My HF Rig and Antenna

 
HF station overview
HF station overview.
Overview
My HF setup consists of a HF transceiver which is connected to a loop antenna using coax cable. Impedance matching between loop antenna and coax cable is done using an ATU and a balun.
Click on the picture to enlarge. 
Yaesu FT-920
Yaesu FT-920 transceiver.

HF transceiver
My HF transceiver is the Yaesu FT-920 multimode transceiver. Receiving range is 0.1 MHz - 30 MHz and 48 MHz - 54 MHz. Transmit range is all amateur bands from 160m to 6m except 60m. Maximum output power on all bands including 6m is 100 W. The transceiver is powered by a Kenwood PS-52 PSU.

This MF/HF/VHF transceiver offers a multitude of features like all-band all-mode operation, digital read-out, dual VFOs, RIT/XIT, split mode, full break-in on CW, notch filter, AGC off/fast/slow, noise blanker, AF DSP filter, speech processor, monitoring of transmit signal on SSB/AFSK, VOX, and all-mode squelch. Computer aided tuning is also available via the RS-232 port, and a ATU (Automatic Antenna Tuner) is buildt in. Certainly, you can do without these features, but they are worthwhile additions and will increase your operating pleasure. 

The RF output can easily be reduced to 5 W QRP using the RF PWR control.

Balun and automatic antenna tuner.
Balun and automatic antenna tuner.
ATU 
An automatic antenna tuner (SG-239 from SGC) is housed inside a weather-proof plastic box and placed close to the feed-point of the loop antenna. DC power for the ATU is supplied via the coax cable. I use a bias-tee at the radio and at the ATU (not seen in the picture). The bias-tee injects/extracts 12 VDC from the coax cable.

A broadband balun (BL2 from Elecraft) is placed between the tuner and the antenna. It is housed inside a plastic box. The balanced side of the balun is connected to the loop antenna. The balun has two impedance options (1:1 or 1:4). I've selected the 1:4 option.   

When the operating frequency is changed (or when the antenna impedance changes due to weather conditions), the antenna tuner requires RF from the transceiver to align for best match and lowest SWR. A few seconds of RF carrier at 5 W is usually enough for this task.                 


Loop skywire antenna.
Loop skywire antenna.

Antenna 
My loop skywire antenna is 43 meters long and erected horizontally. The loop is supported in 4 corners and the feed-line is connected in one of them. The antenna resonates in the 40 meter band but is usable on the higher bands as well. The ATU provides impedance matching between coax cable and antenna at all times.

The loop is made of 1 mm enameled copper wire. The 4 insulators are made of makrolon (high tech polycarbonate) and they are connected to the support points using black 1.5 mm Dyneema rope. Insulators and rope were purchased at www.dx-wire.com


   


Latest revision: May 5th, 2015 by Lars Petersen.

Home