Band Optimised Log Periodic Dipole Array 14MHz to 30MHz - by G0KSC
Product Dimensions and Weight
CUSTOM LPDA DESIGNS AVAILABLE UPON REQUEST
BOLPA-10 A Super Wide Band, High Performance Log Periodic Dipole Array (LPDA) - 14MHz to 30MHz Optimised for all Ham Bands Just 7.7m long!
Covers 25MHz to 30MHz inclusive.
All InnovAntennas LPDA’s are design using the very latest computer optimisation techniques and are largely designed and built to order although examples such as this Band Optimised Log Periodic Dipole Array (BOLPA) which has had its performance highly optimised wihtin the ham bands in order performance is not characteristic of a typical LPDA.
The BOLPA-10 has 10 elements placed within a twin-boom/dual feedline boom setup where 2 x 1.75'' square boomd double as the feedlines and booms. The feed point is 50Ohm so a simple choke balun can be installed between coax cable and the antenna for an easy installation.
The BOLPA-10 provides excellent, consistent results for the frequency range it covers and the relatively limited number of elements installed upon its very short boom. For more details on this or other Log Periodic developments, contact as directly now on our sales lines or via Email sales ‘at’ innovantennas .com
OUTSTANDING RESULTS FROM THIS STUNNING NEW DESIGN for 2017!!
Our customers quote SWR figures not extending beyond 1.3:1 for any of the given ham bands. In addition, exceptional level of Forward Gain and Front to Back ratio (F/B) are seen due to the way in which the BOLPA-10 is designed.
WHY DOES THE BOLPA-10 WORK SO WELL?
Log Periodic Arrays are generally produced by means of a calculator rather than being band specifically optimised and therefore, performance and SWR curves vary greatly through their range and optimimum performance is hit and miss as a result. The InnovAntennas BOLPA-10 has had hundreds of hours spent optimising both SWR and Performance within the Ham Radio designated band sections which has resulted in exceptional mono-band style performance.
SDR READY ANTENNA, 6 BAND SIMULTANEOUS PERFORMANCE!
The BOLPA-10 has all-bands-active at anyone time so will compliment the most sophisitcated SDR Tranceivers, with up to 6 slices on 6 different bands (20m, 17m, 15m, 12m, 11m, 10m) all at the sam time. With the right equipment, you can even transmit on one of these bands while listening on the other 5 bands at the same time!
Some of the Mechanical design benefits include:
- Marine grade Stainless Steel Fittings*
- Integrated feed-line/boom for maximum efficiency, minimum wind-load
- Mill finished for highest levels of accuracy and performance
- First-of-kind 'Band Optimised' LPDAs by G0KSC
The BOLPA installed at GM8OFQ - Geoff's comments below:
Antenna is now up at 50' and the SWRs have decreased :
20m - 1.35 on 14.150Mhz and 1.2 on 14.350Mhz
17m - 1.12 on 18.130Mhz
15m - 1.0 on 21.250Mhz
12m - 1.13 on 24.960Mhz
10m - 1.04 on 28.500Mhz
I have carried out several F/B tests. It appears that the F/B is well in excess of 25dB - ZS95SARL on 14.315 this afternoon was 59+20 on front and 53 on the back, this seems consistently to be the difference on most stations I tested. Yes, the location here on Hoy is a DXers dream - no noise and surrounded by water on 3 sides with the tower about 10m from the water at high tide.
The Bolpa installed at Veteran DX'er Gary, G0FWX who has 323 countries worked before the BOLPA
Garry said 'The BOLPA is amazing, Flat SWR on all the bands'
The BOLPA at G2YT - installed at 85'
Installed at G1XOW
The Twin-boom feedline of the BOLPA-10 can easily be seen in this image
If you are looking for the best of the best from both a performance and mechanical construction perspective then look no further, you have come to the right place!
Customer Comment from SJR Service, our dealer in Sweden:
'My customer with the LPDA has sent me this info:
He says he should have bough this antenna years ago!'
Note: At least one Log Periodic producer quote 8.5dBi gain typical for a 14MHz to 30MHz Yagi. As for verification of this figure. To achieve this level of gain without Ground Gain (which can add up to 5dB) would be ground breaking. All our quoted figures are verifiable within known good prediction software. For estimations of performance in your installation, send us the height above ground you will install and ground conductivity if known.
Gain: 6.9 - 7.5dBi
Typical F/B: 20dB+
Gain at 10m (33') above ground @ 14.150MHz: 11.56dBi
Power Rating: 5kw
Feed Impedance: 50Ohm
Boom Length: 7.7m
Turning Radius: 5.13m
Wind Loading: 1.4 SqMtr
Wind Survival: 160KPH+ / 100MPH +
If you wish to stack several antennas, contact us for more information
Over-lay plots on 20 through to 10m. F/B 16dB on 12m, all other bands, 20+dB
This antenna has all elements made from 1.25 inch aluminium thick wall tube (largest element) tapering down to 3/8''.
The boom is 1.75'' inch square (44.45mm) which is in 3 sections. two sections of boom form the feedline and antenna element support, the third section provides a boom support truss.
If you want an antenna to last and perform in all weathers without SWR or bandwidth shifting, this is it.
Manufactured the right way, not the cheapest way!
* Where possible marine grade stainless steel components are used.