MFJ cub QRP CW Transceiver
Operation Manual
4
Headphones:
Use
standard walkman-type stereo headphones exhibiting 8-40
ohms impedance (higher-quality headsets often yield better performance).
Alternatively, plug in any extension speaker with a similar load impedance.
Be
sure to use only stereo type plugs
--a mono plug will short the radio's audio
output to ground!
NC
Audio Line
Keys and Keyers:
Use any hand key or electronic keyer with a 3.5 mm plug
(mono or stereo plug okay). Connect the key line to the jack's tip and the
common line to the sleeve.
NC
Key Line
NC
Stereo Plug
Mono Plug
Key
Key
Antennas:
The
cub
is designed to work with any efficient 50 ohm antenna
exhibiting a VSWR of 2:1 or less. Suggested dipole lengths are shown in the
following diagram, along with data for adding a simple coaxial choke-type
balun:
17 Meters: 25' 10"
15 Meters: 22' 2"
20 Meters: 33' 2"
30 Meters: 46' 4"
40 Meters: 65' 10"
80 Meters: 130'
Length
Coax Balun
17 Meters: 7', 8 turns
15 Meters: 6', 8 turns
20 Meters: 8', 8 turns
30 Meters: 10', 7 turns
40 Meters: 15', 6 turns
80 Meters: 20', 8 turns
RG8X or RG58
For best performance with any antenna, install as high and in the clear as
possible.
The ARRL Antenna Handbook, The ARRL Antenna Compendium
, and
many other amateur publications--including several from MFJ--offer additional
antenna tips and suggestions.