saw 
        another such request, I'm posting it for general 
        information.  Absolutely no endorsements are given, 
        especially no endorsements from my employer.
           ***************************************************
        
        Firstly, six is something of an acquired taste, I 
        suppose.  There is relatively little FM activity on six, 
        and in any case I don't take part in it.  I'm on the low 
        end; the place where SSB/CW activity is concentrated. 
        There is not much local rag-chewing on six. Except as 
        mentioned below, there has been essentially no packet 
        work on six. 

        Most of the SSB/CW operators on six are at least vaguely 
        interested in radio propagation effects.  One of the 
        things that keeps many people on the band is that nearly 
        every propagation mode know to hamdom happens on six at 
        one time or another.  It has held my interest for many 
        years.  Oh sure, I've done some operating on other bands, 
        and have been pretty inactive for a year or so at times, 
        but .... 

                                OPERATION
        
        Operation is mostly on SSB, but switching to CW is common 
        for really weak sigs, and a few people operate nothing 
        else.  Per the FCC, SSB must be above 50.1 MHz.  The DX 
        calling frequency is 50.110 MHz.  The calling frequency 
        when looking for US and VE contacts is 50.125 MHz. The 
        range from 50.100 to 50.125 is kept clear from domestic 
        QSOs, to give the DX stations a chance to be heard. Only 
        on the wildest of Es openings do you find SSB operation 
        much above 50.200 MHz.  The are a few dozen CW (A1 or F1)
        propagation beacons in the 50.060 to 50.080 MHz region in 
        the US, and others elsewhere around the world in the 50.0 
        - 50.1 range (VK/ZL are above 51 or 52 MHz).  As well as 
        signal reports, most stations exchange "grid square" 
        information.  On VHF and up bands, the world has been 
        divided in 1-degree lat x 2-degree long "squares" which 
        start at the south pole and date line and "read right 
        up".  I am in FM19, for example - actually FM19JB, each 
        major "field" (FM) being divided 10x10 into 100 squares 
        (19) and "square" being divided 10x10 into 100 subsquares 
        (JB).  European stations like the subsquares; most US 
        stations don't even know their own.  In any case, the 
        "squares" and their VUCC awards have been a wonderful 
        interest builder, and have kept the QSL printers in 
        business! 
        
                                   RIGS
        
        The equipment situation is easy to cover, so I'll do that 
        first.  Probably 50% of the active stations have 80 to 
        150 W output, either from old Icom 551D s (the 551 is 10 
        W), or from solid-state (brick) amplifiers following the 
        many types of 10 W rigs.  Perhaps 40% of the stations run 
        just 10 to 20 W, but most of them either get an amplifier 
        or drop out after a year or so.  The remaining 10% have 
        either tube rigs such as the Drake TR-6, Swan 250 (too 
        drifty!), Heath SB110A (spurious sig 150 kHz or so from 
        output), or high-power amplifiers.  The kilowatt is quite 
        rare on six (see below for why).  The norm for "serious" 
        stations is the 150 W amplifier.  
                                                  
                                 ANTENNAS
        
        A beam is essentially necessary.  Everyone is 
        horizontally polarized, but cross-polarization doesn't 
        matter for Es, F2, or Aurora. A few stations use 3-
        element beams, but a 4 or 5 element beam is so small that 
        a LOT of people use them. Quite a few people have 
        Cushcraft 6-element "Boomers".  Mine really over-shadows 
        the house!.  There are a few other big beams, and the 
        lunatic fringe stacks them, etc. For example, K6QXY 
        showed me a photo of his stack of 4 six-meter beams, 
        each with a 50ft (15m) boom. The higher the tower the 
        better!  RG8 or RG213 is plenty good enough cable for 
        most people.  Antenna-mounted preamps are never needed.  
        External noise is fairly high at 50 MHz.  It overrides 
        the front-end noise figure on about all the rigs on the 
        market today unless you have a LOT of cable loss or a 
        VERY quiet location. 

