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.
The 2.4 GHz transverter has been completed and I used it in the vhf/uhf field day on the weekend of 15/16 November.
Construction began on Sunday 9 November with the first components soldered onto the sequencer board, finishing on Friday 14th November when I finally measured the transmitter output power.
The next day I was on Mt Ginini, with a 24 db gridpack dish (obtained from The RF Shop) attached to the transverter, receiving a big signal from Ted VK1BL at Mt Coree. I replied to his call and asked how he was hearing me. He replied immediately! This was my first contact on 2.4 GHz, made all the sweeter by the knowledge that the transverter was home made.
Together with some other “firsts” on this field day, it made for a very good weekend.
I have written up the details of the design and construction and submitted it as an article for AR magazine. The article was published in July 2009 and can be found in the AR archives here.
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.
The equipment was set up and taken down each day as I was not able to stay overnight. The morning temperature on Sunday was about 5 which was much warmer than it could have been. Some contacts into Sydney on 2m and 70cm, with an attempted contact on 23cm with Adrian VK2FZ. Contacts made around town on all bands and a visit from Ian VK1FOTO (later VK1IS), John VK1JST and Charles VK1CM. Power was from the GMC 950va alternator.