SOTA – VK1AD portable 70cm update #13 – Bobbara Mountain

Sunday 10 April 2016, planned SOTA activation of Bobbara Mountain VK2/ST-044, 753 metres ASL Maidenhead Grid Locator QF45HI

Today’s plan is to activate Bobbara Mountain on 2m and 70cm SSB using a FT-857D at 45 watts on 2m and 15 watts on 70cm.  I hope to work Bernard VK3AV and Ron VK3AFW both regular SOTA chasers on HF and VHF bands.   Woke at 5 am and left home at 05:45 am for a 1 hour, 20 minute drive to Bobbara Mountain Road.  Possible SOTA Summit to Summit (S2S) contacts include Al VK1RX with plans to activate Mt Budawang 160 km north-east of Canberra, Ian VK1DI planning to activate Mt Rob Roy in Canberra’s south and Mitch VK3XDM planning an activation of Mt Macedon north of Melbourne.

Bobbara Mountain SOTA 70cm activation
Radio: Yaesu FT-857D, UHF 70cm frequencies 432.200 and 432.160 USB
Power Level: 15 watts
Antenna: 7el Yagi
Distance to Canberra GPO (VK1):  87 km (54 miles)
SOTA Alert: Yes
Date posted alert: 6 April 2016
Notice Period:  4 days
Outcome:  Qualified Bobbara Mountain on 70cm  🙂
Duration to qualify on 70cm: 24 minutes  😉
My 2016 70cm challenge: qualified 13 from 15 summits activated

Photos: © Copyright 2016 Andrew VK1AD

Weather on the summit: 20 degrees C, sunny day & light winds building to 25 km/h  🙂  Water consumption 1 litre

For directions to this summit see my post SOTA Bobbara Mountain 20 September 2014  The ascent to the summit is 158 metres over 1.1 km (0.6 mile) taking 25 minutes.


view of the summit from Bobbara Mountain Road

On the summit VK1AD SOTA shack next to Bobbara Mountain Trig.


Bobbara Mountain summit is a harsh environment with no shade and the ground is covered with a blanket of thistle weeds.


a new piece of kit, during the week I purchased a Diamond VHF/UHF duplexer.  🙂    Picture taken just after working Ron VK3AFW on 2m 144.200 MHz. Ron is located in Melbourne 483 km south-west at 231 degrees.

Started the activation as planned at 2200 UTC (8 am local) calling ‘CQ Canberra’ on 144.2 MHz.  Ian VK1BG was first respond with a strong signal on 2m. Ian offered a contact on 432.160 for my first 70cm contact over 76 km (47 miles).  Next in the VHF Dx calling group was Col VK2BCC at 190 km followed by Chris VK2DO also at 190 km.  After a successful 2m contact with Chris we moved to 70cm to complete a valid signal report exchange over 190 km (118 miles), a new SOTA 70cm distance record for me.  My PB for a 70cm contact was with Dimitris VK2COW during a recent SOTA activation of Mt Perisher.

Speaking of Dimitris, Dimitris called in for the third 70cm contact over 67 km followed by Matt VK1MA in Canberra northern suburbs and Andrew VK2UH over 58 km near Yass.

At 10 minutes before UTC day change I received an SMS from Al ‘ready on 2m’.  With our antennas set to horizontal polarisation we completed a successful 2m SSB S2S over 158 km.  We turned our attention to 70cm calling on 432.160, Al’s SMS indicated his 70cm antenna (a 1/4 wave ground plane) was set in the vertical position. I rotated the 7el Yagi to the vertical position and listened for Al’s signal.  The signal was weak and barely readable and after two failed attempts I ‘text’ Al suggesting he mount the antenna so that the radiating element is horizontal. (less attenuation of the signal)

It worked, signals went from unreadable to 5-1 where Al’s signal was now above the local noise floor.   Thanks Al for persisting with the 70cm contact.  We now have a 70cm S2S record completed over 160 km.  Check out the photo supplied by Al of his 70cm ground plane mounted on the squid pole in the horizontal position.  A lesson learned, horizontal polarisation is king for successful signal report exchanges involving VHF/UHF weak signals in the terrestrial-landscape.

