SOTA – Mt Marulan to Canberra 95 km on 23cm QRP

Posted on 29/12/2018 by Andrew VK1AD

Sunday 9 December 2018. Mount Marulan (QF45XF) VK2/ST-039 868 metres ASL, Southern Tablelands NSW

GPS track route is available here. The walk is an enjoyable 2.1 km stroll, allow 45 to 60 minutes to reach the trig station.

Andrew VK1DA and I are undertaking a SOTA activation of Mt Marulan. Andrew and I have learnt that two stations operating on HF frequencies and within harmonic frequency range is a recipe for disaster. For this activation Andrew is operating in the HF spectrum mainly on CW mode while I operate in the VHF-UHF spectrum using voice single-sideband. Both stations can operate at the same location, at the same time without causing interference to each other 🙂

FT-817ND for operations on 2m 144.2 MHz SSB and the IF source 144.150 MHz input to the 23cm transverter

12el 23cm DL6UW Yagi and a 4el 2m Yagi both pointing south west to Canberra. To reduce the potential for feedline loss, the 23cm transverter is mounted as close as possible to the rear of the yagi. The feedline is a 150 mm length of semi-rigid RG402.

23cm 12el Yagi. Driven element is a folded dipole terminated in an N-type socket. Feedline is 50 ohm RG402 semi-rigid coax. 90 km over the horizon is Al VK1RX on Mt Ainslie VK1/AC-040

Hot day on the summit with limited shade

Mt Marulan stone trig station at 868 metres ASL

23cm 1296.150 MHz signal path over 90 km

Mt Marulan VK2/ST-039 to Mt Ainslie VK1/AC-040 95 km signal path overlay on Oz Topo

Extract of VK1AD SOTA Activator Log: 9 December 2018 – Mount Marulan

Grid Square: QF45XF. Operation is on 2m 144.2 MHz SSB at 5 watts and 23cm 1296.150 MHz SSB at 2.5 watts.

Summit to Summit QSOs: Al VK1RX and Tony VK1VIC both at Mt Ainslie VK1/AC-040 (QF44NR)

Time	Call	Band	Mode	Notes
23:37z	VK1RX/P	144MHz	SSB	QF44NR Al s58 r59 S2S VK1/AC-040 95 km
23:41z	VK1AT	144MHz	SSB	QF44MS Jim s57 r51 97 km
23:43z	VK1MT	144MHz	SSB	QF44NM Matt s59 r57
23:45z	VK1DI	144MHz	SSB	QF44MS Ian s53 r51
23:56z	VK1KW	144MHz	SSB	QF44MT Rob s53 r53
00:00z	VK1RX/P	1296MHz	SSB	QF44NR Al s51 r55 S2S VK1/AC-040 95 km
00:04z	VK1AT	1296MHz	SSB	QF44MS Jim s41 r41 not on a summit 97 km
00:13z	VK1VIC/P	1296MHz	SSB	QF44NR Tony s51 r53 S2S VK1/AC-040
00:14z	VK2VIC/1	1296MHz	SSB	QF44NR Tony s53 r53 S2S VK1/AC-040
00:26z	VK1MT	1296MHz	SSB	QF44NM Matt s53 r41
00:31z	ZL3GIG/P	14MHz	SSB	Ian s57 r35 S2S ZL3/CB-759
00:40z	VK1MA	144MHz	SSB	QF44MT Matt s51 r21

SOTA – VK1 1.2 and 2.4 GHz from Booroomba Rocks 1382 m ASL

Posted on 29/12/2018 by Andrew VK1AD

Sunday 1 July 2018 – SOTA activation of Booroomba Rocks 1382 metres (4537 ft) ASL, Namadgi National Park on 23 and 13cm (1296 and 2403 MHz)

To secure four unique callsigns on 23 and 13 cm, one needs to plan ahead by informing interested parties at least 2 days out, well that’s the story in VK1. It’s just as much fun organising chasers as it is hiking up the mountain. 🙂 I’m taking advantage of the well-known VK1 VHF Dx Net group who are on air from 0800h to 0900h local (2200 to 2300 UTC). For me and my plans to activate Booroomba Rocks it means a very early start at the base of Booroomba Rocks in the dark, it’s winter in this region of eastern Australia. The 240 metre vertical ascent over 2.2 km takes about 1 hour, I made the summit by 0730h local with 30 minutes up my sleeve to set up.

