TXDELAY

Command

TXDELAY -- Display / Set the transmit keyup delay for a port.

Synopsis

TXD[ELAY] <port> [millisecs]

Availability

Sysop-only.

Description

The TXDELAY command allows the value of the transmit keyup delay for a port to be displayed or altered. This is the interval between the transmitter being keyed up and the start of a transmitted packet. (see NOTES).

Any changes made by this command override the settings specified in the PORT sections of XROUTER.CFG, and remain in force only until XRPi restarts.

Options

If a single numeric argument is supplied, the current value for that port number is displayed.

If two numeric arguments are supplied, the first specifies the port number, and the second specifies the new value for the parameter in milliseconds.

Examples

TXDELAY 3       - Display current setting for port 3
TXDELAY 3 300   - Set port 3 txdelay to 300 millisecs

Notes

TXDELAY is the interval between the transmitter being keyed up and the start of a transmitted packet. It allows time for the RF to reach its full value, and for the TX audio circuits to stabilise. Some synthesised rigs require a large txdelay (500 or more) to allow the synthesiser to swing between RX and TX frequencies, and many rigs have audio stages which take 100 ms to stabilise while oversized electrolytics charge up.

One factor which is often overlooked is the other end's receiver. It takes a finite time for the squelch to open, and if the rig has just been transmitting it may take a while to stabilise back to receiving, especially with synthesised rigs. If your txd is too short, you will be sending replies before the other end is ready to hear you, and unnecessary retries will result.

On KISS TNC's, you should allow up to 5 minutes for any new setting to take effect.

See also

TXTAIL(2)