Ve6fi Amateur Radio

 

 

Remote Station set up

 

General Description of Remote Station

The idea of the remote station is to be able to operate the station VE6FI from home in Edmonton about 20 km away. This would allow using the antennas, radio and amplifier at the Ve6FI site without being at the site itself. One of the requirements was to have a reliable system that had some fail safe devices in case something did go wrong.

This version of the remote (December 2005) incorporate the use of a FT1000MP transceiver, all the antennas at VE6FI and the solid state auto tune Harris 1 KW solid state amplifier at VE6FI. It  incorporate a TCPIP internet  link as well as a two way simplex UHF link for the two way audio. The software used at the remote site would be TRX manager.

TRX manager runs on a P4 computer at the remote and the computer is connected to the 1000MP by a standard serial port. TRX manager communicates with the 1000MP and allows one to change frequency, change band, change filters and various other controls. It does not allow one to adjust the audio level out of the 1000MP. The output RF signal of the 1000MP goes to a Top Band decoder box that will switch to different antennas as the 1000MP changes bands. The 1000MP interfaces to the Top Ten decoder box by propriety 4 level code. For example when you switch to 40 meters, the Top Band decoder will switch the input to the 40 meter antenna.

At the home station (Edmonton) I run a P4 machine that runs TightVNC. TightVNC  is much the same as Netmeet and allows one to see the remote screen at the home station.  From the home station you connect via TightVNC and the LAN  to the remote computer which answers instantly and provides at the home station, the complete screen identical to the screen  at the remote. Thus you have control from the home station to tune, change bands and change all the controls as if you were sitting beside the computer at the remote. To key the transmitter you press the key button on the screen and the 1000MP will key. Previously we had used a dial up modem but we have found that the connection via the TCPIP protocol is much quicker. (see the wifi link)

December 2014 update - We are using TeamViewer to access the data. Instead of the UHF link for analog audio we are using audio via VOIP on the internet. Presently are using Skype but will be moving over to Remaud when we establish the permanent 2.4 GHz link.  Presently we are tied into a neighbors wifi but that is not working out because of capacity problems of their ISP

 

 

The audio from the remote to home as well as the audio from home to the remote goes over an UHF link. This link is comprised of two pairs of Mitrek UHF radios. These radios have a remote head and produce about 30 watts output in the 430 to 440 MHz band. The antennas used are 12 element horizontally polarized yagis with one mounted at 65 ft at the remote end and at 30 ft at the home station. This gives grazing conditions on the path and the signal is an S7 to S9. On HF receive, the signal from the 1000MP is taken at the 600 ohm 200mv output level and fed to the input of the UHF amplifier at the remote end. The UHF transmitter at the remote end is keyed and the audio is then received at the home station UHF receiver. In the transmit mode the uhf transmitter at home is keyed and the audio is received at the UHF receiver at the remote site. The audio is then adjusted for level and fed into the microphone circuit of the 1000MP. Now audio is going on the air over the HF rig. This describes the audio path. In fact we are looking at replacing the UHF radios with Voice Over IP on the TCPIP transport system.

In August of 2006 I added access to the remote site from a laptop computer which runs TeamSpeak Client  as well as TightVNC.  The last link from my home to the ve6fi remote site still runs on UHF radio. I installed the Team Speak Server/Client on my computer and a VOX interface that allows the voice that is coming off of the internet to key the UHF radio that feeds the remote HF transmitter.  On the path from the VE6fi remote to the TeamSpeak the audio from the HF radio output is sufficient to keep the squelch operated on the TeamSpeak Client interface. There is enough residual receiver noise on a dead band to keep the squelch operated. 

Now there are other circuits to develop to allow the following:

  • Additional antenna selection (LPT board)
  • Linear amplifier interface
  • UHF 30 minute timeout timer and identifier 10 minute timer
  • Audio level interface board
  • MFJ Timer for identifying on the UHF link
  • Relay box to wire in the additional antennas
  • Power supply to supply the various voltages at the remote
  • Correct keying sequence
  • Visual Basic software that allows selection of additional controls
  • Cable interface box to the linear amplifier
  • Home stations setup

 

Below is a screen shot of what I have at home or via the internet on my laptop when I am operating the station at ve6fi. Note that there is control of the radio via TRX Manager, There is the bottom panel which monitors the instantaneous power output of the transmitter. The remote pick up and software is provided by WaveNode. 

On the right side of the screen is the Visual Basic graphics which controls selection of 1 of 5 antennas on the band one is operating. It allows the Amplifier to be turned ON, Switching power to the towers, controlling two rotators which have larger monobanders on them.

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