A dish for Es’Hail-2, QO100

Last year I experimented with using a 13cm band yagi for the up-link and an LNB strapped alongside my horn on the dish I use for terrestrial work for the down-link.

I’ve now put a dish up for the Qataris’ Es’Hail-2 satellite. It is a 1.1m off-set PrimeSat dish.

Prior to putting it up,  I had bodged a bit of aluminium  box tube to take the dual-band feed. I checked the dish’s focus with a few stick-on mirrors and the sun as an light source. There did seem to be a bit of distortion in the dish, though it looked in excellent condition, with no visible damage. I may be able to squeeze out this distortion using the braces for the LNB arm.

Bearing in mind how windy it gets here I’ve used belt and braces in mounting the dish. I decided not to get the larger 1.3m dish. I felt the 1.1m dish would be easier to manoeuvre  up to the roof and also it would be less affected by wind. I’ve used two steel chimney lashings to hold two brackets. I decided the usual aluminium pole might not be up to the job, so I set a section of steel scaffold pole in the brackets. The dish’s two clamps are fixed to the bottom of the pole. In case of the dish clamps somehow working free, there is a third clamp at the bottom of the pole to stop the dish dropping off.

I’ve fitted braces to the LNB arm to hold the arm steady in the wind.

Being low down on the chimney and on the easterly side of the house, the dish is in the lee of the strong westerlies and south-westerlies.

IMG_20200429_124932

The 13cm patch antenna in the bigger plastic box is not really working as circularly polarised. It is more like linear, effectively from a dipole, but the return loss is quite good. The patch is fed with a shortish length of Ecoflex 10.

The LNB has a bit of “satellite” coax taking the signal back into the station. I found the connectors on my thin “WiFi” coax were very poorly fitted. I use this to carry the 27 MHz reference oscillator signal to the LNB. I soldered a proper SMA connector on the LNB end of the cable. An LNB lens takes the signal rom the dish which is then piped along a short length of copper waveguide (22mm domestic copper pipe) into the LNB. The waveguide is held by pipe clips mounted on short lengths of stainless steel studding. The LNB has a bit of a twist on it in an attempt to optimise the match to the polarisation from the satellite.

I sealed all the connections with self-amalgamating tape.

See Dual Band Feed construction.

Note: I had originally mounted the N-type socket for the patch feed with the socket mounting flange inside the plastic box, but this meant the N-plug did not mate reliably, so I re-mounted the socket on the outside of the box.

23-April-2020 opening on 3cm: Kjeld OZ1FF

I was chatting to Tony on 3cm. We were checking beacons on the continent on 3cm. He could hear DB0GHZ which I could not. I could hear beacons in the Netherlands which he could not: PI7ALK, PI7RTD and PE9GHZ. Neil G4DBN joined us.

A few of us worked Kjeld in JO45BO at 670 km. I chatted with him on SSB. He gave me 55 for my 3W to the 80cm dish.

23-Apr-20 1949 OZ1FF 57 55 JO45BO

Usually, when I can hear DB0GHZ then I can work Kjeld, but I couldn’t hear that beacon this time. I could hear no other beacons except those in the Netherlands. Tony is not that far from me, but his beacon view was completely different to mine.

21-April-2020 23cm UKAC

This was hard going. I heard too little of Jon GM4JTJ to make a contact. I missed Nick G4KUX, who was very strong. Richard GD8EXI could not read me; we hardly ever fail. I could copy Conrad PA5Y weakly, but he lost me. Gordon GI6ATZ read me on CW! So Gordon was my best DX.

Conditions seemed a little better to the south east.

 

Ublox NEO-6 GPS feeding an Arduino MEGA 2560 to display Latitude & Longitude on an LCD screen

The Ublox NEO-6 board cost about £5 with its antenna, including delivery. This feeds an Arduino MEGA 2560 with a 1602/HD44780 LCD Screen-Keypad Shield (for MEGA). I didn’t actually use the keypad buttons, but they are easy to program in. You might use one to flip between Lat/Long and Maidenhead Locator, for instance.

I fed about 4V, smoothed a bit, into the Vcc (+) and Gnd (-) on the NEO-6 card and 12V into the Arduino (when not powered via the USB cable from the PC).

The serial data came from the Tx pin on the NEO-6 and fed the pin 19 (Tx again!) on the Arduino board. (I did think Tx on the NEO-6 should feed Rx on the Arduino board, but that didn’t work). The NEO-6 drew about 70mA typically, but the current varied a lot.

The wiring diagram is simple. I used a 5V regulator on the project breadboard to power the NEO-6. The regulator got a bit hot, so I put a heatsink on it.

