Operating Techniques

Question 1

Operating a Packet Radio Station

Answer 1

The amateur addresses the message with the destinations callsign directly and “connects” to the far station, which must have a similar setup. The far station automatically confirms connection, and messages can be sent back and forth in real-time much like other digital modes such as RTTY or PSK31.

Question 2

Packet radio to a station out of range or a number of other stations

Answer 2

In order to contact the distant station the packet message is sent in short hops via other stations that are in range of each other. The stations act like repeaters and are known as digipeaters. Most normal packet stations can also be used as digipeaters. This this to work the TNC must be made aware of the address of each station in the chain. Once connection has been established messages can be exchanged in real-time without further intervention as the TNC handles all the protocol.

Question 3

Packet radio via mailboxes or Bulletin Board Systems (BBS)

Answer 3

Mailboxes are special packet stations (use GB7 call prefix in UK) which can accept your message for later reading by the recipient. Similar to email. It can either be for someone local to you in which it will stay in local mail box or it may be forwarded to a remote mailbox. This is routed by the call sign and handled automatically. Typically high speed links on VHF, UHF or microwave. Occasionally on HF, satellite or undersea cable. May take sometime for message to get through. To run a mailbox you must obtain a NoV.

Question 4

Packet radio in a DX cluster network

Answer 4

This works in a similar way to mailboxes. DX cluster spreads DX information in near real-time. It indicates spots of interesting DX stations on air together with their frequencies. Amateurs who have heard the stations enter the details on into the system.

Question 5

Repeaters

Answer 5

2m band 144-146MHz use a repeater shift of 600KHz. Input is lower than output. E.g. Listen on output 145.650 input is on 145.050
70cm band 430 - 440MHz input is 1.6Mhz higher than output. E.g listen on 433.100 transmit on 434.700MHz
Short 1750Hz tone or continuous sub-audible tone (CTCSS) required to open repeater and prevent accidental re-transmission of signals.
Repeaters may automatically shutdown if overs are too long.

Question 6

Special Event Stations (SES)

Answer 6

To operate a SES

1) must be for an event of significance
2) Generally accepted as one requiring celebration
3) Open to viewing by the public
4) Supervised by full licence holder
5) Applied for at least 28 days in advance

Question 7

Band Plans

Answer 7

Agreed with the International Amateur Radio Union (IARU). Not enforceable by law but are essential to avoid interference with other band users.

Question 8

Band Plans patterns

Answer 8

Broad pattern to remember wideband modes such as SSB placed at high frequency ends of bands, narrow band such as CW appear at low frequencies on most bands.

Question 9

Band Plan Restrictions

Answer 9

Examples
30m (10MHz) no wide band operation
12, 17, or 30m (24, 18 and 10MHZ) no contests.