Looking south to Booroomba Rocks highest point. That’s my target, time is currently 7 am and the weather is looking good. I have just spent 40 minutes climbing in the dark with a headlamp. The summit is a further 20 minutes away.

Great view of the Moon

Sun just peeking over the horizon – I’m now at 1300 m ASL

At the summit and this is the view north to Canberra which is now under the clouds

90 minutes later

Rock Pools are solid blocks of ice, overnight temperature was minus 5 degrees C

VK1AD SOTA shack at the summit

Equipment carried to the summit

Yaesu FT-817 for 2m and as the IF for 23 and 13 cm transverters.

Extract of VK1AD SOTA Activator Log: 30 June 2018 UTC Booroomba Rocks

UTC	Callsign	Band	Mode	Distance (km)	Grid Square / Notes
22:28	VK1DSH	2.3GHz	SSB	37	QF44MS DALE S59 R59
22:30	VK2COW/P	2.3GHz	SSB	63	QF44OX DIMITRI S59 R59
22:32	VK1RX/P	2.3GHz	SSB	19	QF44NN AL S58 R57
22:33	VK1KW	2.3GHz	SSB	42	QF44MT ROB S59 R59
22:46	VK1KW	1240MHz	SSB	42	QF44MT ROB S59 R59
22:47	VK1MT	1240MHz	SSB	15	QF44NM MATT S59 R59
22:48	VK1DSH	1240MHz	SSB	37	QF44MS DALE S59 R58
22:50	VK1RX/P	1240MHz	SSB	19	QF44NN AL S59 R59
23:19	VK1AT/P	1240MHz	SSB	28	QF44MQ JIM S59 R59 S2S VK1/AC-040
23:27	VK1MCW/P	1240MHz	SSB	15	QF44NM BILL S59 R59 S2S VK1/AC-03

As you can see from my log extract, I qualified with a minimum of four unique callsigns on each band 23 cm (1296 MHz) and 13 cm (2.4 GHz). Furthest contact on 2.4 GHz was with Dimitri VK2COW at 63 km (39.1 miles), signal reports were excellent.

Summit to Summit (S2S) QSOs included Jim VK1AT at Mt Ainslie and Bill VK1MCW at Bullen Range.

4el 2m yagi, 23 cm transverter and an all brass 6el 23 cm yagi

13cm transverter and a 13 cm Bi-Quad antenna

SOTA – 2.4 GHz Yagi failed at Mt Tumorrama VK2/SW-027

Posted on 28/05/2018 by Andrew VK1AD

Sunday 27 May 2018 7:30 am Mt Tumorrama. My homebrew 2.4 GHz Yagi had failed at when I noticed the 2.4 GHz 2.5 watt SG-Lab transverter SWR LED had changed to RED! Hmm.. bugger that wasn’t expected.

I didn’t have time or the tools to repair the antenna so I persisted with my backup antenna a 2.4 GHz Bi-Quad (below). I was pleasantly surprised by the performance of the Bi-Quad by successfully working Al VK1RX/P for two SOTA S2S contacts at VK1/AC-023 and VK2/ST-005, Dimitris VK2COW over a 64 km path and Matt VK1MA/P S2S at Mt McDonald VK1/AC-048 along a 39 km path of multiple 1200 m ASL mountain ranges.

