Tag Archives: vhf/uhf

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.

Preparing for spring VHF/UHF field day, November 15/16

This week’s project is to prepare for next weekend’s VHF/UHF field day.

I plan to operate from a mountain southwest of Canberra, with equipment for 50, 144, 432, 1296, 2403 and 10368 MHz.  The first four bands are bands I have used before but the last two are new for my station.  The 2403 equipment will be a simple transverter driven by a FT290R radio on 144.  The antenna for that band will be a grid type dish.

The 10368 MHz equipment has been borrowed from another local amateur.  It is a transverter driven by an Icom IC202 on 144, the antenna is a dish.  It all mounts on a tripod which readily allows azimuth and elevation adjustements.

On all bands the main mode used will be voice, using upper sideband.  For some contacts with more distant stations, morse (CW) will be used as it is much easier to hear weak morse signals than weak voices.