The K-index quantifies disturbances in the horizontal component of earth’s magnetic field with an integer in the range 0–9, with 1 being calm and 5 or more indicating a geomagnetic storm. Rising K-index results in a higher noise level, mainly below 10 MHz. A high noise level on 40 m does not imply a high noise level on 20 m.
The Solar Flux Index (SFI) is an indication of the degree of ionization in the higher stratospheric regions. Higher SFI values favor good propagation conditions on the amateur radio bands 20 m and above.
A special case is the 30 m band: both, SFI and K-index can have an impact on the propagation on this band. It is actually a good band in times of the solar minimum as well as the solar maximum.
Best time to operate on HF is after a solar flare eruption. As soon as the solar storm declines, the noise on the bands decreases, combined with an increase of the maximum usable frequency MUF. This often last until sunset. Propagation conditions on 40 and 80 m in the following night could be excellent. On the following day the MUF still can be raised, good for propagation on the higher HF bands.
In addition – after a solar storm – the magnetic disturbance is often very low, a good opportunity to work on 40, 80 and 160 m with low noise.
In order to improve the coverage of our SARTS VHF repeater and sort out technical problems, it is very helpful to have a list of practical issues experienced during operation. Therefore, please help and report any problem using either this Github link, or our contact form.
Please state your call sign, the power and antenna used with the description of the issue and date/time, when it appeared.
On Sunday, 15 November SARTS will be conducting a test of a potential new VHF and UHF repeater site. We are looking for volunteers in all parts of Singapore to assist us with signal reports and two-way contacts. If you are available, please meet us on 145.550 MHz between 3:00 pm and 3:15 pm, and on 433.625 MHz from 3:15 pm – 3:30 pm local time.
The SARTS rig survey is now available for download. This is the joint work of 9V1AS, 9V1YC, 9V1KB, 9V1CL and 9V1MH. Special thanks to Matt, 9V1MH for creating this final version of the spreadsheet and for adding current models which have a good chance of approval.
Despite our best efforts, amateur radio equipment approval in Singapore is still on an individual, case by case basis. IMDA’s criteria is not public information, and what you see in the spreadsheet was gathered by surveying our members. This gives us a good picture of which rigs have been approved in the past.
As of January 2020 we know that 65-137 MHz is a sensitive, no-go area. Avoid submitting equipment which can receive in this band. Prior to January 2020 only the 108-137 MHz was strictly off limits, but this seems to have been expanded recently.
Please note that this is only a survey. Just because another 9V1’s rig has been “IMDA approved” in the past is no guarantee that yours will be too.
From Saturday, October 26, 00:00 UTC (08:00 SGT) to Sunday, October 27, 23:59 UTC (Mon, 08:00 SGT) the 2019 CQ World-Wide DX Contest took place. It is one of the biggest international contests during the year.
The objective for amateurs around the world is to contact as many CQ zones and countries as possible. Contest exchange is RS report plus CQ Zone number (28 for Singapore).
Following SARTS members participated in the contest:
9V1YC 9V1BH 9V1HY
M-1: Multi OP High power, Single transmitter, SOL40: Single OP Low power 40m, SOLA: Single OP Low power, all bands.
Raw scores will be published on the CQWW web site. Thanks to all OPs for the activity!
I’m so glad we made JOTA SG 2019 a dream come true. We managed to bring the radio aspect back into Scouts SG. The last one was back in 2001, I guess? We were only given 3 hours, and we made the best out of it.
The event was ran by a group of super enthusiast hams, each to their own merits! Even the XYLs (wives) lend a hand to make this a wonderful one.
We made sure the scouts get full engagement and exposure during the activities, as you can see they are the ones holding the radio most of the time.