Back to the 2.4 GHz Yagi. Today, using a pair on 2.5 magnification glasses I took a closer look at the folded dipole assembly. This is what I found 😦

2.4 GHz folded dipole assembly

Close up – 2.4 GHz folded dipole assembly – You never know what can go wrong at SOTA summit!

Let’s crack open the soldering iron and fix that bad boy.

Wow a clean break. A stress crack between the SMA center pin and the copper dipole

Earlier photo of the assembled 2.4 GHz Yagi

Balun impedance transformer – 43 mm length of RG402

For info – 2.4 GHz Bi-Quad photo taken earlier in March 2018

March 2018 – 2.4 GHz Bi-Quad photo courtesy of VK1MIC

73, Andrew VK1AD

Phishing Attacks and Scams

Posted on 09/05/2018 by Andrew VK1AD

For the past month this blog has been under attack by phishing from *@outlook.com email accounts who masquerade as so-called interested followers. It’s a real shame criminals attack a harmless blog set up to share my experiences in the Amateur Radio, Summits on the Air Awards Program.

For the time being, and until WordPress can provide a comprehensive security option to block scammers and phishing attacks/hacks, I have been forced to remove ‘follow’, ‘comments’ and ‘like’ features offered by WordPress. The good news, while the attacks have slowed to one or two per week, I have the ability to immediately remove the offending *@outlook.com email address follower.

I wonder if WordPress have made the connection. Bloggers like me giving up on this free product and WordPress assessing the impact on their advertising income?

When will WordPress block Phishing?

73, Andrew VK1AD

Publised: 9 May 2018

Last Update: 10 May 2018

2.4 GHz Grid-pack Antenna

Posted on 05/05/2018 by Andrew VK1AD

Unboxing a new 24dB 2.4 GHz Grid Pack Antenna 😆

A little extra gain for a +200 km S2S challenge.

2.4 GHz Gridpack Antenna

SOTA – 2.4 GHz 150 km Summit to Summit

Posted on 29/04/2018 by Andrew VK1AD

Sunday 22 April 2018 -The Peak 1230 m ASL QF43NN Snowy Mountains NSW

I have organised a S2S challenge with Al VK1RX where we will attempt a 150 km path on 23cm (1296 MHz) and 13cm (2.4 GHz) at 2.5 watts SSB.

Radio Equipment:

SG-Lab 23cm and 13cm Transverters
FT-817ND
hombrew 12el 23cm Yagi
hombrew 20el 13cm Yagi
hombrew 4el 2m Yagi
8.2 Ah 4S LiFePO4 battery
2 * 1.4 metre tripods

Profile

Path – The Peak QF43NN to Spring Hill QF44VN

Video – 12 minute video starts with a couple of contacts on 2m SSB before changing to our S2S attempt on 13cm 2.4 GHz SSB. Water condensation from the fog was a major issue. The 13cm SG-Lab transverter is crudely protected by my ball cap!

The Peak trig station identified as Hudsons Peak trigonometric station

Apart from the great success in working Al VK1RX/2 on 13cm, my best contact on 2m SSB was Dave VK2DVM in Sydney over a 355 km path at 5 watts from the FT-817. I happy to call that QSO as ‘VHF DX’.