DSCF0364

200411_NEO-6+Arduino_MEGA

The ‘o’ in the top RH corner of the display indicates that the program has initialised and entered the main loop. The ‘s’ in the bottom RH corner indicates that the serial telemetry from the GPS card is being received (the white wire in the picture above). A flashing red LED on the NEO-6 card indicates satellites have been detected. When the lat/long display updates, then the NEO-6 has found a position.

I used float type variables lat and lon to hold the latitude and longitude floating point numbers. These seemed to hold 6 significant digits reliably. I used the dtostrf() function to format the numbers for display.

My lab/shack is well screened with sheets of insulation covered in aluminium foil, so GPS satellite signals are very weak. My Garmin Etrex GPS could see no satellites at all. The NEO-6 (with its separate little patch antenna plugged in) not only found satellites (a red LED on the board flashed), it also locked on to give a position. So the NEO-6 has a useful sensitivity. The little coax antenna socket has 3.3V on it, so I’m guessing the little patch antenna is active, not passive.

I compared the Etrex readings with the NEO-6 readings for the same position. They agreed up to the third decimal place (of degrees). I took the maximum and minimum readings over about an hour. Here are the differences between maximums and minimums:

    Etrex                    NEO-6

Lat:       0.00006                0.00014

Long:    0.00040                0.00025

So the Etrex varied less on latitude and the NEO-6 varied less on longitude, as different satellites dropped in and out.

I found that when I switched the IDE to Due that the program would not compile as the  dtostrf() function was missing. I’ll try to re-write the program in order to avoid dtostrf(). There seems to be some inconsistency between the libraries for the different types of Arduino.

Program below (supplied as is, no liability):

// GPS_NEO6_position_read-out_V3 (c) GJ Coyne G3YJR
#include <LiquidCrystal.h>
#include <TinyGPS.h>

float lat = 54.123456, lon = -2.123456; // declare variables for lat and long
static char lat_ch[13], lon_ch[13];

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);         // Set LCD interface pins

TinyGPS gps;                                            // declare gps object

void setup(){

Serial.begin(9600);              // connect Serial0 for PC comms

lcd.begin(16, 2);                    // initialise LCD screen
lcd.clear();                              // clear the LCD screen

Serial1.begin(9600);            // connect gps input on pin 19, Serial1

dtostrf(lat,10,5,lat_ch);       // lat_ch 10 chars, 5 after decimal point
dtostrf(lon,10,5,lon_ch);     // lon_ch 10 chars, 5 after decimal point

lcd.setCursor(0,0);               // col 0, row 0 (top row)
lcd.print(“LAT “);
lcd.setCursor(3,0);               // col 3, row 0 (top row)
lcd.print(lat_ch);

lcd.setCursor(0,1);               // col 0, row 1 (bottom row)
lcd.print(“LON “);
lcd.setCursor(3,1);               // col 3, row 1 (bottom row)
lcd.print(lon_ch);

}

void loop()
{

lcd.setCursor(15,0); lcd.print(“o”);   // ‘o’ in top rh corner for ‘On’
lcd.setCursor(15,1); lcd.print(” “);    // clear serial i/p received field
while(Serial1.available())     // check gps serial i/p data on pin 19, Serial1
{

// lower-case ‘s’ in top rh corner for Serial o/p received
lcd.setCursor(15,1); lcd.print(“s”);

if(gps.encode(Serial1.read()))     // fetch gps data

{

gps.f_get_position(&lat,&lon); // fetch latitude and longitude

dtostrf(lat,10,5,lat_ch);             // lat_ch 10 chars, 5 after decimal point
dtostrf(lon,10,5,lon_ch);          // lon_ch 10 chars, 5 after decimal point

lcd.setCursor(0,0);                    // col 0, row 0 (top row)
lcd.print(“LAT “);
lcd.setCursor(3,0);                    // col 3, row 0 (top row)
lcd.print(lat_ch);

lcd.setCursor(0,1);                   // col 0, row 1 (bottom row)
lcd.print(“LON “);
lcd.setCursor(3,1);                   // col 3, row 1 (bottom row)
lcd.print(lon_ch);

}
//fi

}
//endwhile

delay(1000);

}
//endvoidloop

Auna iTuner CD – internet radio/DAB/FM tuner; Sony HCD-EH45DAB HiFi repair/modification.

The Sony Hifi (HCD-EH45DAB) has a DAB tuner, FM tuner and a CD player. It lacks presets for radio channels, so it takes 11 clicks to change from Radio 4 to the BBC World Service on DAB.

