Last 10 QSOs logged

Last 10 qsos logged in clublog:

QSL Info on QRZ.com, HamQTH or 9V1KG contact me

My first QSO via Satellite

Finally I made it: my first ever qso in CW via satellite (RS-44). As I only have a free open view of less than 90 deg from my balcony, I have to wait for the right passes, and the time window is usually maximum 10 min.

sat-qso
Setup on the balcony

Using the IC-9700 with the 5 element log. per. antenna on my home brew az/el rotator, I was able to hear my own CW signal from the satellite and manage a qso with E21EJC in Thailand!

Software is Gpredict with Hamlib running on my Mac.

QSO on minute 6:37

Mini Satellite Antenna Rotator MK1

For my VHF/UHF station I am using a dual band five element log-per antenna, similar to the Elk log-per. It is actually an ideal antenna for portable use, as it can be assembled and disassembled easily and packed in a small size. Now the idea came up to use it for satellite communication with my FT-818. The only thing missing was a azimuth/elevation rotator to track the satellites.

I started with my own design, using a stepper motor for azimuth and a servo for elevation. After a while I cancelled the project, as I had too many problems with electromagnetic interference to the servo.

Searching for an alternative DIY solution, I came across the SARCNET website, and the mini satellite antenna rotator MK1.

I decided to build it, but to separate motors and electronics; purchased the parts and started the 3D print design. Below the details and the final result.

Overview of all 3D printed parts
  • tripod-mnt
    Tripod mount
  • top_mnt
    Top mount with hub for azimuth motor
  • m_unit
    Motor unit mounted to a 32 mm PVC pipe
  • el_unit1
    Housing for electronics, inside view
  • e_housing
    Housing attached to the pvc pipe
  • h-rail
    Cutout in the housing
  • p_mount
    Rail to attach the housing to the pipe
  • cw_1
    Counterweight using two ferrite torroids
  • counterweight
  • sensor
    Sensor housing
  • ant_holder
    Antenna holder
  • The whole package ready for portable use
  • LPDA_AZ_EL
    Test on my balcony

When I first time applied power to the motor drivers, the following happened with a loud bang! Luckily, it was outdoor on my balcony.

Exploded capacitor ...
The 100 uF capacitor was faulty, this is the result after applying 12 V to the board.

My thanks to SARCNET, the software works w/o problems. I only had another EMI problem, which could be solved finding a well screened micro USB cable and adding a few ferrites.

3D Printing for Ham Radio

Approximately a year ago I finally spent the money and bought a 3D printer. My main motivation was that I don’t have a workshop, and therefore I was not able to do even small mechanical things. I decided for the Creality Enders 3 Pro, as this printer has a large community, and it is easy to find tutorials and tons of other information on the web.

For the CAD program I ended up with Blender. It might sound like an overkill, but it’s open source and runs under Windows, Linux and Mac. Blender was the main hurdle, to get active with own designs, as it took quite a while to get familiar with the program using it for precision design.

From then onward, I have realized so many things using the 3D printer, and I can no longer imagine the hobby without this tool. Most items are printed with PETG.

  • Balun 1:9 housing
  • Balun 1:9 housing
  • Bias Tee
  • Bias Tee for active loop
  • Holder for VHF/UHF log per
  • Pulley
  • Drill press for my Dremel *)
  • Clamps for my active loop
  • Cap and holder for Micro Whip
  • Tube and rod cutter *)
  • Az/El rotator unit
  • Stand for FT-60 *)
  • My first design in Blender
  • Creality Enders 3 Pro

Links

Drill press: https://www.thingiverse.com/thing:1642711/files

Rod and pipe cutter: https://www.thingiverse.com/thing:3323294

FT-60 radio mount: https://www.thingiverse.com/thing:979456

SDR with Active Antennas for HF

A couple of weeks ago I started to gather my first experiences with software defined radios (SDR) and active antennas. I started with low investment, using the RTL SDR dongle, but I quickly realized that using the direct sampling mode for HF is not an ideal solution and added the Spyverter HF up-converter.

For my first trials I used a Mini Whip from RA0SMS as antenna, but the results were quite disappointing.

mini-whip

Finally, I ended up with an active loop antenna (see featured image), using the Cross-country Wireless Loop antenna pre-amplifier (10 kHz to 30 MHz version). The pre-amplifier is powered with 13.8 V via a bias-tee. Common mode chokes on the antenna line and all power lines helped to reduce noise, especially on the low bands. This is final hardware setup setup:

The setup is now running 24/7 on a Raspberry Pi 3B+ using GQRX and WSJT-X. I was surprised, how many stations and countries can be decoded down to 80 and 160 m.

PSK-80m

Further Information

Talk given during SARTS monthly meeting

PSK reporter link to stations currently received by 9V1KG

CQWW DX Contest SSB 2019

Last weekend I participated in the CQWW DX contest SSB part under the call sign 4E1A. Propagation was miserable on 40 m and 80 m; with my 100 W low power I was seldom heard by DX stations in EU or NA. On 20 m and 15 m propagation was acceptable, and I got even some openings on 10 m. Finally, I could exceed my points from 2018 and made 852 contacts with 62 DXCC entities and in 30 zones.

Contacts per band. Total 2287 QSO points and 191 Multipliers.

Raw score: 2287 QSOs x 191 multipliers = 436817 points.

NSPH 2020

Staying Connected

  • Date: June 13, 2020
  • Time: 11 am to 8 pm (Registration starts at 10 am.)
  • Location: Pacita Astrodome, Phase 1-C Sto. Rosario Drive San Pedro, 4023 Laguna (see Map below)
  • Fees: 700 PHP per participant

Due to the COVID-19 pandemic the scheduled meeting had to be cancelled. We will inform all registered participants about new plans and schedules on this website.

Online registration is open now! Please register here. Fees are 700 Pesos per participant and additional donations are always welcome. After your registration you will receive a confirmation email. Please transfer the amount due to the following account:

  • Account name: Normita D Torres or Violeta T Rivera or Emil L Virtudes
  • Account number: 1599-5781-33
  • Bank: BPI
  • Branch: BPI ATC Alabang

and email a copy of the bank slip with your name written on it to Mita (mita0955@yahoo.com ) , Zedith (solid_zedisu@yahoo.com) or Violeta (violetarivera736@yahoo.com).

You can upload your picture on the picture upload page. Pictures will be shown in the NSPH 2020 participants’ gallery.

Location Map

Looking forward …