AF - CQ Zone 33

ITU Zone 37











  KF5EYY SO2R & 6x2 Controller


This design of the SO2R is an improvement to KF5EYY SO2R v2 (See below). The audio switching part now includes 1:1 transformers mounted on the PCB. Two new PCBs were added to control a 6x2 Antenna Switching system via OTRSP (Wintest, DXLog or any logging software that supports this protocol).

PCBs 3D design on Proteus

The PCBs are designed to be stacked on an Arduino Mega controller.

A 6x2 LCD is used to show the band of each transceiver and the status of the headset (Left and Right ears).

PCBs mounted on the Arduino Board

The design is based on Relays control. The schematics are provided here. Please note that only relays for the control of Radio 1 Antennas are shown. Similar relays set up should be considered for Radio 2. Different relays (G5V-2 and G5Q-1A) were used in PCBs 1 and 2 due to unavailability of components in local market. Simple contact relays (G5Q-1A) can be used for both.

OTRSP is used to control audio in the headset and to 'read' each radio band to switch the 6x2 to the appropriate antenna. OTRSP Properties (in Wintest) have to be configured for each band (AUX11, AUX12, etc.). It is recommended to use a port monitoring software (ie. Device Monitoring Studio) to make sure the device received the right command from the logging software.



  260m Beverage Antenna


CQWW 160 CW 2017 was a good opportunity to set up and try the beverage antenna for receiving. The only station which fulfills space criterion is 3V8CB located in Borj Cedria camping center. The shack is 300m away from the beach (shouldn't impact beverage performance).

The antenna is 260m long set up at 2.2m high to allow for cars and people movement underneath it. The termination resistor is 450 Ohms with a 1m ground rod and 6 radials 5m each.

The transformer is a BN-61-202 with turns matching a 50 Ohms Coax.

Audio Samples of switching between the beverage and the Inv-L:






  CW Copying Efficiency Calculator


During a CW contest, we are sometimes called by so many stations at the same time. The number of stations we copy versus the total number of stations that called us (and we can hear them), depends on some factors like operator skills, focus, tiredness, etc.

I have developed an VBA Application that estimates operator's CW copying performance during any contest period he selects.

Macro window

The macro is embedded in an Excel Spreadsheet (link available below for download). When the file is opened, two worksheets will be found:

- "Log": user to import his Cabrillo log into that worksheet through data import from txt file. Cabrillo log is a delimited text file in which the TAB character typically separates each field of text. Select Space for delimitation.

- "Skimmed_Log": user to play the contest audio recording into CW Skimmer. Since CW Skimmer does not generate a skimmed stations log, Aggregator 4.0 (used for RBN) should connected to CW Skimmer. In order for CW to send callsigns of all the stations calling the user, “Do not send sports without CQ” in CW Skimmer has to be un-ticked. “Should Aggregator record Skimmer telnet traffic in AggregatorLog.txt?" to be selected in Aggregator's parameters. This file will be found in the same location of the exe file.

Once user plays the audio recording of the contest period he wants to examen, Aggregator should have generated a text file with the log of copied stations, frequency changes, etc. Simply import that file to the "Skimmed_Log" worksheet as done for the Cabrillo log.

Once done, user should press Ctrl+SHIFT+G. A window will appear. User to enter the Start/Stop QSO numbers that correspond to the contest period he played on CW Skimmer/Aggregator.

Skimmed Callsigns coloring

By pressing "Calculate", the macro will start by cleaning up the Aggregator log (keeping copied station lines only). After performing cross-check operations on the Contest Log and the Skimmed Log, the macro will display the following information:

- QSO distribution: by band

- Station in Skimmed: Number of skimmed stations by CW Skimmer. (It's not mandatory that CW Skimmer will copy all stations logged by the operator)

- Stations in Log: Number of Stations in Carbrillo log

- Worked Skimmed Stations: Number of stations that were copied by both the operator and CW Skimmer.

- Percentage of Skimmed Stations: Percentage of stations copied by both the operator and CW Skimmer, versus the number of station copied by CW Skimmer only. This is an indication of CW copying efficiency during the selected contest period.