On 2m 144 MHz, I achieved my goal of working SOTA chasers Bernard over 438 km and Ron at 483 km in Melbourne’s southern suburbs. Today’s 2m long distant contact was with Michael VK3KH over 507 km (315 miles) to Mount Eliza, signal reports were 5-5 and 5-1.  Plenty of noteable 2m VHF Dxers in the log including Col VK2BCC, Greg VK1AI, Gordon VK3EJ, David VK2AUU, Russ VK2BJP and John VK2YW.  Missing from today’s activity was Rob VK1KW, I can’t work out why I missed Rob?

Extract from VK1AD SOTA Activator Log – Bobbara Mountain on 70cm and 2m bands

Time Call Band Mode Notes
22:01z VK1BG 144MHz SSB Ian S59 R58 QF44MS 76 km
22:03z VK1BG 433MHz SSB Ian S58 R57 QF44MS 76 km
22:11z VK2BCC 144MHz SSB Col S51 R55 QF56DI 190 km
22:14z VK2DO 144MHz SSB Chris S57 R57 QF54CH 190 km (118 miles)
22:14z VK2DO 433MHz SSB Chris S52 R53 QF54CH 190 km
22:16z VK2COW 433MHz SSB Dimitris S51 R51 QF44OX 67 km
22:18z VK2COW 144MHz SSB Dimitris S55 R55 QF44OX 67 km
22:20z VK1AI 144MHz SSB Greg S59 R59 QF44MP 87 km
22:24z VK1MA 144MHz SSB Matt S59 R59
22:27z VK1MA 433MHz SSB Matt S55 R55
22:34z VK3EJ 144MHz SSB Gordon S59 R59 QF24TB 307 km
22:35z VK3AV 144MHz SSB Bernard S51 R31 QF22PL 438 km (272 miles)
22:45z VK2UH 433MHz SSB Andrew S59 R59 QF45LD 58 km
22:46z VK2UH 144MHz SSB Andrew S59 R59 QF45LD 58 km
22:52z VK3AFW 144MHz SSB Ron S51 R51 QF22MC 483 km
23:06z VK2NSS 144MHz SSB Steve S59 R59 QF45MA 55 km
23:09z VK2BJP 144MHz SSB Russ S55 R55 QF33KW 223 km  (138 miles)
23:11z VK3AUU 144MHz SSB David S55 R52 QF21WU 460 km (285 miles)
23:15z VK3KH 144MHz SSB Michael S55 R51 QF21MT 507 km (315 miles)
23:24z VK2YW 144MHz SSB John S55 R53 QF34QU 126 km
23:53z VK1RX/2 144MHz SSB Al S2S VK2/ST-015 S55 R55 QF44XM 158 km (98 miles)
00:01z VK1RX/2 433MHz SSB Al S2S VK2/ST-015 S51 R51 QF44XM 158 km on 432.200

The next two photos are from Al VK1RX showing his 2m and 70cm antennas set up at Mt Buddawang 158 km (98 miles) north-east of Bobbara Mountain!

Al's 2m dipole at Mt Budawang. That's string on the ends of each element

Al’s 2m horizontal dipole at Mt Budawang. That’s string on the ends of each element.  (photo kindly supplied by AL VK1RX)

Al’s 70cm ground plane mounted in the ‘horizontal’ position

VK1RX 70 cm ground plane at Mt Budawang

VK1RX 70cm ground plane (photo kindly supplied by Al VK1RX)

View north from the summit of Bobbara Mountain


view below the summit – my car on Bobbara Mountain road (center of the picture)


Bobbara Mountain Trig supporting the HF antenna, wind is from the south at about 20 km/h.  Sooo many thistle weeds and for protection I remembered to wear my gaiters.  🙂


Bobbara Trig – ‘BOBBARA’ Geodetic Station Plate

Extract from VK1AD SOTA Activator Log – Bobbara Mountain on 20m, 30m and 40m HF bands

After wrapping up the VHF Dx session I raised the HF linked dipole antenna for operations on 40, 20 and 30m.  27 chasers on 40m, including summit to summit contacts with Al VK1RX/2, Mitch VK3XDM/P, Ian VK1DI/P and Phil VK2HPN/1 activating Isaacs Ridge also in Canberra’s south.

