2 Element DXPedition Style Delta Loop
(Super Lightweight) As used by 130SD/DX, 197SD/0 and 223DX/1



2 Element DXPedition Style Delta Loop
(Super Lightweight) As used by 130SD/DX, 197SD/0 and 223DX/1

A 2 Element Super Lightweight Delta Loop Antenna for the 11m band


Product Code – 11M2_DXPed_WWSuperLIGHT

Early in 2013, Vortex were contacted by the ‘197SD/0 Vanuatu DXPedition’ team who saw a potential partnership between Sugar Delta and Vortex. The Delta Loop is electrically similar to the Quad Antenna and the full wave loop design has advantages over the typical ‘Yagi’ design. On modelling, the Delta Loop shows a lower angle of radiation when compared to a Yagi at the same height. Also, the main radiation lobe is two-thirds up the sides of the antenna, rather than at boom height. All in all, this makes the loop a favourite for DX work, especially as a closed-loop array is also known to be less prone to noise and having a quieter receive. The antenna designed for 197SD/0 is an updated version of the one used by Matt 223DX/1 for the 2011 Delta-XRay DX-Pedition to Western Samoa. This activation proved very successful with many EU stations making it into the log including quite a few from the UK. The same system was also used by the team from Sugar-Delta New Zealand for the 130SD/DX activation of Norfolk Island.

The Delta Loop for 197SD/0 has been personally designed and constructed by Steve from Vortex. Knowing that weight limitations are paramount when considering a DXPedition, this second version has been modified to include a 3 section telescoping vertical section (rather than two) with 16, 12 and 9mm 6082-T6 aluminium tubing. By using three sections, it means that the max length of any one part of the antenna does not exceed 1.85m with the 1.85m longest part being the boom. It also saves on weight. Each element section is a max of 1.5m so this makes for easy transportation especially on aircraft.

Lightweight 6082-T6 ‘V’ brackets together with standard polyamide ‘Stauff’ clamps are used to hold the elements in place. The delta loop top wires (normally heavy duty Flexweave) have been replaced by 18 gauge coated wire which is much lighter than the Flexweave but very strong for its size. The antenna is matched by a Vortex Gamma Match as used in other antennas in the range. This is rated at 3.5kw and uses a PTFE insert manufactured by ‘Polyflon Technologies’ in the UK. The antenna is rated at 1kw which is governed purely by the top wire gauge. The use of normal ‘Flexweave’ as in most of the Vortex designs will see the rating rise to 3.5kw. Flexweave wires are used to link the loop ends and A2 stainless hardware completes the setup.

During a period of extensive testing, the loop proved very quickly that is was working exceptionally well even at a low test height of only 5m. Forward facing signals of S9 were reduced to S1-2 when the antenna was turned 180 degrees. This says the front to back ratio is extremely good and in real terms is over 25db. Forward gain is modelled at around 7.4dbi and although on paper is a fraction less than a full size optimised 3 element Yagi, actual on-air performance suggests the Delta outperforms the Yagi especially on the longer distance DX mainly due to the lower angles.

Bandwidth is to be as expected at around 2MHz with the band center set at around 27.570 MHz.  Lower 2 to 1 limits are around 26.900 MHz and higher 2 to 1 limits are at 28.900 Mhz, so in essence the antenna could also be used on 10m if required with slightly reduced front to back. The curve is typical for this type of design with a steeper curve on the lower side of resonance and a much shallower curve on the higher side. During testing, the SWR from 27.170 MHz to 28.470 MHz remained at 1.5 to 1 or below so easily workable without an ATU.

All in all the antenna makes an excellent choice for the ‘DXPeditioner’ and in total weighs in at a mere 5.6 kg. The total weight also takes into account a small 8mm diameter 6082-T6 aluminium mounting plate and stainless saddles and U-Bolts which we aslo include in the package. The unit can be packed into a container less than 2m in length (ie a fishing pole/rod holder). You can see below, that even with poor conditions the loop performed very well.

See info below for mechanical and electrical details

  2 Element ‘DX-pedition Style’ Delta Loop (Super-light) – 11m

Band(s):  11m (27Mhz)
Element Material:  6082-T6/*AA6082-T6
Boom Material:  6082-T6 box section aluminium
Boom Length:  1.9m
Gain:   7.4dbi
Front to Back Ratio:   Better than 25db
Feed:   Coax via SO239 socket
Matching:   Vortex Gamma Match (PTFE dialectric)
Rating:   1kw (Only limited by smaller guage top-wires)
Element Clamps:   Stauff (Germany) – standard duty polyamide series
Loop Top Wire:   PVC Coated 18 guage
Antenna Weight:   5.6kg
Hardware:   304/316 stainless steel