Category Archives: Radio Ham

Ham Radio Mast Automation – Sensor Type

I have recently bought a winch up mast to gain greater height for my antennas, the electric winch lifts and lowers the inner section.

The 12v winch is designed for All Terrain Vehicles (ATV) and came from Winch-It complete with wireless remote control, in order to use the remote controls out of direct sight of the mast, I fitted proximity switches which detect when the mast is either fully raised or lowered, and then stop the winch.

The short YouTube video shows the type of switch used and its detection distance.

A more detailed mast installation and control blog will follow.

Note – As demonstrated in the video, the orientation of the magnet is critical for correct operation, also the output from the switch is a signal voltage and a relay module must be used to avoid damaging the switch.

relay interface
Relay Interface Ebay £6.29

Shack Clock Modification

The clock in my shack is one of those which receives a radio signal enabling it to be constantly accurate and it will automatically adjust for British Summer Time, as the contact time in paper and electronic logs is recorded in UTC (Coordinated Universal Time), I decided to get an additional  conventional analogue wall clock and customize it a little.

SAM_5394 (Medium)

The battery powered clock used was described as a kitchen wall clock, item code 257946  costing £3.99 from B&M’s.

I wanted the clock to show 24 hour format, that it was in UTC and my call sign, I decided to print the detail onto 80gsm paper, printing a circular cutting line and stick the addition to the clock face.

I used Visio for the drawing and the template can be downloaded here, a jpg version for editing in paint is here.

The clock came apart by the removal of a few screws, the hands were then removed, the clock mechanism was held in place with a nut, once removed the disassembly was complete.

The printout was cut, and adhered to the clock face with a ‘Prit stick’ type glue and the clock reassembled, job done!

If I had a working colour printer I would have highlighted some of the new detail and maybe even added a picture, but the cost of printer ink is didn’t warrant the expenditure on this little project.

The clock face on the clock I used was slightly over A4 size, if it was less than A4, I would have printed a completely customized new face so no difference in contrast would be seen.

First Australian Receive of M0HTA

I have posted previously about a distant contact logged using the program WSPR using 10 watts, for this Australian contact my transceiver was using the 30m band, mode USB with an output from the rig set to 5 watts.

prog

After the PC clock has been synchronized to the network, I run the software which is linked to my transceiver via serial COM port 1, selecting the chosen band, the software adjusts the transceiver to the correct frequency and will then receive and decode signals, before waiting a pre determined time, before transmitting my station call sign, QRA locator and power output.

Whilst my station is transmitting, other stations who are running WSPR are in listening mode and I’m listening for their signal when I’m not transmitting, this allows a map of interconnections of, I can hear them, they can hear me or both.

oz

I couldn’t believe that within an hour of running the program my signal was received in Australia, up until that point it was mostly Europe which was to be expected, I left the program running for12 hours in total, and the map shows where I had contacted in that time.

Completed Crowbar Circuit Build

Link to Crowbar Circuit Part 1 which has the circuit diagram and part list.

The last part of the project was to mount the circuit in the enclosure, I also bought a panel mounted digital voltmeter which is really useful.

Unit sat on top of the TS-2000 displaying the voltage.
Unit sat on top of the TS-2000 displaying the voltage.

Internal views of the unit, I have modified the board from that shown in Part 1 by the addition of a fuse holder mounted on the veroboard, this has a 2A slow blow fitted and protects the non terminal post outlets.

SAM_5389 (Medium)

SAM_5388 (Medium)

SAM_5386 (Medium)

SAM_5385 (Medium)

SAM_5384 (Medium)

SAM_5383 (Medium)

 

 

 

Kenwood TS-2000 Footswitch PTT via SignaLink Interface

Latest Version – Modified 14 June.

I’m slowly building up my station and thought that a foot operated ‘Push to Talk’ (PTT) would be a good addition, the switch I bought was an Eagle Electronics G028B Momentary foot switch with 6.35mm plug, this is a type used by musicians so is very robust and was bought from Juno Records for £8.41 inclusive of postage, delivery was within 2 days.

SAM_5374 (Medium)

The G028B came with a 6.35mm mono jack plug, this was removed and replaced with a 2.5mm jack as the socket which is used later has a smaller footprint than a large jack socket.

The rig has two connections where it is possible to operate the PTT, the first is the microphone socket on the front of the rig, the other is using a connection available from ACC2 at the rear of the rig.

I was looking at a way of breaking into one of these cables in order to make the connection to the footswitch when I thought of using the SignaLink box as a breakout.

signalink (Medium)

The SignaLink is connected to the ACC2 socket on the rig using a cable marked SLCAB13K, the connection into SignaLink is an 8 wire RJ45 plug.

