Tag Archives: vhf/uhf

VHF/UHF Field day/contest Jan 14/15 2017

The VHF/UHF field day in January is one of my favourite events.  I have had some great surprises on these weekends.  I had no idea what to expect this time, though the weather was forecast as damp on Saturday and dry on Sunday.

I arrived on site around 6pm Friday night.  Along the route from Yass via the Mountain Creek Road I had noticed a lot of debris on the road, including some tree branches that had been broken off by high winds.  I didn’t realise a storm had gone through Canberra while I was driving to Mt Ginini, breaking trees and strewing debris all over suburban streets and bringing trees down over some of the arterial roads, leaving damage that would be visible for weeks afterwards.

This is how far I got setting up on Friday night. After this, the wind came up and the rain and sleet started.

The weather at the time was windy and when I tried to set up the tent it was clear that it would not survive that wind.  In the hope that it would clear away in a few hours, I decided to sit it out and stayed in the car.  By 9pm it was dark and I had to decide whether to  re-pack my tent and go back to Canberra for the night or hang on.  I decided to hang on.  It rained quite heavily for a while and the wind kept howling so once it was really dark, I felt there was no other option.

In the early morning it seemed to be better.  The wind was still there but didn’t seem so bad.  The rain had cleared.  But I hadn’t slept much.

I set about the job of assembling the antennas, the tent, the interconnections and generator.  By 12 noon, the contest start time, I was just about ready to roll.

432 MHz preamp cabling
144 MHz antenna
1296 MHz antenna – end mounted

 

The erected antennas looked very much like they have for the last 10 years so I didn’t take any new photos of them. The 2m, ;70cm and 23cm yagis on one mast and the 6m 3el yagi on another, both rotated from the base using KR400 rotators.  Feedlines: RG9B for 2m, CNT400 for 70cm and 23cm, RG213 or similar for 6m.

Here’s a pic of the antennas from a previous operation at Ginini.  A few configuration differences for the 70cm antenna but otherwise very similar this time.

VHF/UHF antennas on Mt Ginini

 

Once I got on the air, I found beacons from VK3 were very low, the Sydney beacons were almost undetectable and few portables outside the VK1 area.  Only VK2IO was heard initially, but one or two others did emerge later in the weekend.  VK1DSH, VK1RX, VK1RW, VK1MT and VK1AI were all out in the field, most of them on 50/144/432 and Dale was on 1296 as well.  We had a small number of home stations operating the bands too.

After working Gerard VK2IO (Mt Bindo near Oberon) I then worked Phil VK5AKK on both 144 and 432.  We tried 1296 too, but although I could hear a signal from his 100w, my 10w was too far down to make it a two way contact.  A digital mode would have worked.  hmm.  More power on my end would have helped too.  Double hmm.

The day progressed without any more surprising dx, and I found it hard to convince myself to stay awake after 9pm, having got very little sleep in the driver’s seat of the car on Friday night.

At 5:30 in the morning, there were good signals from the vk3 beacons, Sydney was a bit better too.  And I had a very good signal from the Mt Gambier beacon on 144.550 plus a weak signal from Mt Lofty on 144.450.  I hoped this indicated something of the contacts to be made in the following hours.

It did, partly.  VK5DK at Mt Gambier was worked, as was VK5PJ.  But conditions were not good enough to give us contacts on higher frequencies.

My surprise contact on Sunday morning was being called by Mike VK3BDL/7 at Flinders Island.  After working me on 144 and 432, Mike went on to work Chris VK2DO at Batemans Bay on 144, a contact which they were both very happy with.

Eventually the contest ended and I followed it up with a short period of activating Mt Ginini as a SOTA station, using the IC703 running from a LiFePO4 battery.  I had at 6am set up the 20m vertical in the hope of making an S2S with a US station who was looking for VK contacts.  I may have been a bit unlucky with conditions, or jut not spending enough time listening for the US signals.  No luck with S2S but did have a good contact with home station NS7P on CW.

The packing process took about 4 hours and I left the summit at 5pm.  A 2 hour trip back to Yass and a welcome shower and a cold drink when I got there.

The 6m beam seen in the foreground (in the shade, sorry) travels in a partially assembled state. The gamma match stays in place, but the extensions just come out of each element and it then is not much wider than the 2m beam and is narrow enough to be carried quite safely on the roof rack of the car.

Mostly packed up and ready to be loaded into the car and trailer. 2m and 70cm mast still to be disassembled.

