Tag Archives: orbitron

Ham Radio

Orbitron & PST Rotator Interface with Easy Rotor Control

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This blog is an update of this – Pan & Tilt Orbitron Interface post as I’ve added some pictures of the kit used and I have finally got round to putting the Rotorcards in a decent enclosure.

The main controller is a ERC-M USB kit which interfaces with the PC and programs which are running , the Rotorcard relays  are controlled by the ERC-M, the Rotorcard also provides a positional feedback to the ERC-M.

Front panel of the Desktop housing for the ERC-M, the front panel has manual buttons for up/down tilt & left/right pan, LED's also show when internal relays are operated.

Front panel of the Desktop housing for the ERC-M, the front panel has manual buttons for up/down tilt & left/right pan, LED’s also show when a signal is sent to the Rotorcard relays.

The two yellow LEDs on the left hand side indicate the signal to the auxiliary relay.

The LCD display is showing the position in degrees, the number after Az or El is the feedback from the Pan & Tilt head, the numbers on the other side of the > are the output from the software, the ERC-M compares the two values and energises the appropriate relays which in turn operate the motors in order to keep the values aligned.2016-04-01 12.04.05 (Medium)

The ERC-M kit is the top left PCB, the desktop housing is also a kit comprising of the LCD display and front panel buttons.

2016-04-01 12.04.33 (Medium)

The PCB mounted inside the desktop housing is the 13.8v to 10v voltage regulator which provides a stabilized supply to the Pan & Tilt heads positional potentiometers.

An external 13.8v supply is required in order to drive the high current motors of the Pan & Tilt head.

2016-04-01 11.37.03 (Medium)

The two Rotorcards (one for Pan the other Tilt, or more correctly Azimuth and Elevation respectively) are enclosed, 13.8v can be fed to the relays here or at the desktop housing.

2016-04-01 12.01.25 (Medium)The three outputs from the ERC-M enter on the right hand side to the Rotorcards, the middle connector is the 13.8v – 0v – 10v supply.

The top Rotorcard relays operate for clockwise or anticlockwise supply to the Azimuth motor, the third relay is not used (auxiliary relay) as the Pan & Tilt head does not have an electro-mechanical brake fitted, if it did, relay three would operate in advance of the motor supply relays.

The bottom Rotorcard is for elevation, Up & Down.

On my version, the ERC-M is connected to a PC via a USB connection to Com Port 6, the position of the heads has already been calibrated using the provided software from Easy Rotor Control.

To start tracking satellites, the first step is to open Orbitron.

2016-04-01 11.56.40 (Medium)

This is a free download program, each time it is ran, check that the TLE files have been updated then select the satellite of interest from the right hand list, once this is done, click on the satellites on screen icon.

On the bottom tabs, select rotator and click DDE a small box should now open on the screen with live positional data of the selected satellite showing,  (a separate download is needed for the DDE function).

Open PST Rotator program:

2016-04-01 11.56.55 (Medium)

Using the PST Rotator settings configure the program to respond to Comm Port 6, use Orbitron as the controlling program, that the type of head ouput is GS-232 and Az/El is selected.

When the program is set to ‘Track’ as the above image, the displays show the actual position of the Pan & Tilt head by a black line with the green line showing where the head needs to move to, the green line is controlled via DDE from Orbitron.

A further setting I have enable is the link to weather information, this allows the mast to rotate into the wind when a trigger speed has been reached, this reduces wind loading on the mast and antenna.

2016-04-01 11.36.20 (Medium)This is a Dennard CCTV Pan & Tilt head and operates at 24v, 13.8v works it just fine with a maximum current draw of 600mA, I have commoned the potetiometers supply, so the minimum number or wire cores is 8:

2 – Pan Motor

2 – Tilt Motor

2 – 10v supply across positional potentiometers

1 – Signal feedback from Pan

1 – Signal feedback from Tilt

The next stage is to get some decent antennas for satellite reception.

Ham Radio

CCTV Pan & Tilt Head Interfaced to Orbitron and Ham Radio Deluxe

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I have blogged  previously  about using a CCTV head as a platform for ham radio antennas and have made a manual controller to do this.

I already have an Easy Rotor Control for my rotator but thought I would experiment with a dual control ERC-M unit in linking it to a Pan & Tilt head I was given.

I bought the ERC-M, two Rotorcards and enclosure with matrix positioning display and front controls for this project. The parts came as a kit and took a few hours to put together, a with a previous kit from ERC, the instructions were excellent and the unit operated first time on power up.

The Pan & Tilt head I have is 24vDC, but will work on 12vDC, once the connections were made to the Rotorcard relays, the next step was to calibrate to positional potentiometers which are part of the head and allow presets to be selected. (Note – the positional pots need a 5v to 15v supply across them, this can be taken from the Rotorcard but as no take off terminals are fitted this board, I fed the pots directly from the power supply)

The kit comes with a CD containing all drivers, manuals and instructions plus a calibration program and operating program, I opted for a USB version of the ERC-M, I needed to point to the USB driver location on the CD during the installation of the ERC-M, after installation, checking in device manager confirmed the controller was using Com Port 6.

Setting the calibration program to the correct com port number allowed me to first calibrate the Pan or Azimuth, once this was done after following the on screen instruction I calibrate the Tilt or Elevation, this needs a bearing to be entered when the platform is at the top position or 90 degrees to ground, once this is done, calibration is as the Azimuth by following the on screen instructions.

The calibration software can be closed and the operational software opened to test functionality of the head, clicking on the compass rose will take the head to that position.

I use Ham Radio Deluxe but the garage PC where I do my building has no radio related software, so I downloaded Orbitron satellite tracking software.

As the Orbitron does not have a physical connection to the ERC-M, the program Pstrotator was also downloaded as the interface as this will connect to Com Port 6 and drive the controller, the internal data exchange between Orbitron and Pstrotator is via DDE, this additional file needs to be downloaded from the Orbitron site.

Pstrotator was only used to test concept and I used the demo version which is time limited.

pst

I entered positional settings in Orbitron and clicked on DDE connect (a pop up will say if you need to download this if you haven’t already), if all I well, the positional data details of the satellite you selected will show in a small splash screen.

Opening Pstrotator, enter setting for the Com Port, type of head (Az & EL) and controller (ERC-D), close and then reopen the program, click on ‘track’ and the head will follow the trajectory of the satellite when in range.

A really cool feature of Pstrotator is the ability to take a feed from  a local WeatherUnderground feeding weather station (Chatteris Weather), when high winds are detected, the antenna will automatically turn to the wind reducing mast windage loading.

This use of a CCTV head to position tracking antennas is certainly a lot cheaper than buying a bespoke unit,  CCTV heads are made for external use and have decent torque, jut check if you get one that they are 24vDC and have the pots for presets, these come up all the time on Ebay for about £50, so all in you can have a quality tracking system for about £200.

I will mount the Rotorcards in a small enclosure and move everything next to the rig and interface with Ham Radio Deluxe, I have tested the tracking element with my existing Azimuth rotator, so I don’t envisage any issues with the ERC-M, the next job is to save up for some 8 core cable from the Rotorcards to the head!