- Returned Stations on the Band: The number of stations that operator didn't copy during the selected contest period but came back later and worked him on that same band. This represents the "recovered loss".

- Focus Period From/To: corresponds to the Start/End QSOs date and time.

Along with the information displayed in the window, the macro colors the callsigns in the "Skimmed_Log" Worksheet as follow:

- Red: The station was copied by CW Skimmer while the operator failed to copy it (Station heard but not worked).

- Green: The station by copied by both operator and CW Skimmer

- Yellow: The station wasn't copied by the operator in the selected period but came back later and was worked on that same band.

The macro gives the operator an idea on his CW copying performance and the "loss to be gained" if his performance is higher.

Download the Spreasheet here.

Sample logs are already in the file. The Skimmed_Log is for QSOs ranging from 800 to 950.



  Phased Verticals for 40m Band


In 3V8SS Station, all antennas have to be squeezed on the roof area. The station is equipped with a 7 Element CT-37HF Yagi for high bands installed at 7m high from the roof. Not far from it (around 8m away) a 5 bands Spider beam is installed at lower height. For low bands, the station is equipped with an inverted-V for 80 and a Ground Plane wire vertical for 40m.

With the sun entering low sunspot cycle, I was thinking how to improve my QSO count on low bands and more specifically on 40m. Being close to Europe is a big advantage.

Back in 2009, the 3V3S team from Germany have installed an 18m vertical for 80/160 using Spiderbeam poles. This fiberglass vertical was broken two times.

Fortunately, a 12m length of it is kept unharmed. I decided then to use it as a second element to the original 40m band - 12m length vertical antenna. I started reading in antenna books and websites about the best configuration. I then decided to make phased verticals using Christman method.

I shared the ideas with Ahmed 3V8CB and Ali 3V/F4HJD, both active members of ARAT. They were more than happy to come and give it a try.

Our objective was to have some gain towards Europe (at 0 deg Az) and NA/AS (respectively at 350 and 20 deg Az). Africa is behind us so there was no need to consider a direction switching relay.

Phased Verticals Schematics

We decided to move a little bit the original vertical and get some distance from the Yagi tower and Spiderbeam. Then we started making use of the old 80/160 poles as a second vertical. Both wire verticals were having two radials. Once up, we started cutting wire length till an SWR of 1.5:1 is obtained. Both verticals are electrically similar. We were a bit concerned about the electrical impact of the 5m mast holding up the new vertical.

I used VA7ST Christman Phasing calculator to calculate feedline lengths for an operating frequency of 7.050 MHz. A velocity factor of 0.66 was used for RG58 (50 Ohms). Both antennas were fed by 84-degree feedlines (about 6.5m) with additional 72-degree (about 5.5m) to the northern vertical (the front element). We didn’t have an antenna analyser to further adjust lengths, all had to be fixed by experimentation.

Phased Verticals installed at 3V8SS

Phased Verticals installed at 3V8SS

The triple point (where both feedlines are connected to the main coax) was mechanically attached. Myself, Ali and Ahmed made RX and TX experiments by lining up one element then two elements and check the performance. We checked as well the F/B Ratio by manually switching the feedlines between the two verticals.

The SWR of the system was very acceptable (1.5:1 on almost the entire 40 band). Here below are audio recordings of how RX and TX were improved by the new system:

TX Audio recording: my signal as recorded by ARDAM WebSDR located in Andorra which uses a half wave dipole for 40m: 2016-05-08 10:14Z 7030.0kHz

The first 55 seconds is using the phased vertical. At 2:40, I used a single vertical (old configuration). The difference is clear!

RX Audio Recording: IK5OJB on 40m:

0 to 34s: use of phased verticals beaming EU

35s to 58s: use of single vertical

59s to end: use if phased vertical beaming south



  KF5EYY SO2R Controller


Given the unavailability of ham radio equipment in Tunisia, I have decided to build my own SO2R Controller that should help me in the upcoming 2016 contest season.

I made a deep search on the net and found several designs; some are transistor based with front panel control switches and some are micro-controller based.

Arduino Uno mounted on KF5EYY SO2R board

I was very interested in K1XM Arduino based design. I bought an Arduino Uno device and started familiarizing with it. I was impressed with the ideas we can realize with it.

