Postings

Experiences with SDRs and active antennas

9V1KG, Klaus, Feb 2021

The presentation gives an overview on SDRs under $ 200 and active antennas for the HF range, and how to setup a simple and low budget SWL and monitoring station.

SDR-PresentationDownload

Audio samples

Received on 160 m with active loop and RTL SDR with up-converter.

E2X on 160 m during ARRL 160 m Contest
7C1B on 160 m during the same contest

Comparison between signals received on 80 m (YB2BFF) with ICOM 7300 and 5 m whip antenna with loading coil, and RTL-SDR with up-converter, active loop antenna and GQRX software receiver.

ICOM 7300 with 5 m whip antenna on 80 m
RTL-SDR with active loop antenna on 80 m

PSK Reporter

PSK reporter link to see current stations received.

SARTS monthly meeting Feb 2021

Our February 2021 monthly meeting was held via Zoom. James, 9V1YC, emphasized again that SARTS has a drop in members and that we need member contributions helping to keep the club active and growing. If you are not a member yet and want to apply for SARTS membership, or you haven’t paid your annual dues, please do it online using our application/renewal web form.

Roland, 9V1RT, gave a short status report about our repeater. Klaus, 9V1KG, updated on the latest developments of the website.

Haoyan, 9V1HY presented about our SARTS QSL buro. As a member you can send and receive QSL cards free of charge via the buro.

Klaus presented about his experiences with software defined radios (SDR) and active antennas on Shortwave (HF).

You will find a copy of the presentations under the category SARTS Talks.

SARTS Meeting Jan 2021

The January 2021 meeting was held virtually via Zoom. It was also the 2021 Annual General Meeting (AGM).

SARTS Council 2021

The following members were confirmed serving as SARTS officers for 2021

  • President: James Brooks 9V1YC
  • Vice President: Benjamin Koe 9V1KB
  • Hon. Secretary: Jeff Yeo Nai Kwang 9V1AS
  • Asst Secretary: Aaron Wong 9V1AW
  • Hon. Treasurer: Harish Pillay 9V1HP
  • Council Member: Roland Turner 9V1RT
  • Council Member: Chu Haoyuan 9V1HY
  • Council Member: Arnold Cabahug 9V1CD

Office Bearer 2021

  • Examination (RAE): Ben, 9V1KB
  • Outward QSL Manager:   Kurita 9V1XX
  • Inward QSL Manager:  Chu Haoyuan, 9V1HY
  • Awards Manager:   Ben, 9V1KB
  • IARU Liaison Officer:   Jeff, 9V1AS
  • Webmaster:   Klaus Goepel, 9V1KG

The next monthly meeting will take place on Feb 25th, 2021 via Zoom.

AGM to be held on 28 Jan 2021

We will have our SARTS Annual General Meeting (AGM) on Jan, 28th, 2021. Due to the pandemic the meeting will be held virtually via Zoom. Members already received the meeting id and passcode via email.

Nominations

The following have been nominated by the council to serve for the 2021 work year:

  • President : James Brooks 9V1YC
  • Vice President: Benjamin Koe 9V1KB
  • Hon. Secretary: Jeff Yeo Nai Kwang 9V1AS
  • Asst Secretary : Aaron Wong 9V1AW
  • Hon. Treasurer: Harish Pillay 9V1HP
  • Council Member: Roland Turner 9V1RT
  • Council Member: Chu Haoyuan 9V1HY
  • Council Member: Arnold Cabahug 9V1CD

Agenda

  • Confirmation of the Minutes of the 50th AGM held on 24th Sep 2020 2.
  • Matters Arising from the Minutes of the 50th AGM 3.
  • To consider and accept the Council’s Annual Report for 2020
  • To consider and accept the Statement of Accounts for the year ended 31 Dec 2020
  • Election of Council Members and Office Bearers for 2021.
  • Welcome address by new council members
  • Election of Hon. Auditor for 2021
  • To consider the matter of monthly meetings by Zoom until such time when eyeball meetings may be resumed.
  • Any other business

HF Propagation: K-index, SFI, …

Some Rules of Thumb

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.

Links

Ionospheric Map

K-Index

VHF Repeater Issues – Reporting

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.

Thank You!