4.7 HF Packet Operation
HF Packet is much trickier than operating on VHF. In this section we
will assume you have as completed section 4.2 of this chapter and at
least read section 4.3 and the MONITORING sections of 4.4. If at all
possible, get some experience with VHF packet before trying packet on
HF. Although this is not absolutely required, the experience will
help you make HF packet contacts.
4.7.1 Where to Operate HF Packet
Before you can operate HF Packet, you find the activity. Most HF
packet operation is on the 20-meter amateur band starting at 14.103
MHz and every 2 KHz above that up to 14.111 MHz. Note that 14.103 MHz
is the calling frequency and a good place to start. The higher
frequencies such as 14.109 and 14.111 are used mostly by HF PBBS
systems and are not good places to look for a QSO.
4.7.2 PK-232 HF Packet Settings
Make sure your PK-232 is turned ON and your PAKRATT or terminal
program is up and running. Then change the following PK-232
parameters for 300 baud HF Packet. The VHF settings are also shown to
make it easier to switch back to VHF when finished.
300 baud HF Packet 1200 baud VHF Packet
SLOTTIME 8 SLOTTIME 30
PACLEN 64 or less PACLEN 128
MAXFRAME 1 MAXFRAME 4
FRACK 15 FRACK 8
HBAUD 300 HBAUD 1200
VHF OFF VHF ON
The last two of these commands are the most important.
If you fail to set the VHF parameter to OFF, the VHF modem will remain
on and you will not be able to copy packets. Similarly, if you do not
set the packet baud rate (HBAUD) to 300, you will be operating at a
different speed than everyone else and not be able to copy any packets.
You should set MONITOR to 6 when you first try to tune in HF packet.
4.7.3 HF Receiver Settings
Set your HF receiver (or transceiver) to Lower Sideband (LSB) unless
you connected your PK-232 through the direct FSK keying lines, in
which case you should select the FSK operating mode. Adjust the
volume to a comfortable listening level.
4.7.4 Tuning-in HF Packet Stations
Perhaps the most difficult thing about HF Packet operation is making
sure the station you are talking to is tuned properly and stays tuned.
Since HF packet uses 200 Hz Frequency Shift Keying to send data
(2110/2310 Hz), tuning accuracy is very important. Being off
frequency by only 20 Hz makes a noticeable difference in the PK-232's
ability to copy packet stations. Follow the tuning procedure below
carefully for the best results in tuning in HF packet stations.
4/91 4-23