K1XM design (and code) appeared complex to me and uses features that I don't need, I inspired from it to make my own design and programming of the micro-controller ship. I have used "Serial Port Monitor" software to better understand how Wintest uses OTRSP (Open Two Radio Switching Protocol) to communicate with the device and update the program accordingly.

KF5EYY SO2R Controller

Few testing of Relays command on a breadboard were conclusive, so I purchased components and built the design on a perforated board.

The device is USB powered and enables audio control in the headphones (Radio 1 only, Radio 2 only, Radio 1 Left/Radio 2 Right, Radio 1 + Radio 2 on both ears with possibility to adjust audio level of Radio 2 for band opening monitoring).

The device enables also switching TX between the two radios. Dual CQ and other customized operating scenarios are possible through Wintest.

Relays and Status LEDs

Video of device testing in 3V8SS club station can be seen here:

KF5EYY SO2R 1.0 Schematics

I have then decided to replace the LEDs by an LCD and get the components implemented on a Printed Circuit Board.

I started testing the LCD on a breadboard. Be careful to the contrast adjust (pin 3) which should have a resistor connected to the ground. Direct connection is the silly mistake I made costing me 4 hours of investigating why the LCD does not show any message!

Further improvements have been brought to the schematics (thanks I4UFH). These include adding optocouplers to the CW connections to the radios. I also added capacitors for RF grounding on the audio outlet.

I made the PCB design using Proteus ARES 8. A lot of manual work was done to put the LCD on one side and the connection wires on the other side.

KF5EYY SO2R 2.0 Schematics


The Arduino code was improved to inform user Wintest is properly connected to the device. This is shown by a flashing [WT].

KF5EYY SO2R Display



  3V8SS Terrain Analysis


I made these terrain analysis to better understand the impact of location and terrain on 3V8SS station performance.

The terrain profile files were manually and roughly populated. The only available angle elevation statistics are for 7X. These were used since there should be no big difference.

The results shown perfectly match my seven years experience operating this station. The problem still with JA and NA paths on 14MHz; a good percentage of take-off angles are not workable.

EUROPE PATH (See topography)

EU - 14MHz

EU - 21MHz

EU - 28MHz

JAPAN PATH (See topography)

JA - 14MHz

JA - 21MHz

JA - 28MHz

USA PATH (See topography)

US - 14MHz

US - 21MHz

US - 28MHz



  3V8BB Terrain Analysis


At first glance it is clear that 3V8BB QTH is excellent and these mountains only affect SA path. However, I wanted to do the exercise, come up with charts that support this, and why not, look for improvements.

Thanks to N6BV and VA7ST for their support during the elaboration of this work and to S56A, W1UE and K6TU for their comments and ideas

You can download the study here.


Name: Ashraf CHAABANE "Ash"

Date of birth: 19/12/1983

Nationality: Tunisian

Origin: Kerkennah Isl. AF-073

Job: Process Engineer



E-Mail: ash.kf5eyy@gmail.com



3V8SS Radio Club


Call: 3V8SS
Location: Sousse City, Tunisia
Address: Maison de Scout Avenue Abou Jihed 4011 Hammam Sousse
Locator: JM55hu
LONG: 10.5941 E
35.85662 N Google map



 - CT-37HF for 20/15/10m

 - Spiderbeam for 20m~10m
 - Vertical 40m GP
 - Vertical 80m/160m GP
QSL Manager: LX1NO

LotW: OK




3V8BB Radio Club


Call: 3V8BB
Location: Bir El Bay, Tunisia
Address: ISAJC POBox 2055

Bir El Bay, Tunis, Tunisia
Locator: JM65er



Antennas: View

 -160: Inverted-V

 - 80: Vertical

 - 40: 3 Elements @ 20m

 - 20: 4 Elements @ 20m

 - 15: 4 Elements @ 20m

 - 10: 4 Elements @ 20m

 - PRO-67

QSL Manager: LX1NO/Direct

Direct Received QSLs: here

LotW: OK



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  2008 - 2016 © Ashraf CHAABANE - KF5EYY - TUNISIA