NEW - CONTEST RESULTS
Second place, RSGB VHF Activity Contest (January
2008)
I used my SB5 to get second place in the Open Section
RSGB Activity Contest for January 2008.
Check it out
here.
When looking at the results note that I was using a
smaller antenna and lower power than all other similarly placed
competitors - the SB5 really works well!
73 Richard G3CWI
Superb Performance - designed for portable use
The SB5 is a 5 element wide spaced Yagi for 2m. Created
in response to customer demand for a high-performance Yagi suitable
for contests and demanding SOTA activations. The SB5 builds on the
experience we have gained with the popular SB3. With its super-clean
radiation pattern, high gain and light weight the SB5 is sure to
become a favourite for all sorts of portable operators. The 1.5 metre
boom splits into two making the SB5 easy to carry either on a backpack
or in the boot of your car. It has been designed for use in the field
- it is quick and easy to assemble.
Two antennas in one!
A unique feature of the SB5 is its ability to be used
as a highly effective three element Yagi. The Stubby is just
48cm long and can be used when weather conditions preclude use of a
larger aerial.
Tried and tested
The SB5 builds on experience gained from hundreds of
happy users of our famous SB3. The SB5 has been extensively tested to
make sure it works well for YOU! Based on a design by Martin Steyer,
DK7ZB (used with permission - thanks Martin).
Features
 |
High gain (10.5dBi) - equivalent to increasing
power by nearly 7 times compared to a dipole (by 9 times compared to a
halo)
|
|
Clean radiation pattern (all lobes better than
-20dB)
|
|
Super front-to-back ratio nearly 30dB
|
|
Light weight (just 400gm)
|
|
Mounting brackets built-in (vertical and
horizontal)
|
|
NEW 100W recommended power
rating
|
|
Feed line choke - keeps pattern clean
|
|
Elements store in boom - easy to carry
|
|
Fast to assemble - be on the air in minutes
|
|
Two-section boom for easy transport
|
|
Ready fitted BNC plug
|
|
3mm solid rod elements for low wind resistance
|
NOTE - The SB5 kit requires
limited self-assembly (approx. 30 minutes). All parts and
easy-to-follow instructions are supplied.
The Big Advantage
As the SB5 is so light, it is easy to support at a
much greater height than can be achieved with larger Yagis. Even on an
elevated site, antenna height above ground is critical to good
performance.
As an example, here is the terrain profile from a
contest site I sometimes use (click to enlarge). This site has ground
that falls rapidly away and many people would think that antenna
height above ground here would make little difference to the system
performance.
If we now simulate a good 10 element beam (5+5) at 2m
above ground and compare it to a single 5 element beam at 10m above
ground, the single 5 element is better in the critical low angle range
(0-3 degrees). Thus even in the most favourable circumstances a high
SB5 can outperform larger antennas that are tricky to elevate. The
graph shows the relative performance of the two antennas at different
takeoff angles. For VHF, low takeoff angles (0 to 3 degrees) are most
important. The simulation uses the terrain profile combined with a
diffraction and reflection analysis to predict the system performance.
Now let's examine the same site but in a different
direction. Here is the terrain profile. This is much less favourable
and is probably more typical of an "average" site in rolling
terrain.
In this case the single SB5 would be over 4dB better
than a good 10 element beam! That's the equivalent of running nearly
three times more power.
The weight advantages and low wind resistance of the
SB5 allows it to outperform much larger antennas in real situations.
What's new? Click photos to enlarge
| 5 elements for higher gain |
|
 |
| Superb clean radiation pattern |
|
 |
| Feedline choke for optimum antenna pattern |
|
 |
| Use as 3 element beam in windy weather |
|
 |
| 25 Watt power rating (400W with Contest Pack) |
|
|
| Usable on 70cm in emergency (performance not guaranteed) |
|
|
| Element identification system for fast assembly |
|
|
| Easy to stack for even better performance with Contest Pack
(available soon) |
|
|
| Built-in storage for assembly parts |
|
|
| Releasable cable-ties for quick deployment |
|
|
| 4 guy system for greatest stability |
|
|
The SB5 Full kit includes:
|
One super-light (400gm) high performance SB5
|
|
One guying kit (4 guy version)
|
|
One 7m mast (antenna mounts at 4m)
|
|
One feeder system including feedline choke and BNC
plug (fitted)
|
|
Detailed instructions for initial assembly and use
|
|
Access to web-based user-support
|
Click here for packing list.
Reviews
Richard,
I took the Sota five-element beam on to the
Pennines today and had a great time on two metres.
...The instructions are commendably lucid and
there were no mishaps.
...It was pleasing, on about four watts, to
receive S9 reports from Lincolnshire, Cumbria and the Yorkshire Dales
in flat conditions. Even better was to swing the beam on to a barely
audible signal only for it to leap to 5/9. It shows terrific gain over
our home-brew three-element.
A nice piece of kit Richard, meticulously thought
out...
Thanks, Bob 2E0PIE
ORDER HERE
SB5 Full Kit (beam,
6.5m feeder,
7m mast, guying system) just £69.95
SB5 Basic Kit (beam, 6.5m feeder)
£54.95
Postage and packing extra.
Order by phone
Call us on 01625-425700 to place
your order by credit or debit card. This
is our preferred payment method!
Delivery
UK orders are send by
Parcel Force Standard Parcel service. This typically takes 5-7 working
days. If you want a quicker service, Parcel Force 48 costs an
extra £6 and Parcel Force 24 costs an extra £10.
ONLINE ORDERS
Destination
|
SB5 Full Kit £69.95
|
SB5 Basic Kit £54.95
|
UK
|
+£6.00 p&p
|
+£6.00 p&p
|
Europe (EC Countries including Ireland)
|
+£32 p&p
|
+£32 p&p
|
USA
|
+£40 p&p
|
+£40 p&p
|
SB5 Spares kit
£4.50 + 50p p&p
Includes:
1 yellow endcap
1 black soft rubber end cap
12 element end caps
6 O rings
2 Crocodile Clips
Overseas
customers please note that we can often send two or even three
beams at no increase in postage due to the weight bands. Please
contact us to ask for details if you wish to order two or more items.
Postage costs are high due to the
length of the package.
Orders by post (cheques in UK
Pounds) always welcome.
|