                              PROPAGATION

        Tropo - The ordinary ground-wave tropo range on six isn't 
        quite as great as on two.  There are a number of reasons.  
        Since there are so many other prop modes on six, people 
        don't try so hard on tropo.  Antenna gain often is higher 
        on two.  Noise is lower on two.  At least in the summer, 
        stations like W3BWU (Pittsburgh), W3IDZ (northern NJ) are 
        easily worked from here with the beam pointing at them, 
        and can be heard at almost any pointing.  They are in the 
        150-W class. 

        Meteors - Any area workable by meteors can be worked more 
        easily by Es or aurora. Even though meteor bursts are much 
        strong and longer on six than on two, little use has been 
        made of them.  There has been a VERY little meteor-burst 
        packet work on six.  I had the first such contact (with 
        W0RPK). W3XO worked him a few years later. 

        Ionoscatter - Some people think it's really meteors, but 
        every weekend morning there are a number of nearly-
        kilowatt stations working each other on SSB at distances 
        of about 600 - 1000 miles by ionosperic scatter.  Sigs 
        are weak, and it takes good beams, height, and power, but 
        it is very reliable.  See the old NBS papers by Bailey, 
        Bateman and Kirby, et al.  Bateman and Kirby were/are 
        hams.  Ross Bateman died last year.  Dick Kirby continues 
        as head of ITU in Geneva. 

        Aurora - Much easier than on two.  SSB is usually 
        intelligible.  Point north about dusk, most commonly in 
        March and October/November.  Lots of people work this 
        mode when it happens. 

        Es - You know something about Sporadic E (Es) from TV.  
        When you see interference bars on channels 2, 3,..,6, 
        there is Es DX on six. Having much better antennas, 
        modulation, and receivers, hams work Es when it isn't 
        strong enough to be noticed on the TV. Es is most common 
        from May to August, and around Christmas, here in 
        Northern latitudes. In addition to the common single-hop 
        range of 500 - 1500 miles, there are quite a few double-
        and-more hop contacts on six.  Now that a number of 
        Europeans are on six, we find that they can be worked 
        from the US east coast each summer.  Likewise the 
        Caribbean stations work all over the US.  The US west 
        coast has an easy time with Hawaii and Alaska. 

        F2 - This is the traditional world-wide F-layer 
        propagation you know and love from 20 and 15 meters.  At 
        most sunspot maximum periods, a few years of each eleven, 
        the MUF reaches above 50 MHz in the autumn and spring.  
        It isn't every day, but even antipodal communication has 
        happened.  Some dozens of stations now have cards from 
        100 countries.  But they have spent MANY hours over many 
        years trying to catch the fleeting opening.  F2 brings an 
        influx of the lower-band DX operators.  The normal rather 
        gentle operation gets somewhat lost at those times. 

        Transequatorial Propagation - The southern US gets a 
        number of openings to South America by some kind of 
        ionosphericaly-ducted propagation.  The stations are 
        generally about equidistant either side of the magnetic 
        equator.  Given exceptional luck, an Es opening linked 
        into this mode can make it available to more northern 
        stations.  This mode has bad flutter fading and a touch 
        of the auroral spectrum spreading.  This mode also works 
        sometimes on two meters if you use CW and really good 
        gear.  It has been worked on 432 MHz. 

        EME - There have been a few EME contacts on six, but the 
        required antenna size and high background noise makes it 
        out of the reach of most people.
        
        Did I leave any modes out?

                                 TVI, ITV

        There is no doubt about it, six has TVI troubles.  You 
        don't find a lot of people on six in channel 2 areas 
        unless cable is widely subscribed-to.  VCRs are very 
        prone to six-meter pickup.  The common connecting or 
        power cable is a quarter-wave antenna for six ....  The 
        TV owners have their revenge since the 13th harmonic of 
        the color subcarrier, or something, of TV sets and TV 
        games puts out a birdy at 50.113 MHz to bother the six-
        meter operators in return....  There is also quite a bit 
        of trouble from noisy power distribution lines if they 
        aren't buried (usually bad insulators or poor guy 
        bonding). 

        73,
        Bob W3OTC