New BOLPA antenna unveiled

InnovAntennas Limited, the premier supplier of sophisticated and Innovative directional antenna systems announces today the release of a game changing HF multiband directional antenna; the new Band Optimised Log Periodic Array (BOLPA).

The first in the series of BOLPA Yagis provides exceptional performance on 5 HF Ham bands simultaneously form a single feed point so is ideally suited to the modern-day SDR radios such Apache Labs, Flex Radio Systems and Expert Electronics where multiple band receiver slices can be used at the same time.

What makes the BOLPA different to traditional Log Periodic Arrays (LPDA)?

The BOLPA is a result of 2 years’ worth of development and testing. Justin Johnson G0KSC embarked upon a project to test the monoband abilities of a log periodic. It is known that an LPDA in traditional form can provide usability over a very wide range. However, the compromise being performance in terms of gain and Front to Back (F/B) are generally average to poor.

The project started with Justin optimising a 3 element LPDA for the 20m band only. This produced an antenna with a very short (6’, 1.9m) boom with just under 7dBi forward gain and almost 25dB F/B.
The BOLPA came from the combination of several Monoband logs, arranged upon the same boom. To start with, 3 x 3el monoband LPDAs where placed one in front of the other for 20m, 15m and 10m. Performance of each was excellent and a bonus band materialised from this 9-element array; 12m was delivered for free!

Therefore, this first pass with 9 elements gave 20m, 15m, 12m and 10m all in a very short package but 17m was missing. Justin shifted the 20m 3 element cell back on the boom and placed a single element between the 20m cell and the 15m cell and optimised this element for lowest SWR for 17m while carefully adjusting the position of the 20m and 15m cells ever side of it. The result? The BOLPA-10 which covers all bands from 20m through to 10m (usable right up to 30MHz) with exceptional performance throughout.

Not only did the director for 20m provide a reflector for 17m and the first of the 15m elements provide a director for 17m ensuring excellent results on that band, the dedicated 17m element added an additional element to the 15m cell (now totalling 4 close-spaced elements) which delivers over 7.5dBi on this band along with 28dB F/B.

The first customer reports have confirmed SWR figures on all ham band of around 1:1.1 with 12m reaching as high as 1:1.3. on the upper end of the HF spectrum, the BOLPA-10 remains extremely stable across 6 MHz (between 24MHz and 30MHz) resulting in another benefit on all bands for valve amplifier users, No retuning because of same-band QSY!

Mechanical Construction and Feed Requirements

Unlike many traditional LPDAs, the BOLPA-10 does not have a 200Ohm feed point, like all InnovAntennas Yagis it has a direct, 50Ohm feed and therefore, simple 1:1 or choke baluns can be used and in turn, this means higher power handling abilities (5KW+). In order the reduce complexity, the BOLPA-10 using twin, square booms one about the other which double as the feed lines between each element which again improves the ability for the antenna to handle QRO.

The BOLPA-10 is the first in a new generation of high performance directional antennas suited to getting the very best from the very latest SDR transceivers. More information and ordering can be done via the InnovAntennas factory in this UK who direct supply with very competitive shipping prices, the World over.

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Email: sales@innovantennas.com

Tel: +44 203 384 0072

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