Extract of VK1AD SOTA Activator Log: 22 April 2018 – The Peak

Time	Call	Band	Mode	Notes
22:01z	VK1FXNZ	144MHz	SSB	QF44NT John s58 r58 139 km
22:06z	VK1JA	144MHz	SSB	QF44NO Jason s51 r52 114 km
22:07z	VK1KW	144MHz	SSB	QF44MT Rob s59 r57 138 km
22:09z	VK2COW	144MHz	SSB	QF44OX Dimitris s51 r51 157 km
22:11z	VK1RX/P	144MHz	SSB	Al s58 r58 S2S VK2/ST-036 150 km
22:18z	VK1MA	144MHz	SSB	Matt s58 r55 QF44MT 138 km
22:19z	VK1MT	144MHz	SSB	Matt s58 r58 QF44NM 105 km
22:26z	VK2TWR	1240MHz	SSB	QF43PL Rod s58 r57 13 km
22:28z	VK1BG	1240MHz	SSB	QF44MS Ian s58 r58 133 km
22:29z	VK1DO	1240MHz	SSB	QF44PO Chris s51 r55 114 km
22:31z	VK1MT	1240MHz	SSB	QF44NM Matt s52 r51 105 km
22:33z	VK1RX/2	1240MHz	SSB	Al s56 r56 S2S VK2/ST-036 150 km
22:37z	VK1MA	1240MHz	SSB	QF44MT Matt s51 r31 138 km
22:38z	VK1KW	1240MHz	SSB	QF44MT Rob s51 r51 138 km
22:47z	VK2DVM	144MHz	SSB	QF56OG Dave s56 r55 355 km
22:48z	VK1MIC	144MHz	SSB	Wade s58 r58 S2S VK1/AC-035 145km
23:14z	VK1RX/2	2.3GHz	SSB	Al s51 r51 S2S VK2/ST-036 150km
23:21z	VK1JA	2.3GHz	SSB	QF44NO% Jason s51 r41 114 km
23:48z	VK1RX/2	2.3GHz	SSB	Al s52 r55 S2S VK2/ST-036 150 km
00:01z	VK1RX/2	144MHz	SSB	Al s59 r59 S2S VK2/ST-036 150 km
00:06z	VK1MA	144MHz	SSB	QF44MT Matt s54 r52 138 km

11 am local time, just as the fog is starting to lift, it’s time to head back to Canberra. Next year I will visit this summit in early summer.

View from the car after leave The Peak – extinct volcano

Railway to nowhere! Disused railway between Cooma and Nimmitabel

SOTA – Mt Ginini 13cm 2.4 GHz Activation

Posted on 01/04/2018 by Andrew VK1AD

Saturday 31 March 2018, 2.4 GHz activation from Mt Ginini VK1/AC-008 1760m ASL QF44JL, Bimberi Wilderness

The VK1 SOTA 13cm group has organised 1.2 and 2.4 GHz SOTA activations of Mt Ginini VK1/AC-008, Mt Mundoonen VK2/ST-053 and Mt Stromlo VK1/AC-043. A small group of dedicated radio amateur microwave chasers have offered to take part. You can find signal report details at the bottom of this page. First are the direct RF path profiles:

23cm (1.2 GHz) and 13cm (2.4 GHz) RF path profiles:

Mt Ginini QF44JL to VK1RX at Mt Mundoonen 810m ASL, QF45ME – 82 km
Mt Ginini QF44JL to VK1ATP at Mt Stromlo 782m ASL, QF44MQ – 32 km
Mt Ginini QF44JL to VK1JA at Wanniassa QF44NO – 31 km
Mt Ginini QF44JL to VK1DSH & VK2COW both at Gundaroo QF44OX – 65 km

Path Profiles

Mt Ginini VK1/AC-008 – Mt Mundoonen VK2/ST-053

Mt Ginini to Mt Mundoonen path profile 82 km

Mt Ginini to Mt Mundoonen

Mt Ginini – Gundaroo QF44OX 65 km

Mt Ginini – Gundaroo QF44OX

Mt Ginini to Gundaroo QF44OX

Mt Ginini – Wanniassa QF44ON 31 km

Mt Ginini – Canberra QF44ON

Mt Ginini to Canberra QF44ON

Mt Ginini – Mt Stromlo QF44MQ 32 km. The blocking feature is Tidbinbilla Mountain Range. This may help to explain the signal attenuation between Mt Ginini and Mt Stromlo. A knife-edge path over Tidbinbilla Mountain is possible.

