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Reviews For: OptiBeam OB2-80+ (high performance 2el 80m monoband Yagi)

Category: Antennas: HF: Yagi, Quad, Rotary dipole, LPDA

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Review Summary For : OptiBeam OB2-80+ (high performance 2el 80m monoband Yagi)
Reviews: 3MSRP: 3,600
Description:
Extremely efficient trapless 2el 80m Yagi on a 36 foot boom with 74 foot long elements.
Lossfree shortened elements by software designed and absolutely unique high Q coils.
Fed through a high quality Array Solutions 5 KW 1:2 balun.
Robust like a tank and optically extremely attractive due to a stirdy square boom and double trussed elements.
Product is in production
More Info: http://www.optibeam.de
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0035
PA3DUV Rating: 2008-05-02
Big Bad Bonecrusher Time Owned: 3 to 6 months.
Yep, we got the 2 element 80 meter beam from Tom up and running last PACC contest.

Friday night after the beam was launched on the 60 meter boom big crane the first SSB DX pile up was cracked with 90 watts. After plugging in the three phase mains socket the fun started.

During the contest the beam proved to be invaluable. In combination with "sufficient" input power the transmit and receive performance of this big antenna was awesome.

In order to accomodate the use of multiple frequencies in the 80 meter band we have modded the base loading matching network of the stock OB2-80. By adding 2 extra taps to the big fat base loading coils of driver and reflector, designing and building two new relay boxes (with 3 relays each) the beam can now be used on four 60 kHz wide spots in the 80 meter band. All this is remote controlled from the operating position.

Obviously this monster needs a big rotator, we've used a PST71D from Prosistel to crank it around on the 60 meter high crane top.

For any details concerning the modification and pictures of the setup contact me.


Highly recommended.

73, Dick
PA3DUV
W6DUV
HB9CIP Rating: 2007-06-20
High performances into a limited space Time Owned: 0 to 3 months.
In may 2007 we erect the 2 el on 80m from Optibeam (OB2-80+). This antenna was new designed with CW/SSB Relay switching.
We appreciated very much the quality of the material as well as the rugged design, and of course the gread pre-assembly job done by Tom's team. This made the complete assembly of the antenna very easy (The CW / SSB Coil system is quite complicated to assembly).
The antenna is mounted 27m high (not very high), 3 m up a 2 element yagi for 30m and 6 m up a PRO96. We turned the OB2-80+ 90 ° on the mast to prevent influences. Anyway we didn't notice any Influences between all three antennas. To turn all three antennas on the same mast we use a Prosistel PST71-D rotor.
SWR and Bandwith is both on SSB and CW like described in the manual. We even experienced more Bandwith on SSB (3720 to 3805 under SWR 2:1). I have been very active on 80m with a triangle array of fullsize Titanex V80S verticals and have been very satisfied with this system. I still hold the triangle so I could make several comparisons. The beam is better than the triangle array in all directions in both RX and TX. On very long distances (over 12'000 Km) there is not a big difference, but under this distance it is remarquable.
It is not a cheap antenna, but if you look for a good compromize on 80m it is sure a good choice !
OE6MBG Rating: 2004-11-19
Tom did it again! Double Five! Time Owned: 0 to 3 months.
When Tom, DF2BO, indicated he was coming up with a new 80m Yagi and I knew what his workload was for the remainder of the year 2004, I realistically did not expect to see it happen before the end of the low-band season. Well, it did happen and after initial testing in Germany Tom shipped off 2 cartons containing high-level aluminium of various lengths and sizes to Austria. Being the first user of a new product is always a little risky: is it going to work? Will I need to get the antenna up and down 5 times before the tuning is right? Will there be any teething problems Tom did not think of? This may not seem of such concern when you talk about a higher frequency array, but the weight and size of an 80 meter Yagi would make any trial and error approach rather inconvenient.

