Tag Archives: 23cm

SOTA on 23cm, 23 March 2019

In keeping with the trend for activity days that match the band with the day of the month, a 23 cm activity day in and near vk1 on the 23rd of March was organised for SOTA operators by Andrew VK1AD.

I operated from Mt Mundoonen, which is near Yass.

The antenna for 23cm was a 4 element yagi mounted on a camera tripod as seen in the featured photo above.

The weather conditions were misty at 8am, but it cleared up later.

The operating position for this activation was from inside a sun shelter, a small 3 sided tent structure that I find helps a lot to reduce sun and wind exposure and is also useful in rain.

The sun shelter protected the operator from sun and wind. This shows the 23cm yagi near a half wave vertical for 2m fm.

I was impressed by the signals received on the 2m dipole. The beacon from Sydney VK2RSY was good copy and I heard the VK3RGL beacon from near Geelong at a low level. Surprising to hear it on such a low gain antenna. Zero db above a dipole…

[edited following comment about reception on the 2m dipole] A note on the dipole: Testing the 2m dipole antenna for SWR while mounted at about 4m elevation, offset about 2m from my metal clad shed at home, I noted a significant change in impedance depending on whether the dipole was end on to the shed, or aligned broadside to the shed. Clearly a 2m offset from the shed is insufficient for there to be no interaction, so you wonder what is the effect on each antenna when you see antennas mounted on cars, with spacing of several inches only between antennas for various bands.

Edit: checking image links

VK1 SOTA 2nd anniversary 1st Feb 2015 at Mt Stromlo

In 2014 the VK1 SOTA group proposed a BBQ and joint activation at Mt Stromlo on 1st Feb, to celebrate the first anniversary of SOTA in VK1.  On the day the weather was very hot and the event was called off.

This year the group again decided to have a BBQ at Mt Stromlo, with a joint activation to provide contacts with the summit.  The plan was to have either a lunch or evening BBQ and set up a few antennas to allow the group to make radio contacts.

Towards the weekend, it was clear the weather this year was not going to be hot, instead it was likely to rain during the afternoon.  Several of the group were unable to make it due to conflicting social engagements so the remaining hopefuls decided to make it a 4pm start and hope for the best re the weather.  That turned out to be a mistake as the weather was moderately clear during the day but towards 4pm it looked more like rain every minute.

23cm band

I had borrowed a 23cm fm mobile rig from Compton VK2HRX who was keen to get chaser points for 23cm and was visiting Canberra that day.  So I wanted to make at least a few contacts on 2m FM and on 23cm FM. On 23cm the simplex frequency is 1294.0 MHz.

I arrived on the mountain earlier than 4pm and spoke with Paul VK1ATP on 2m FM soon after.  Simon VK1FAAS emailed the VK1 SOTA group suggesting it looked like a cancellation was going to be necessary and I agreed with that as the weather certainly did not support the event we had hoped for.  However after some initial thunder and rain visible to the south, it appeared that the main body of rain had passed us by, so I decided to set up the 23cm antenna and the borrowed 23cm fm radio. Paul had arrived on summit by then and was able to observe the 23cm contacts.

After making 3 contacts on 23cm I was looking for a 4th contact so as to qualify the summit on that band.  I monitored 2m fm in the hope that someone would call me there offering a contact on 23cm.

HF contacts

With the rain apparently having passed and no apparent imminent thunderstorm, I decided to put up the HF antenna and see how badly the bands were affected by the nearby storms.  At this point Paul was tempted to do likewise, but after considering his wife and kids he decided against this and departed, wishing me well on HF.

Once I got the antenna up, 40m sounded ok and after I fixed my antenna (again), prompted by Matt 1MA who thought I was not strong enough at his location about 10 km away, I made 19 contacts on 40m including an S2S (summit to summit) contact with Kevin VK3KAB and Glenn VK3YY.  During this period the rain started in earnest and I covered myself as well as the radios with a second tarp.  Weird sitting in the rain under tarps talking on the radio.  Why didn’t I take a tent…

The radios under the tarp.  The logbook with wet pages.  It was only just legible the next day for typing up the log. Radios under the tarp

20m and 12m, ssb and cw

Running out of contacts on 40m I then decided to look at 20m and higher bands.  At this point I also decided to send an email to the VK1 mailing list asking (begging) for anyone with 23cm gear to call me on 146.5 as I wanted a 4th contact on 23cm.

Having moved the HF antenna to 20m by disconnecting the two links I spotted myself on 14.310 and called cq, which resulted in 3 contacts into South Australia (VK5).  I did not receive further replies so I looked higher in frequency.  On 24.9 MHz I heard a strong KH6 (Hawaii) calling CQ on CW and I thought I should at least try a contact.  I received a good (579) report from the KH6 which was great as the antenna was still linked for 20m.

The 4th contact on 23cm

Before finishing the KH6 contact I heard Jayson VK1JA calling me on 2m fm.  I asked him to stand by a minute while I completed with the KH6.  When I went back to Jayson he said he was receiving me well and wanted to try 23cm.  We then made a good contact over about 15km to his location in Tuggeranong.

After completing with Jayson I removed the 12m link on the HF antenna and made another contact on 24.9 MHz CW with a Japanese station.  These dx contacts were completely unspotted as I was answering their CQs. Their power levels were most likely at least 100 watts or 10 db more than my IC703’s 10 watts, and possibly even higher.

As an anniversary event it was a fizzer but I got some satisfaction from making the 4 contacts on 23cm and handing out some points to SOTA chasers.  Also gained some S2S points from working VK3KAB and VK3YY.