Mt Ginini to Mt Stromlo QF44MQ profile

Mt Ginini to Mt Stromlo QF44MQ

Equipment:

Yaesu FT-817ND
SG-Lab 23cm transverter
SG-Lab 13cm transverter
12el 23cm Yagi
20el 13cm Yagi
3el 2m Yagi
Yaesu FT60R HT
8.4Ah 4S LiFePO4 battery
12 volt 4-way PowerPole distribution box
2 * 1.4 metre tripods
Assorted cables, RG-402 and LMR-195
Prismatic Compass for Yagi bearings
7 metre telescopic pole
Pole guy kit
HF linked inverted V antenna
Food and water

I qualified on 2m, 23cm and 13 cm bands with at least four unique callsigns worked on each band. Signal reports on 23 and 13cm exceeded expectations. Very happy with the outcome. The 13cm group VK1DSH, VK2COW, VK1JA, VK1RX and VK1AD experimented with SSB and FM voice modes.

What’s next? Find two or more summits each 100 km apart. 🙂

Extract of VK1AD SOTA S2S Log: 30 March 2018 (UTC) Mount Ginini

Time	Call	Band	Mode	Notes
21:07z	VK1JA	144MHz	SSB	Jason s59 r59 Canberra
21:08z	VK2DVM	144MHz	SSB	Dave s59 r58 Sydney
21:09z	VK2COW/P	144MHz	SSB	Dimitris s59 r59 QF44OX
21:11z	VK1MA	144MHz	SSB	Matt s59 r59 QF44MT
21:18z	VK1RX/2	144MHz	SSB	Al s59 r59 S2S QF45ME
21:19z	VK1ATP/P	144MHz	SSB	Paul s53 r53 S2S VK1/AC-043 32 km
21:24z	VK1DSH/P	1240MHz	SSB	QF44OX Dale s59 r59 65 km
21:26z	VK1RX/2	1240MHz	SSB	Al s59 r59 S2S VK2/ST-053 82 km
21:27z	VK1MA	1240MHz	SSB	QF44MT Matt s59 r59 41 km
21:29z	VK1ATP/P	1240MHz	SSB	Paul s52 r52 S2S VK1/AC-043 32 km
21:35z	VK1KW	1240MHz	SSB	QF44MT Rob s59 r59 41 km
21:40z	VK1BG	1240MHz	SSB	QF44MS Ian s59 r59 37 km
21:49z	VK1JA	2.3GHz	SSB	QF44NO Jason s59 r59 31 km
21:51z	VK1DSH/P	2.3GHz	SSB	QF44OX Dale s59 r59 65 km
22:00z	VK1RX/2	2.3GHz	SSB	Al s58 r58 S2S VK2/ST-053 82 km
22:05z	VK2COW/P	2.3GHz	SSB	QF44OX Dimitris s59 r59 65 km
22:44z	VK1RX/2	2.3GHz	FM	Al s58 r58 S2S VK2/ST-053 82 km

2.4 GHz Yagi Testing

Posted on 18/03/2018 by Andrew VK1AD

With the 20el 2.4 GHz yagi construction complete its time to test the antenna in the real world, theoretical gain is 15dB. Just to be perfectly clear, this is not a laboratory test, I don’t have expensive test instrument gear. I have taken my gear to the summit of Mt Stromlo VK1/AC-043 and my good friend Al VK1RX has assembled his 2.4 GHz SOTA station at the summit of Mt Ainslie VK1/AC-040 14 km (8.7 miles) north of Stromlo.

My reference antenna is a tiny 2.4 GHz ‘Big Wheel’ antenna, 2 dB gain over a dipole. Al’s 13cm yagi is 24 elements while his reference antenna is a simple 13 cm half-wave dipole.

To reduce signal losses in the feedline, I have mounted the 2.4 GHz transverter close to the antenna. Feedline is a 150 mm length (6 inches) of 50 ohm RG402 coax terminated in male SMA connectors at each end.