Again, Tom would not be Tom if he released a product that was not short of perfect. On opening the cartons and inspecting the electrically most critical part, namely the hi-q coils, it was pretty obvious he had done his homework well. 4 large diameter coils wound on UV-resistant translucent material are mounted in a rock-solid method on very sturdy fibreglass rods. The electrical connections between the coils and the element consist of stainless-steel screws which are securely fastened and look as if it they are not going to move or loosen too easily. For me, this was the most critical part of the antenna to look at, as this is where the losses may occur and in my opinion Optibeam has done a wonderful job there. I had attempted in the past to homebrew hi-q coils, which were not bad at all, but Tom’s coils made of 3mm aluminium wire are considerably lighter than my copper models.

The antenna having arrived on Friday before CQWW 2004 SSB, I realized that my schedule would not allow me to mount the antenna any time before the end of 2 weeks – unless I was willing to sacrifice the first day of the contest, Saturday. Sitting on a mountain of aluminium and realizing the weather may not be getting any better, I decided to go for it. But how do you get 80 kg of antenna up on a 27 meter tall tower without too much assistance? All my ham-friends were contesting and needed more notice than just 24 hours…

To cut a long story short: it did work and 24 hours after the arrival of the antenna it was up on the tilt-over tower – with the assistance of my xyl and 2 TVI-infected neighbours (I promised them this antenna would cause less trouble). Nerve-wrecking though it was, everything ran smoothly and the square boom and the precise marking of the element sections made assembly very easy and straightforward. A 2:1 balun to accommodate the 25 Ohm feedpoint impedance was mounted and no tuning was necessary to put the antenna into the DX-window. Some may say the bandwidth is somewhat narrow – 60 kHz 2:1 and 40 kHz 1.5:1 – but if you want a shortened yagi with almost 6 dbi free space gain and good front to back ratio (15 –18 dB on the design software, in the real world sometimes even 20), one has to accept some sacrifices. Having tried other designs in the past – both homemade and commercial – I knew exactly what to expect and readily accepted this fact.

The element lengths are a little over 22 meters, the boom is 11 meters long and there is virtually no sag on either the elements or the boom. Cut-to length steel cable with proper lugs is used to guy the boom and cleverly designed pre-adjusted high-quality ropes that attach in 2 places on each element half keep the driver and reflector absolutely parallel and nearly droop-free. The square boom makes vertical and horizontal alignment of the elements very easy. The stainless steel element-to-boom mounting hardware looked a little fragile at first but held up very nicely even when only one element half was mounted due to my particular way of fixing the beam on the tilt-over tower.

The Array-Solutions balun is supposed to handle all the power one can run (up to 5 kW), I have not noticed any degradation in the SWR when running full power. The elements as well as the balun are mounted underneath the boom, so the feedpoint and balun are somewhat protected against the weather.

One thing I have noticed especially with this antenna in my particular RF-environment is that I seem to be getting out quite a bit better in comparison to my “yardsticks” even though the theoretical increase in gain over my previous antenna is not more than 1.5 db or 2 db. I have noticed also a lot less noise than I did on my previous yagi that had 2 driven elements. I put it down to the fact that the E- and the H-plane patterns are somewhat narrower and there seems to be less near-field pick-up from noise sources in my immediate surroundings. Another bonus I experienced from this antenna which has kept its promises so far and has exceeded my expectations – it has been a wonderful performer whenever the band lets us work any dx.

One promise, however, did not come true: Since the ERP of my system using equal transmit power than before has increased with this beam, my neighbours seem to hear me a bit louder on their stereos now, an unwanted side effect that requires the use of more ferrites and smooth talk. Well, this happens when you have a good low-band antenna. And again, my xyl loves the beam: she appreciates the fact that there are no more radials on the ground (I used a 4 square for many years) and she calls it the Optic-beam because the elements are so straight. So it is a double-five for rating. See you on 80 meters!

PS: Steve, VE6WZ was the first VE6 I worked this season on 75 on Nov 18. He was very impressed with the results of the new antenna and recorded the qso at www.qsl.net/ve6wz/OE6MBG_80ssb_04-11-18.mp3 . Thanks Steve!