[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
 =20
=20


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