Review of AOR LA320 by Chris Lorek

Together with the significant number of decicated HF receivers, an ever-increasing number of scanners now also have HF(High Frequency, or ‘Short Wave’) coverage, some even having SSB facilities. A short length of wire used as an aerial can often give you disappointing results on the ‘lower’ HF ranges, but not everybody has the facility of being able to connect a long wire outdoor aerial with its associated aerial tuner, or dedicated resonant aerials, for this. Another problem which many of us face in this ‘electronic age’ is that of electrical ‘hash’ from our neighbours computer, Tv’s, and so on. A directional aerial helps here, but such an animal for, say, the 41m broadcast band tends to be a bit large at around 20m long, rotatable!

With this in mind, AOR have complemented their wideband aerial range with the LA320. This is a ultra-compact loop aerial, specifically designed to improve reception when located indoors. As supplied it comes with two plug in elements, a black shrouded ferrite loop for 1.6MHz-5MHz, and a metal shrouded loop for 5-15MHz. Each of these plug into the plastic base unit, which houses a varicap tuning circuit and RF amplifier arrangement, powered from a PP3 sized 9V battery fitted within the base. Optional plug in units are also available for 0.2-0.54 and 0.54-1.6MHz.

Everything, including the coax patch lead to your receiver and even the 9V battery, are supplied, so all you need to do is to simply connect up. The large black knob on the base unit acts as an on/off and tuning control, this being adjusted for maximum signal strength at whatever frequency your listening to at the time. After doing this, I found by placing the aerial on a window sill, I could get very good performance and effectively ‘null out’ virtually all the noise from my computer system located within the house, but possibly more importantly I could also ‘peak up’ on weak broadcast signals whilst reducing the level of unwanted adjacent broadcaster from a different direction - superb!

I often found there was rather to much ‘gain’ from the aerial due to its internal preamp, even my outdoor(33m long)HF trap dipole yielded considerably less signal level than the LA320 provided, and I normally had to keep my receiver’s attenuator switched fully in to prevent overloading. Although many dedicated HF receivers will cope with this, as did the FRG-100 I tested the LA-320 with, some handheld scanner receivers would undoubtedly just ‘curl up’.

AOR (UK) kindly also sent me the optional LF loops. These really came into there own for semi-serious MW/LW broadcast band ‘Dxing’, especially at night when the directional advantage of the LA320 would nicely ‘null out’ one or more of the many stations on the same frequency, almost like a large frame aerial but a fraction of the size.

In all, I found the LA320 systems should be very useful in those cases where either a long outdoor wire aerial would be difficult for reception of the ‘lower half’ (i.e. 15MHz and below) of the HF spectrum, as well as for DX reception on the lower part of the frequency range. It had a good directional capability in the small size, useful for nulling out unwanted signals, but make sure your receiver has a switchable attenuator otherwise you could have problems with overloading.

May 1993 - Scanners International is a section of Ham Radio Today Magazine published by Nexus Special Interests Limited, Nexus House, Boundary Way, Hemel Hempstead, Herts HP2 7ST, England. Tel: 01442 66551 Fax: 01442 66998, editorial e-mail: editor@qsp73.demon.co.uk editorial web site:
http://www.qsp73.demon.co.uk

Due to continuous developments, AOR reserves the right to make design and specification changes for product improvement without prior notice. The performance specification figures indicated are nominal values of production units. There may be some deviation from these values in individual units.

AOR LA320 Mini-Review

Chris Lorek tests AOR’s new range of active loop aerials for HF use