JC-4s manual version 9.1 page 8
We surely understand that the above antennas 1 & 2 may be difficult to obtain in practice. The
purpose of the use of a coupler is to be able to operate your transceiver under the worst
conditions! That’s why we consider acceptable any antenna system that provides adequate wire
lengths to operate the coupler with the maximum power, if maximum power operation is the
goal.
The antennas suggested above demand an artificial ground system to operate. If this is by all
means impossible to be obtained in our house, we suggest the following types of antennas:
3. Unsymmetrical dipole with the longer wire connected to antenna B and the shorter wire to
antenna "Α" and the antenna switch for antenna “A” operation. (Internal antenna jumper selected
to “GROUNDED”!)
4. G5RV antenna type with open wire feeder (450 Ω) connected as the dipole case above. (Internal
antenna jumper selected to “GROUNDED”!)
We recommend to study the website of www.pa0fri.com and hit “ATU” and read this article about
the JC-4. A lot of explanation is written there.
Do NOT use a shortened 1:1 balun with a coil
between the connections A and B!!
In the webshop of Stockcorner we have ready made current baluns available. This baluns are
produced by our partner Ferrite Applications. The owner is Hugo ON7FU. This balun is specials
designed for Stockcorner tuners.
5. Many users use antenna solutions like an inverted L or even as a sloper.
G: REMARKS OF TUNER OPERATION
1. The closer we use an antenna to its resonant frequency (λ/4), the more power we can apply to it via
the coupler, because in this condition the coupler is using the least of its components to match the
antenna and there is no possibility of overheating inductors and capacitors!
2. The lower the power we use, the less restrictions apply for the used antenna. This means that
operating with the standard 100W, any antenna vertical or horizontal from 6 to 60 meters can be
used.
3. The performance of the system depends on the used antenna and counterpoise. The role of the
coupler ends when the SWR is reduced to the lowest in any case possible level. If at the particular
frequencies we wish to transmit the SWR is not low enough and going a little up or down in
frequency almost falls to 1 : 1, we can fix the problem by playing with the length of the antenna.
4. In case we face problems, we act as follows:
- We check and fix the counterpoise system.
- We ensure that any wires, cables or metal posts are located far enough from the antenna
and the directions are perpendicular to the antenna.
- We use another transceiver which is in a good condition to check the system.
