AM for fun – SOTA on Bulgo Hill 1/4/2015

Bulgo Hill VK2/IL-017 Royal National Park VKFF-435 293m 1pt

a call to AMs

Andrew VK1DA proposed using AM for a bit of fun as this mode is rarely used by SOTA operators, and also to prepare for upcoming ANZAC celebrations. I only use AM for tuning up – never for QSOs on a summit. It was time to change all that. My expectations weren’t high as Amplitude Modulation has nowhere near the penetrating power of single sideband, and with low power thrown into the mix, it reduced the range even more. The proposed outing was timed to be an “after work” activity. This time of day sees very good propagation on 40m, the main target band, so this would work in our favour.


The day before, SOTAwatch alerts were up from Andrew VK1DA and Andrew VK1NAM as well as Adan VK1FJAW. The weather was looking good so I thought I might as well join in. Chose to return to Bulgo Hill for my second activation of this peak. After all, there were some summit-to-summits in the offing! Access to Bulgo Hill was as per my previous activation. Last time I used 4 guy ropes to hold up the squid pole which was somewhat time consuming to set up. This time I spent more time looking around for a supportive tree – and I found one. There was foliage hanging down over the top, but it was high enough to not cause too much obstruction. In any case the antenna was at least 8m high which is fine. I also set it up perpendicular to the track where last time the antenna ran along it. This does mean diving into the bush with the antenna ends, but the better signals should make that worth while.

Antenna and shack on Bulgo Hill at sunset

Antenna and shack on Bulgo Hill at sunset


Once set up I started calling on 6m SSB hoping for a summit-to-summit with VK1NAM, but there were no takers. Then I tried 10m AM and SSB but nothing was heard. After about 10 minutes with some SMS exchanges with Andrew, switched to 40m AM, set the KX3 to 12 Watts and started calling. The power meter read about 5 Watts when unmodulated and kicked up to around 8W when I started yakking. The mic gain was left at the same level as for SSB and the speech processor was on as usual. There was a LSB station 5 kHz down the band and nothing nearby up the band so plenty of bandwidth for operating on AM.

Spotted myself on SOTAwatch on 40m and first cab off the rank was Andrew VK1NAM with the first of the summit-to-summit contacts, this one from Mt Stromlo VK1/AC-043. After 20 minutes and 17 chaser contacts, Andrew VK1DA came on for the second S2S. He was on Black Mountain VK1/AC-042. Read his full report here. Five minutes later, Adan VK1FJAW called in from Mt Taylor VK1/AC-037 completing the trifecta. There were two more chasers after that bringing the total to 19 AM contacts on 40m from call areas VK1,2,3,4 and 5. That was definitely better than expected! Audio was generally good with the usual selective fading typical of AM on HF. Some of the weaker signals sounded a little weird and modulation level varied but was usually fine. The summit is at least 1km from the nearest power line so QRM wasn’t an issue. The only competition was band noise, and that wasn’t excessive.

Radio "shack" on Bulgo Hill

Radio “shack” on Bulgo Hill


With no more AM chasers I switched to CW on 40m and racked up 4 contacts. It was getting dark but I wanted to keep going. I put on the head torch, spotted myself on 20m and started calling there and made 7 contacts into EU. At 7:10pm with just moonlight left, I pulled the plug and closed down. Walking the 1.5km back to the car via moonlight with not a breath of wind was magical. And what a great activation. Using AM really was a lot of fun!

Association Manager alert – some might say an Activation Moan 🙂

Before visiting the summit I looked into the exact location of the peak as last year there had been discussion that the coordinate was out, and I had found that to be so myself. Using google Earth I was able to create a plot of the activation zone and locate the peak. Accordingly, it shows the summit at coordinate (-34.1922, 151.0297) with 293m elevation. This is a departure from the position on SOTAwatch of (-34.1916, 151.0307) at 300m. On google earth the elevation here is 7m lower at only 286m. it is still well within the activation zone. The image shows yellow pins at the 2 positions. At the peak I checked my coordinate before activating and it was close to the one from google Earth. At some point, the values on SOTAwatch should be reviewed.

Bulgo Hill activation zone, peak, SOTAwatch peak and carpark

Bulgo Hill activation zone, peak, SOTAwatch peak and carpark


30 successful contacts (mostly on AM) and 3 S2S in under 70 mins made for a really enjoyable activation and proved that AM mode need not be feared. Thanks chasers and activators! You could say it was AMazing!

‘AM gear

Elecraft KX3 @ 12W powered by 4200 mAh LiFePO4 battery.
ZS6BKW antenna at 8m on 10m squid pole.


Date:01/Apr/2015 Summit:VK2/IL-017 (Bulgo Hill) Call Used:VK2IO/P Points: 1 Bonus: 0

Time Call Band Mode Notes
06:59z VK1NAM/P 7MHz AM R58 S57 7180 Andrew VK1/AC-043
07:02z VK2YW 7MHz AM R59 S59 7180 John
07:06z VK2JMW 7MHz AM R57 S59 7180 Ian
07:06z VK3BHR 7MHz AM R55 S55 7180 Phil
07:08z VK3FQSO 7MHz AM R44 S54 7180 Amanda
07:08z VK3DBP/2 7MHz AM R59 S57 7180 Paul in Batemans Bay
07:09z VK4JD 7MHz AM R49 S59 7180 Peter
07:10z VK1MA 7MHz AM R59 S57 7180 Matt
07:11z VK3DAC 7MHz AM R57 S55 7180 Fred
07:12z VK1ATP 7MHz AM R59 S56 7180 Paul
07:13z VK5WG 7MHz AM R42 S56 7180 Nev
07:15z VK5IS 7MHz AM R55 S55 7180 Ian
07:15z VK3PF 7MHz AM R44 S56 7180 Peter
07:16z VK1EM 7MHz AM R45 S58 7180 Mark
07:17z VK1DA/P 7MHz AM R59 S58 7180 Andrew VK1/AC-042
07:21z VK2LEE 7MHz AM R59+10 S59+10 7180 Lee
07:23z VK1FJAW/P 7MHz AM R59 S57 7180 Adan VK1/AC-037
07:27z VK3ARR 7MHz AM R54 S57 7180 Andrew
07:30z VK2VK 7MHz AM R55 S59 7180 Russell
07:42z VK3CAT/P 7MHz CW R579 S599 7032 Tony
07:44z VK2AFA 7MHz CW R599 S599 7032 Sam
07:45z VK2GDI 7MHz CW R599 S599 7032 Ian
07:49z VK3RY 7MHz CW R599 S599 7032 Helen
07:54z CU3AA 14MHz CW R559 S559 14062 Joao
07:56z ON4FI 14MHz CW R539 S559 14062 Karel
08:01z DJ5AV 14MHz CW R529 S539 14063 Michael
08:02z DK4RM 14MHz CW R559 S559 14063 Xaver
08:05z OK2QA 14MHz CW R339 S559 14063 Ruda
08:06z DL1ASF 14MHz CW R559 S559 14063 Klaus
08:08z DL3JPN 14MHz CW R539 S559 14063 Steffen