6, Mounthurst Road,
                                       Hayes,
                                       Bromley,
                                       Kent BR2 7QN
                                       England.
                                       Tel. +44 (0)181 462 4223
                                       E-Mail - memmer@stcssl.co.uk
    Dear Robot 1200c user,
         You may be interested to learn that there is now a new V4.6 Upgrade
    EPROM for the 1200c which has a new HQ mode, which is the culmination of
    many years of experimenting and looking at improving the way SSTV is
    transmitted.
         The main advantage of the new HQ modes is a much sharper image
    than is possible with the current Martin 1/ Scottie 1 modes but in a
    considerably reduced transmission time of just 90 seconds for HQ 1.
         However there is one small disadvantage with using HQ 1, which is
    that it is slightly more prone to noise than the longer modes. This is easy to
    understand if you consider the effect of a one second burst of noise on 90
    second mode when compared to the effect of the same noise pulse on the
    114 second Martin 1 mode, it will obviously be less.
         In practice the new HQ 1 mode will nearly always give a better quality
    picture than either M1 or S1, but in just 90 seconds a saving of some 24
    seconds. For those occasions when signals are marginal and noisy the HQ 2
    (112 sec.)  mode retains the much sharper picture advantage of HQ 1, whilst
    being no longer in transmission time than the M1/S1 modes. It is also possible
    to disable the picture sharpening feature if received pictures seem a little
    noisy.
         Although I am not claiming that the new HQ modes are the "Ultimate"
    SSTV modes, I believe they mark a significant improvement in the art of Slow
    Scan Television, such that the HQ modes will probably become the future
    SSTV modes of choice and details will be made available to other systems
    which are capable of conforming to the precise timing requirements of the HQ
    modes.
         The V4.6 EPROM is now available at a special  introductory price of 
    $50, until the end of 1996  when the price will increase to $70. This is to
    encourage as many as possible to start using the new HQ mode.
         The price includes the return of your old EPROM (V4.0 or later). You
    do not need to return the old EPROM until you have the V4.6 EPROM
    installed and are satisfied that it is working correctly.
         If you do not want to return your old EPROM, just add $20 and I will
    provide a new EPROM, if you subsequently return your old EPROM I will give
    you $20 credit towards the next upgrade.
         If you have any questions, comments or would just like some
    additional information on the new V4.6 EPROM or the HQ mode or any other
    features, please feel free to contact me at the above address.
         If you would like an unbiased opinion of the HQ mode, just log onto
    Bob G0AZX (an existing V4.6 EPROM user) web page:-
    http://members.aol.com/jpritch638/sstv/martin2.htm
         If you do not have internet access just get in contact and I will send a
    print out.
                          Best 73's
    
    
                        Martin G3OQD