2015-G8C: Digital emission modes
Which of the following digital modes is designed to operate at extremely low signal strength on the HF bands?
JT9 and JT65
FSK441 and Hellschreiber
How many data bits are sent in a single PSK31 character?
The number varies
What part of a data packet contains the routing and handling information?
Which of the following describes Baudot code?
A 5-bit code with additional start and stop bits
A 7-bit code with start, stop and parity bits
A code using error detection and correction
A code using SELCAL and LISTEN
In the PACTOR protocol, what is meant by an NAK response to a transmitted packet?
The receiver is requesting the packet be retransmitted
The receiver is reporting the packet was received without error
The receiver is busy decoding the packet
The entire file has been received correctly
What action results from a failure to exchange information due to excessive transmission attempts when using PACTOR or WINMOR?
The connection is dropped
The checksum overflows
Packets will be routed incorrectly
Encoding reverts to the default character set
How does the receiving station respond to an ARQ data mode packet containing errors?
It requests the packet be retransmitted
It terminates the contact
It sends the packet back to the transmitting station
It requests a change in transmitting protocol
Which of the following statements is true about PSK31?
Upper case letters use longer Varicode signals and thus slow down transmission
Upper case letters make the signal stronger
Varicode Error Correction is used to ensure accurate message reception
Higher power is needed as compared to RTTY for similar error rates
What does the number 31 represent in "PSK31"?
The approximate transmitted symbol rate
The version of the PSK protocol
The year in which PSK31 was invented
The number of characters that can be represented by PSK31
How does forward error correction (FEC) allow the receiver to correct errors in received data packets?
By transmitting redundant information with the data
By controlling transmitter output power for optimum signal strength
By using the varicode character set
By using a parity bit with each character
How are the two separate frequencies of a Frequency Shift Keyed (FSK) signal identified?
Mark and Space
Dot and Dash
On and Off
High and Low
Which type of code is used for sending characters in a PSK31 signal?
● = Unseen
● = Weak
● = Review
● = Learned
● = Incorrect answer