200411_Sony_CMT-EH45DAB_front

Also the Sony Hifi had had a fault with the volume knob for some time: turning the volume up might raise the volume, but it might also take it down. The knob was not a pot, but some sort of digital rotary sensor, probably feeding a microcontroller.

Inside the Sony HiFi I found a loose electrolytic capacitor on the main board. This capacitor tested faulty on an ESR meter, so I replaced it (33uF, 50V). Surprisingly this seemed to fix the volume control problem. Or maybe I re-seated some internal connectors and that fixed the problem? I don’t know.

I modified the Sony HiFi system by adding a pair of RCA/phono ‘audio in’ sockets on the back so that I could feed in the Auna tuner. I wired these to a new/replacement stereo audio jack on the front panel. The replacement jack socket has pass-through input pins (active when no jack is plugged in). I wired the pass-through pins to the new input sockets. There are red and white phono plugs plugged into them in the picture below.

200411_Sony_DM45DAB_back

200411_Auna_iTuner_CD

Plus Points of the Auna:

  1.  It fitted nicely below the bread bin on the kitchen window sill.
  2. It has nice knobs for menu selection and volume control.
  3.  The DAB tuner is excellent and it is helpful to have the station information on the screen.
  4. It lets me listen to Sheffield Live!, Test Match Special, BBC Radio 4 Extra (ne BBC Radio 7), BBC World Service (such a blessing when the Archers is on Radio 4 and Dessert Island Disks with Sue Lawley is on Radio 4 Extra!) and Radio Jamaica (for jamming along when doing the washing up).
  5. Starting a Spotify app on a phone shows the Auna as a play option. Selecting this gives wireless play from the phone to the Auna.
  6. The audio distortion and noise levels are low.

Minus Points

1.  There is no pause for live radio. I want a pause in the same way that satellite TV can be paused.

2.  There is a clicky button labelled “Mode”. A more meaningless label is yet to be thought of. It turns out to be DAB/FM/Internet/Spotify selection. It is easy to miss your selection & you can’t go back, so you have to click your way through the list again. Please Auna, put a knob in for this, one that can turn both ways. Label it DAB/FM etc., because that is what it does.

3.  I opted for a black case. You need excellent eyesight and good lighting conditions to read the labels on the front panel. They are in a small font and grey on black is hard to read. The Auna comes with a small remote control. The labels on this are even harder to read than those on the front panel. A magnifying glass helps. Auna please consider your visually impaired users. There are lots of us!

4.  Setting it up in order to get the Internet Radio station lists is a bit fiddly. I was impressed that the list included Sheffield Live, a local community radio station.

5.  I want a set of pre-set buttons on the front panel which gives me instant selection of my favorite radio stations regardless of whether they are FM, DAB or internet stations.

6.  The audio out level seems rather low, so I’ve set the Sony’s volume level to its maximum.

7.  The menu system is clunky. Navigating down one level is fine. I don’t see how to go up one level using the controls on the front panel.

8.  I find internet radio stations drop out from time to time, but that is probably to do with the internet and the reliability of internet radio. The problem is that the Auna does not automatically re-connect. I have to go back to the pre-set & re-select it manually. I find I don’t listen to internet radio much as it is a frustrating experience; internet radio was the main reason I bought the tuner!

9.  When the list of pre-sets is selected, the selection highlight is always at the start of the list. It would be more helpful if it showed the last selected station.

(My apologies for the stray light in the photographs above).

Can’t send message with O2 – UK – error 42. Huawei/Android phone

This is a mystery message which O2 sends me on my new Huawei Honor 10 Lite android phone. What is error 42?  O2 chat help seems to be shut down at the moment.

The phone is already annoying me in various ways.

Google Play seems to wan’t to access all my contacts details. It nags me incessantly about “service errors”.

The overall message from Android to me seems to be “you will give us access to all your data; we will torture you until you give in”.

I may yet go back to the Blackberry. It couldn’t run apps, but life was more straightforward and peaceful.

5-April-2020 Low Bands contest

In spite of the nearby high pressure, conditions were very poor. On 23cm band I failed to work Gordon GI6ATZ and only just scraped a contact with Richard GD8EXI. I failed with Pete GM4BYF.

20040523

 

I worked some of the usual suspects on 13cm in the 2.32GHz sub-band.

20040513

 

And the usual suspect in the 2.30GHz NoV sub-band: Keith G4ODA. Unfortunately, I didn’t get the points for this contact as I entered his callsign as G40DA. Spot the difference. I didn’t!

20040512