Apart from the excellent long distance contacts on 2m SSB, another big surprise was working Mike VK6MB on 7.100 MHz over 2970 km with signal reports exchanged at 5-1, a rare contact on 40m!  I moved to 14.310 MHz hoping to work Mike for a second time on 20m and we did, with signal reports at 5-8 and 5-7.  🙂

The last few chasers to wrap-up 3 hours on the summit included a 2m S2S contact with Phil VK2HPN on 146.5 FM followed by a move to 10.130 MHz to work Matt VK1MA and Nev VK5WG.  Nev was experimenting with QRP power levels operating a FT-817 into his HF dipole.  I matched the FT-857Ds output power to Nev’s at 5 watts.  We complete a QRP 5 watt exchange with signal reports 5-7 each way.  Good work Nev 😉

Time Call Band Mode Notes
00:12z VK1RX/2 7MHz SSB Al S2S VK2/ST-015 S59 R59
00:13z VK3XDM/P 7MHz SSB Mitch S2S VK3/VC-007 S59 R58
00:16z VK2IO 7MHz SSB Gerard S59 R59
00:19z VK2HPN/1 7MHz SSB Phil S2S VK1/AC-041 S59 R59
00:20z VK2NP 7MHz SSB Cliff S58 R56
00:21z VK3PF 7MHz SSB Peter S59 R58
00:22z VK3PMG 7MHz SSB Mick S59 R59
00:23z VK5IS 7MHz SSB Ian S59 R57
00:23z VK5PAS 7MHz SSB Paul S59 R57
00:24z VK5WG 7MHz SSB Nev S59 R56
00:24z VK3CAT 7MHz SSB Tony S59 R59
00:25z VK3LED 7MHz SSB Col S59 R59
00:25z VK3AV 7MHz SSB Bernard S59 R59
00:26z VK3ZPF 7MHz SSB Peter S59 R57
00:29z VK1EM 7MHz SSB Mark S59 R59
00:30z VK7CW 7MHz SSB Steve S59 R59
00:30z VK3HN 7MHz SSB Paul S59 R59
00:31z VK1DI/P 7MHz SSB Ian S2S VK1/AC-031 S59 R58
00:32z VK3FABT 7MHz SSB Allen S59 R58
00:33z VK2YK 7MHz SSB Adam S59 R59
00:34z VK3MEG 7MHz SSB Steve S59 R59
00:34z VK3DAC 7MHz SSB Fred S59 R59
00:35z VK3MIJ 7MHz SSB David S59 R59
00:36z VK4AAC/3 7MHz SSB Rob S59 R59 VKFF-0959
00:37z VK5FANA 7MHz SSB Adrian S53 R51
00:38z VK2HBG/P 7MHz SSB Gerald S59 R53 Mogood VKFF-0032
00:41z VK6MB 7MHz SSB Mike S51 R51 QF85BS 2967 km awesome
00:52z VK6MB 14MHz SSB Mike S58 R57 QF85BS 2967 km
00:58z VK2HPN/2 144MHz FM Phil S2S VK1/AC-041 S51 R55
01:01z VK1MA 144MHz FM Matt S59 R59
01:05z VK1MA 10MHz SSB Matt S51 R31
01:06z VK5WG 10MHz SSB Nev S59 R57
01:08z VK5WG 10MHz SSB Nev QRP 5 watts S57 R57 and me also 5 watts

My SOTA VHF and UHF distance records
Today I set a new PB 432 MHz distance record which now stands at 190 km from a contact with Chris VK2DO.
My 144 MHz record stands at 560 km, a contact made with Ian VK3AXH on Monday 28 March 2106 from Mt Mundoonen.
My 432 MHz summit to summit record is shared with Al VK1RX at 158 km between Bobbara Mountain and Mt Budawang.
My 144 MHz summit to summit record is shared with Allen VK3ARH at 495 km between Mt Ginini and Mt Beckworth.
My 50 MHz record stands at 2343 km, a contact made with Simon ZL1SWW on Saturday 9 January 2016 from Yellow Rabbit Hill



2 thoughts on “SOTA – VK1AD portable 70cm update #13 – Bobbara Mountain

  1. Some good PB’s in there! I don’t think I’ve ever used SSB on 2m/70cm! I’d be interested to know how you go about finding the owners of the property to gain access?


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