MFJ 1621
User Manual: MFJ-1621
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MFJ-1621 PORTABLE ANTENNA
WARNING:
1.
Never touch the telescoping whip while transmitting. It can cause
severe RF burn.
2. Never place the MFJ-1621 in rain or expose to adverse weather
conditions.
NOTE: 1. The telescoping whip must be fully extended for proper operation.
2. The coax cable must be fully stretched out and not coiled up or
crossing.
OWNER'S MANUAL
CAUTION: Read All Instructions Before Operating Equipment.
MFJ ENTERPRISES, INC.
P. O. BOX 494, MISSISSIPPI STATE, MS. 39762, USA
© MFJ ENTERPRISES, INC.
Thank you for purchasing the MFJ
-
1621 Portable Antenna. This antenna
will operate on 7, 10, 14, 21, 24 and 30 MHz. Maximum input power is 200
watts. In addition a field strength meter is built-
in for ease of tuning.
With the MFJ-1621, you can
enjoy operating your rig in remote locations
(camping, motels, field day, etc). where a regular antenna may be difficult
to set-up and it does not require a ground plane. Keep in mind
that this
antenna is not intended to permanently replace or out perform
a regular full
size antenna (dipole, beam, etc). It is designed to allow
you to operate
when no other antenna is available.
GENERAL INFORMATION
The inductor of the MFJ-
1621 is tapped to match the telescopic whip
supplied when it is fully extended. SWR b
elow 2:1 can be obtained in most
cases. Note that although the BAND switch is labeled for certain bands of
operation, there will be cases where you will find that the minimum SWR
occurs with the BAND switch set to a different band. This condition is
normal.
Fifty feet of RG-58/u cable is provided to allow you to locate the
antenna where it is best for operation. Keep the antenna clear from
metallic objects and other obstacles which may interfere with operation.
Since RF is presented at the antenna, it is important that the plastic
tubing be placed over the whip to avoid RF burns to bystander. Also, it is
a good idea to anchor the unit when it is windy.
INSTALLATION
Connect the transceiver to a SWR/Wattmeter with a short piece of RG-
58/u coax cable. Connect the 50 feet coax cable of the MFJ-1621 to the
SWR/Wattmeter. See Figure 1. Install the telescopic whip to the MFJ-
1621. Secure the whip with the two set of screws.
Figure 1
OPERATION
CAUTION : Don't touch the antenna when operating. It will cause an RF
burn.
1. Connect the MFJ-1621 as described above.
2. Extend the telescopic whip fully and install the plastic tubing over the
whip. Locate the MFJ-1621 close to the transceiver.
3. Set the transceiver to the desired band and frequency.
4. Set the BAND switch on the MFJ-1621 to the desired band.
5. Transmit at low power.
6. Tune with the MATCHING control on the MFJ-
1621 to obtain minimum SWR.
Note that the BAND switch on the MFJ-1621 is marked with more than
one
position per band. Try all positions to achieve the best SWR. If
minimum
SWR still is not found, try all band switch positions. If more
than one
setting gives the same SWR, use the setting which gives maximum field
strength.
7. After obtaining minimum SWR, relocate the MFJ-1621 to a desirable
location for operation. CAUTION : Keep antenna away from high traffic
area. Avoid area where children may be present. The Antenna may be
placed on the ground.
8. The 50 feet coax cable must be stretched. out. It must not be coiled.
The coax cable must not cross itself.
9. After properly locating the antenna. Check SWR again at low power. If
SWR
is high, final touch-up to get lower SWR may be necessary. This
may be
done by tuning the MATCHING control so that maximum deflection on the
field strength meter occurs. Adjust the SENSITIVITY control to get
desired meter deflection. When minimum SWR is obtained with antenna
at the
remote site, maximum power up to 200 watt may be applied.
OPERATION HINTS
Keying the transmitter may be present a problem when you are tuning the
antenna at the remote site. We suggest that you use a pair of wires long
enough to extend from the antenna to the transceiver. One end of the wire
connects to the CW KEY jack on the transceiver and the other end to a
momentary SPST switch. See Figure 2. This will allow you to key the
transmitter at the antenna when you are tuning the MFJ-1621. Use a .01uf disc
capacitor across the key jack end of the wire and one across the switch. DO
NOT TOUCH ANTENNA WHILE KEYING THE TRANSMITTER. IT CAN CAUSE SEVERE RF BURN.