For obvious reasons with yagi antennas pointing at each other signal reports were excellent, we each had line-of-sight to the target summit. Nevertheless we conducted experiments with our respective antennas opposed (back to back) and at right angles to each other. We each found a deep null in signal reception when my antenna was pointing due east and Al’s antenna pointing due west, a good result. 🙂

FT-817 signal report indicators are generally of use to the operator only and no one else. I honestly can’t provide reliable signal reports as one might measure using a calibrated s-meter. What I can say is using the ‘Big Wheel’ antenna Al’s received signal, with Al transmitting into a 2.4 GHz half-wave dipole, was 5-7 to 5-8 (uncalibrated) and later using the 20el Yagi Al’s indicated signal display was full scale on the 817, all signal blocks illuminated as S++ which if material on the internet is to be believed is somewhere in the order of 12 to 15 dB greater than S8. The popular myth of 6dB per signal block is just that, a myth.

Our practical test was fruitful to the point where we now have a benchmark to work with. Next our plan is to operate from two summits 50 km apart followed by a second pair 100 km apart and so on. Can we crack 150 km on 2.4 GHz with 2.5 watts?

SOTA – VK1 2.4 GHz S2S Party

Posted on 05/03/2018 by Andrew VK1AD

Sunday 4 March 2018. VK1 is holding an early morning SOTA 2.4 GHz and 1.2 GHz S2S Party with VK1 microwave activators setting up on five peaks plus Bill VK1FWBK on 2m FM. It’s 7:30 am (20:30 UTC), Wade VK1MIC and I have walked 3 km to set up two stations on the summit of Mount McDonald VK1/AC-048 789 metres ASL, grid square QF44LQ. Wade has deployed a HF + 2m station and I have set up my 1.2 and 2.4 GHz SG-Lab transverters. Liaison with local VK1 stations was planned for 146.500 FM, however due to competing SOTA chaser traffic we thought it best to move to 146.525 FM. For future microwave activations the VK1 group will liaise on 146.525 FM.

So who’s on which SOTA peak?

As mentioned Wade VK1MIC and I have chosen Mount McDonald primarily as the summit is free of trees and vertical obstructions as viewed to the north, east and south. The bulk of my fellow SOTA activators are east of Mt McDonald. I figured Mt McDonald is the best strategic option.

To my east, Bill VK1FWBK was an early riser making the top of Mt Majura with a 2m HT, Matt VK1MA has set up on Mt Stromlo VK1/AC-043, Al VK1RX is ready to go on Black Mountain VK1/AC-042 with a 24el homebrew yagi while Paul VK1ATP is assembling a 2.4 GHz Grid Pack antenna plus a Cantenna on the summit of Mt Ainslie VK1/AC-040. Mt Ainslie is 20 km east of my position at Mt McDonald.

That’s five out of six activators, who else volunteered to get out of bed at 5 am? Andrew VK1DA/2 has opted to set up on his so-called local peak, Mt Mundoonen 10 km north of Yass in the state of NSW and 54 km north of Mount McDonald. Andrew has a hombrew 2.4 GHz transverter plus a SG-Lab 1.2 GHz transverter. I have line-of-sight to Mt Mundoonen, a 2.4 GHz S2S with Andrew should be a formality.

Terrain between AC-048 and ST-053, 54 km north

So how did we go on 2.4 GHz? The group of five in Canberra; Matt, Al, Paul, Wade and myself worked each other with ease, 5-9 signal reports all round. On the other hand working Andrew VK1DA/2 at Mt Mundoonen 54 km north of Mount McDonald became a major challenge for all. Andrew was experiencing 2.4 GHz equipment problems so he set about rectifying the problem. In the meantime the group of five, including Andrew moved to 1.2 GHz, 1296.150 MHz for a second round of S2S contacts. All five summit stations worked each other with ease, 1296 MHz was a pushover.

