[TenTec] Keyclicks

[malcolm.mcleman]

Hi all,

       Can anyone tell me how key clicks are produced keying the sidetone oscillator to produce a 800-1000hz lsb output or by unbalancing the balanced modulator to give a similar frequency differential on CW transmit in what are ostensibly SSB rigs with CW add-on as an afterthought?
       Keyclicks were/are generated by keying a relatively high voltage circuit  such as anode, grid block or cathode keying  in valve transmitters of yesteryear. To prevent the almost square wave type hard signal with its inherent key clicks a simple filter across the key contacts in the shape of a capacitor and inductance in series was the norm. The C to prevent the rapid rise time on key down and the L  the fall time on release of the key on key up. Over doing the values of L and C led to what was known as soft keying ie the wave shape was very rounded and difficult to read.
      This is the first time I have take part in CQWW and the reasons for the suspect key clicks for me are numerous but not necessarily generated by the key. Anyone who sponsors a contest with a maximum power of 1500w need their heads looking at
and equally so anyone who wishes to use this type of power to bulldoze their way to victory. Most of the offending signals I heard were from stns using  prime movers with kilowatt afterburners. The rest and lets face it there are still a few about from the eastern bloc who are still using antiquated, with the probability of poor mains, badly regulated equipment. Can I suggest a 100w max output which I am sure will cut down on a lot of the spectrum noise!

73

Malcolm/F5VBU/GM3UIN

NNNN
  
 


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