Assembling and using your antenna
Assembly:
The model HF-315 loop antenna is designed to be ultra portable and is very quick & easy to deploy.
The antenna can be used either with or without the included support which is constructed from 1/2-
inch schedule 40 PVC pipe. The HF-315 can be mounted to a photo tripod if desired, and a standard
1/4x20 female thread mount is located inside the bottom of the PVC antenna support for this
purpose.
In some cases such as long-range hiking, mountain climbing, etc. it may be desirable to take along only
the coaxial loop element and the tuning/coupling unit so as to minimize weight. This way weight of
the antenna system is just 1.5lbs.(0.7kg.). In these situations, the PVC loop support can be left behind
and the loop may be supported simply by hanging from convenient natural objects such as trees, tall
bushes, large rocks, etc.
In other cases such as camping, hotel/motel room use, use in apartments, ham radio demonstrations,
or any other place where a very compact yet high performance HF antenna is needed, use of the
antenna with the provided PVC support may be best.
Assembly of the antenna is very simple and involves these steps:
(Refer to figs. 1 & 2 on the following pages for illustration of assembly)
(If not using the included antenna support then uncoil loop coax and proceed to step 3)
1) Assemble the antenna support if you are going to use it. (refer to fig. 2 on page 6).
2) Uncoil the coaxial loop element and insert into the “Tee” connectors at the ends of the PVC
support arms. The tees are cut so as to allow quick insertion and removal of the coaxial loop
element without the need to disconnect/reconnect the tuning unit each time.
3) Connect the male connectors at each end of the loop coax to the corresponding female
connectors (Marked “LOOP”) on the tuning unit. IMPORTANT: For proper operation, the loop
connectors must be clean and tight at all times during antenna operation.
4) Connect an appropriate cable between the “RADIO” connector on the bottom of the tuning unit
and your radio. The antenna is now ready for use.
Initial Tuning
Tuning the loop antenna is very simple. First, select the frequency on which you wish to operate.
Second, adjust the “Tuning” control on the loop tuning unit for maximum background noise level on
receive. If you only wish to receive (i.e. SWL), then no other steps are needed. For transmit operation,
one additional step is needed: Key the transmitter on CW/AM/FM or any continuous carrier mode,
using about 5-8 watts of power. Readjust the “Tuning” control on the loop tuning unit for minimum
SWR If an SWR indicator is available. See Page 8 for further discussion regarding transmit tuning.
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