With 1.2 GHz done and dusted, the group moved back to 2.4 GHz looking for a weak signal from Andrew at Mt Mundoonen. Finally it came, at first a weak distant voice in the noise followed by a sudden lift in signal strength for a readable report at 5-2. On Andrew’s side my SSB signal was 4-1 sufficient to confirm signal reports, exchange summit codes followed by ‘QSL’.

Success! Qualification on 1.2 GHz and 2.4 GHz plus a bonus 2m S2S with Bill VK1FWK. 🙂

Extract of VK1AD SOTA S2S Log: 3 March 2018 (UTC) Mount McDonald

Time (UTC)	Station	Summit	My Summit	Band	Mode	Distance (km)
20:39	VK1FWBK/P	Mt Majura	Mount McDonald	146MHz	FM	23
20:43	VK1RX/P	Black Mountain	Mount McDonald	2.3GHz	SSB	15
21:09	VK1MA/P	Mt Stromlo	Mount McDonald	2.3GHz	SSB	6
21:24	VK1ATP/P	Mt Ainslie	Mount McDonald	2.3GHz	SSB	20
21:34	VK1MA/P	Mt Stromlo	Mount McDonald	1240MHz	SSB	6
21:38	VK1RX/P	Black Mountain	Mount McDonald	1240MHz	SSB	15
21:43	VK1DA/2	Mt Mundoonen	Mount McDonald	1240MHz	SSB	54
21:50	VK1ATP/P	Mt Ainslie	Mount McDonald	1240MHz	SSB	20
22:23	VK1DA/2	Mt Mundoonen	Mount McDonald	2.3GHz	SSB	54

View east – sunrise from Mt McDonald

View south over Bullen Range and Namadgi National Park.

13cm Bi-Quad is facing east working stations over a short distance (20 km) to Canberra

I’m still considering the Bi-Quad mounting arrangement – for now the 2.4 GHz Bi-Quad is resting on two blocks of wood.

SG-Lab transverter IF frequency 435.150 MHz is derived from the FT817 at 500 mW. Transverter local oscillator frequency (LO) is set to 1968 MHz for 2.5 watts RF output on 2403.150 MHz.

SG-Lab 13cm 2.4 GHz transverter with a 2.4 GHz Bi-Quad resting on two small blocks of wood. Photo courtesy of Wade VK1MIC

Andrew VK1AD in his favourite position – lying in the Aussie dirt on a mountain peak 🙂

Andrew VK1AD SOTA shack. The white pole is a 2m half-wave vertical. Photo courtesy of Wade VK1MIC

23cm Bi-Quad facing north to Mt Mundoonen – signal report exchange with Andrew VK1DA/2 was 5-9

23cm 1.2 GHz Bi-Quad antenna and transverter mounted on a tripod

Post update: photo supplied by Al VK1RX of his 13cm transverter and 2.4 GHz yagi set up on Black Mountain

Photo courtesy of Al VK1RX

First published: 5 March 2018

Last Update: 6 March 2018

Antenna Project – 2.4 GHz 13cm Yagi for SOTA

Posted on 03/03/2018 by Andrew VK1AD

I recently purchased a 13cm transverter from SG-Lab. I have constructed a 13cm Bi-Quad antenna for use on local suburban SOTA summits, however I will need a high gain 2.4 GHz antenna for SOTA activations 100+ km from Canberra, but not one as bulky as a Grid-pack antenna or parabolic dish. I have decided to construct a 20 element 2.4 GHz (DL6WU format) yagi. I used VK5DJ’s Yagi Calculator software to generate yagi element dimensions, tolerance is a BIG fat Zero +/- mm. Boom material is wood 18 mm square Western Red Cedar, very stable material. When finished the boom will be coated with a generous coating of Cabothane, hard wearing waterproof clear timber varnish.

I am using the same construction technique as I did for the 12el 23cm (1296 MHz) Yagi. Reflector and driven elements are 3.1 mm aluminium rod, I have a 2 metre length on hand. Drive element material is 1.6 mm copper wire folded by hand, inside diameter is 22 mm. 🙂