The connections are (Refer to page 95 of the Kenwood  instruction manual for ACC2 pin functions):

  1. RJ45 SignaLink    3-Kenwood ACC2
  2. RJ45 SignaLink    11 -Kenwood ACC2
  3. RJ45 SignaLink    9-Kenwood ACC2
  4. RJ45 SignaLink    13-Kenwood ACC2
  5. Not connected
  6. RJ45 SignaLink    4-Kenwood ACC2
  7. RJ45 SignaLink    8-Kenwood ACC2
  8. RJ45 SignaLink    12-Kenwood ACC2

The existing SignaLink configuration links for my rig was:

  1. SPK
  2. MIC
  3. PTT
  4. —  Use this to connect to Footswitch and 8.G to operate PTT
  5. G
  6. G
  7. G

The unconnected pin 4 from the RJ45 is connected to pin 13 on the rig, this allows the PTT to operate and NOT disconnect the Mic.

SAM_5367 (Medium)SAM_5368 (Medium)

I left enough lead on the footswitch socket so it will thread through the SignaLink enclose without taking the socket apart.

Removing  jumper 8 out of the holder, strip a small section of insulation and solder the flying leads to the outer of the 2.5mm footswitch socket, returning the jumper to the same position as it was removed from, for the  inner connection of the 2.5mm socket a wire was inserted into he empty number 4 socket on the side nearest the RJ45 socket.

SAM_5379 (Medium)

SAM_5372 (Medium)

This turned out to be a quick, cheap and neat workaround rather than hack into cables or adding additional plugs and sockets to make a breakout.

All done and working in under an hour,  the footswitch is ‘press to make’ it does not need to be left plugged in, so can be put out of the way until needed.

Hope this was useful.

Crowbar Overvoltage Circuit to Protect Transceiver

I was looking for a simple circuit to protect my radio  and auxiliary equipment  from overvoltage and found a circuit diagram and full description on Phil Salas – AD5X site.

The voltage protector file including circuit diagram and full parts list is available for downloadable here – Vprotect.

The circuit is designed to ‘blow’ the supply fuse to the equipment in order to protect it, the protection is from reverse polarity as well as  transient spikes and damaging overvoltage.

The specification for the Kenwood TS-2000 is 13.8v +/- 15% ( Total Maximum voltage 15.87v), this circuit will only allow 14.8v to pass before the protection crowbar circuit operates.

The components are sizes for 40A, the Kenwood maximum current draw is 20.5A, so well within capacity.

SAM_5357 (Medium)

SAM_5358 (Medium)

The circuit board could have been made marginally smaller, but I was too lazy to trim it down!

SAM_5360 (Medium)

This shows the test setup with the power supply units (PSU) current trip set low in order to monitor the tripping voltage, on the left of the PSU in between the knobs marked CURRENT, their is a small LED with C.C. for Constant Current, the circuit is working passing 13.73v to the meter.

SAM_5362 (Medium)

The voltage from the PSU has now been increase past the crowbar limit of 14.8v and the C.C LED is ON showing that if this was a fuse it would have operated to protect the transceiver, 14.8v is the maximum voltage that will ever reach the transceiver, no matter what!

Parts: – These were from UK ebay

1.5KE 15 TVS Diode 1.5KW 15v DO-21 – £1.69

Thyristar 40A, 600v TO-220 TYN640RG – £3.19

IN5245B Diode Zener 15v 0.5w – £1.42

Radial Electrolytic Capacitor 1uF 50v – £0.99

Resistors 27k, 10 Ohm and Veroboard I had already

Less than £8 to protect an expensive radio, filtered speaker etc. I will post up pictures when I have this mounted in an enclosure.

G-1000DXC Rotator Interface

Ordered a Yaesu G-1000DXC from Sands Marine, the service received was second to none and I would recommend them, unfortunately the rotator doesn’t come with the necessary connections, these were bought from Waters & Stanton.

Rotor cable will be bought from Westlake Electronics when I know the required length.

I want to interface the rotator with Ham Radio Deluxe, the Yaesu interface box is simply stupid money at £510!!, I bought a kit from Easy Rotor Control for  total cost of £64 including 6 pin DIN plug which will perform exactly the same function (Interface on its own is £57).

The kit was built in a couple of hours and worked immediately, the documentation comes on a CD and is brilliant.

SAM_5336 (Medium)

 

SAM_5344 (Medium)

I had an enclosure lying about which was an ideal fit fro the pcb, the front panel has a USB connection for the PC, a DC input which will take 13.8v so it can be fed directly from the PSU feeding the transceiver and the lead which goes to the rotators controller.