 

Contacts made:  183 total.

Band totals:

  • 50 Mhz:  39
  • 144:   70
  • 432:  51
  • 1296: 22

Total points claimed under distance calculation rules: 55916

Points lost due to a wrong grid locator:  about 10.

Points lost due to not enough other portables:  500,000.

haha

 

VHF/UHF Field day (contests) scoring proposal

After discussion for several months a proposal has been published for revision of the scoring rules for Australian/WIA-sponsored VHF/UHF Field Day contests.

The proposal is here:  vk1da.net/vhffielddayrules.html

A survey of active VHF/UHF amateurs seeking views on the proposal and other aspects of these events is here:  vk1da.net/survey/index.php

The proposal was developed by a group of interested radio amateurs, primarily Colin VK5DK and myself but in consultation with a number of others.

2010 Spring VHF/UHF Field day on 7 bands

For this event I took my usual station on 50 to 1296 MHz, plus my transverter and gridpack for 2403 MHz, Ted VK1BL’s transverter and gridpack for 3400 and Dale VK1DSH’s 10 GHz station (IC202, transverter, dish and tripod).

Contacts were made on all these bands.

Performance of the station on 1296 MHz was not as good as in previous years.  This may be due to conditions, or to a problem with my antenna or my location on Mt Ginini.  It is becoming increasingly more difficult to find suitable places where even two required directions are not partly blocked by the trees on that mountain.

Some pictures are already on http://www.flickr.com/photos/exposite/sets and I’ll be putting some also onto the vk1da.net photo pages.

Joining VK9NA VHF/UHF dxpedition to Norfolk Island

I am joining the VK9NA team for January 2011. All the details of this expedition are on the VK9NA.COM website. This is a VHF/UHF/microwave expedition which will include some 2m EME capability and will have reasonable power (75w) on 5.7 and 10 GHz too.

The station should be on the air by 9th January and will be active in the following weekend’s VK VHF/UHF Summer Field Day event.

More details on the VK9NA website vk9na.com

Summer 2010 VHF/UHF Field Day

The January 2010 event was much more successful for me than the Spring field day about 6 weeks earlier.

This time Dale VK1DSH and I operated as a multiop station on 50, 144, 432, 1296, 2403 and 10368 MHz.

Successes:

  • Dale made several contacts on 10 GHz with Andy VK2AES operating south east of Bungendore.
  • Despite leaving the feed for the 2.4 GHz dish at home, we still made a contact with Andy on that band, using a “field day special” feed constructed onsite from a piece of wire and a N type socket connected to a piece of cable through the dish centre and attached to the normal feed hardware.  Signals S9 over the 70 or 80 km path.
  • Several successful contacts with Dave VK2JDS near Bathurst on 1296 MHz. Some persistence was needed for the first contact, when conditions were not so good and we had to get our beam headings right.  More power at both ends would have been a help.
  • Other than that, we had a fair contact rate on 144 with many throws to other bands.
  • For this event I used one of Owen VK1OD’s Roger Beep boards.  I assembled the board on the previous weekend, mounting the board into a small box with the Icom mike plugging into a socket on the RB box, and mike output to the IC910 through a short section of shielded cable. I set the CW speed to 30 wpm and selected the K option.
  • Despite some thunderstorm activity in the area, we didn’t have to shut down.

Activity was a little lower than in the past.  Chris VK2DO was away on a business trip and Matt VK2DAG was roving up and down the NSW coast and unfortunately we didn’t work him once. Our score was just over 2000 points, though, with the help of the additional microwave bands. We were grateful for Andy VK2AES’s efforts in going portable on both days and giving us contacts on all bands, in particular 2.4 and 10 GHz.

New antennas for 1296 MHz

I received the two 18 element yagis for 1296 Mhz and they appear to be strongly made. We will see whether they are any better than the previous antenna.  I have borrowed a splitter for them and will use that for the Summer field day in mid January, unless I can make my own before then.

I found a website offering data on stacking distances for yagis.  For a boom length of 1.5m on this frequency the stacking distance recommended is 2.4 wavelengths, which works out at 55cm (23cm wavelength).  The feedlines on the yagis are about 25 cm long but that’s not long enough to reach the power divider, so additional connectors and cable will be needed, eating into the stacking gain.

Next step for 23cm is to configure the power amplifier so it can be operated remotely from the tent.  I read some comments on the UK microwave reflector about power levels from IC910H not being up to the 10w level expected.  Time to get out the power meter and check mine out.