[UK-CONTEST] Keyboard delays

[Ian White GM3SEK]

Chris Tran ZL1CT wrote:
>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)

Under 2ms is easily achievable by kicking the relay with a 
double-voltage pulse, falling back to normal voltage to hold in. That 
means the whole amplifier can be ready in 3-4ms, which is plenty of time 
for any modern transceiver that has a delay of about 10ms.

That is, IF the transceiver and amp are correctly configured to work 
together (see below).

A new sequencer has just appeared on the market, that not only does the 
usual TX/RX delays but also delays the whole data stream from the keyer, 
so that even the first dot is complete. (The delay is said to be too 
short to interfere with manual sending.)
http://netcertus.com/cgi-bin/netc/net.cgi?page=ampsequencer

The reference to "G3SEK" on that site is not a product endorsement, but 
leads to an old posting to the AMPS reflector which sums up the general 
RX/TX timing problem at greater length. You can also click through to 
the full-length version that formed the basis for my talk to the HF 
convention about 3 years  ago, which was mostly about configuring the 
transceiver and amplifier to work together.


-- 
73 from Ian G(M)3SEK