The CD which comes with the kit has a test and calibration software program which allows functional testing and saving of settings.

The interface is all working and I’ve posted a YouTube Video of it controlling a rotator via commands sent from Ham Radio Deluxe.

Mag Loop – Part 4 – Initial Values

Did a rough make up of the Mag Loops coupling loop, used RG213 to start with, then tried 7mm copper pipe, both reading were very similar, I still have some tweaking with some other options yet before I decide on which to use on the completed set up.

The VSWR reading have been very encouraging, with the capacitor closed (meshed) it tunes from 2.884MHz to 21.292MHz with the capacitor fully open (unmeshed).

mag loop v1 22 March 15

The sample points were taken at the bands PSK frequency (apart from the first and last) and shows that it will tune from 15m to 80m.

Mag Loop Part 3 – Capacitor motor drive

Thought I’d give an update on the mag loop project, I’ve been busy making the capacitor support, as it is important to reduce resistive losses, I mounted the capacitor using 1.7mm thick sheet copper, the main mounting is one side of the capacitor and I have brought the connection off using 28mm copper pipe, this goes to a compression fitting in which I have also soldered the olive the reduce where possible electrical resistance.

The reason for using 28mm pipe is that I can use pipe reducers when I come to play with different pipe thicknesses and configurations.

The top of the capacitor is the second terminal, I bought a small piece of 54mm copper pipe, after putting a small slot in the side, this slides neatly over the end of the capacitor and is secured in place with a jubilee clip, a 28mm copper stub pipe was soldered onto the 54mm piece completing the loop terminations.

The capacitor assembly is mounted on a cut down plastic bread board, the shaft from the capacitor has a flexible 12mm to 6mm coupling reducer, the linkage to the stepper motor is with 6mm diameter nylon threaded rod, this allows for conversion of rotary movement to linear movement is I decide on using limit switches or positional potentiometers at a later date.

The stepper motor is a Bipolar NEMA 17 200 step, 12v @ 350Ma, the 5mm motor shaft has a flexible coupling affixed, this not only compensates for any out-off alignment but also allows the 6mm threaded rod to connect to the 5mm shaft. Nylon was chosen for the motor linkage as this insulates is from the high voltages which develop across the capacitor when in use and the motor, the capacitor is rated ay 4Kv and I will have to throttle back output power to ensure this is not exceeded.

I opted for a stepper motor over a DC motor after reading that the brush noise could be a problem, it is easy to convert from stepper to DC should I need to in the future, it is also easier and cheaper to control a DC motor, so I did consider this option before committing to the stepper motor.

I’m using an Arduino Uno clone (www.sintron-hk.com) with an 5v rotary encoder, the Arduino is connected to a A4988 Stepper Motor Driver Carrier with Voltage Regulators.

The A4988 can be supplied with an input voltage of up to 35v and it has on board 5v and 3.3v regulators, this reduces the need for external components or the need for a separate power supply for the motor and logic circuits, I use the A4988 5v output to power the Arduino when in use making for a neat solution.

20150315_184832[1]

This is the unit on the desk allowing me to play and tweak.

Link to YouTube video showing the control of motor.

Although not shown in the youtube video, the A4988 allows microstepping, rather than simply moving the motor in 1.8 degree steps which would be to course to control the capacitors movement accurately enough to optimize tuning, this feature will give excellent adjustable control.

The control unit which will be in Part 4, will have the rotary encoder for controlling motor rotation and direction and a multi position rotary switch, the switch positions will be ON >> Half Speed >> Quarter Speed >> Eighth Speed >> Sixteenth Speed.

The biggest obstacle in getting this working was my zero understanding of the programming language used for the Arduino, I spent considerable time looking for a suitable program I could download, these are referred to a Sketch’s, and finally I found it here and I can’t thank them enough for making it avaialable.

As the Arduino is open source, their are stacks of forums and areas for help, eventually I will play with the Arduino as it is yet another facet of the hobby.

Bill of Materials to motorize:

Ebay Vendors –
54mm copper pipe £2.40
6mm Threaded Nylon rod £1.52
Flexible shaft couplings £4.28
Rotary encoder £0.99
Sinton Arduino full kit £30.95 (replacement Arduino board as the kit one is in use £4.50)
Copper sheet £7.50

B&Q –
28mm Couplings £4.50 each

Hobby Tronics –
A4988 and heatsinks £7.78

Adafruit –
NEMA 17 stepper motor $14.00