[UK-CONTEST] Keyboard delays

[Chris Tran ZL1CT]

Hello all

An interesting discussion following on from the Keyboard or Paddle
discussion. I think we would all agree that the operating requirements for
an RSGB CC contest differ considerably from major international contests.
I'm sure that *all* the operators who achieve a top-10 score are using the
keyboard for logging + sending, with possibly the paddle for 'fills' or a
panic correction as discussed earlier. This leaves the operator a few
seconds free to listen on a second radio, write down a partial call heard in
the pile-up, stare at optimistic propagation predictions, whatever....

I would caution against assuming that a station that is slow to respond to a
call is slow because of keyboarding delays - who knows what else the
operator is doing in that 1-1.5s delay ?  I know it's annoying for the
station calling, but you must consider how big the pile-up is at the
responding station's end, whether they are SO2R, etc...

One thing that has not been mentioned too much is T/R timing. My friend Wil
ZL2BSJ recently constructed a sequencer (which was used at ZL6QH in WPX
CW) - there are 2 inputs : one from the paddle/keyer and one from the PC LPT
or COM keying line, and 2 outputs : one to the transceiver PTT and one to
the amplifier control line. These are sequenced to achieve fast T/R times
but without any possibility of 'hot switching' the amp. We are still
debating how fast an amplifier can be fully on-line delivering RF, but the
Emtron DX2 claims a RX to TX time of 2ms. I've never seen a vacuum relay c/o
time better than about 6ms including contact settling time, but Emtron claim
that by having the relay powered up on RX and removing the power on TX they
can achieve the shorter time. (presumably TX to RX takes longer)

Just a personal view, but I've never seen any advantage in the use of QSK,
especially at QRO stations running at high rates - it takes about 2.6s to
send 'CQ ZL1V' at 32wpm, including T/R times. I would rather do something
else in the 2.6s than trying to listen on that radio and also wear out the
amplifier relays !

73
Chris
ZL1CT
(ZL1V in IARU 2005)

P.S. If you are interested in vintage transceivers, please look at my
webpage : www.qsl.net/gm3woj/transceivers.htm