A Go Box HF Portable

A Go Box HF Portable – A Solution To Increase Radio Enjoyment!

So you’re thinking about going HF Portable!
On the surface, while it’s a great idea to get out into the open spaces with low noise floor and fresh air, however when it comes to; “Now what do I need” part of the thought process, it starts to gets a little confusing for those contemplating portable operation for the first time!Case Open with Computer connected and station ready for use.

Perhaps there are some of you who may have participated in the “Lighthouse Weekends” as second operator or others may have operated in the “John Moyle Field Days” by visiting a station that had been setup by someone else. No matter what the occasion I am sure, for most people, this type of operation leads to a great time being had by all!
The only downside for these activities is when things just don’t quite work as expected.

This can easily occur when a significant piece of equipment is forgotten or something as simple as a piece of coax cable and or a connector is forgotten.
Alternatively it may be that the antenna system failed to provide the results expected.
While I acknowledge this is all part of the experience of going portable however these events can and do have a habit of testing ones patience to the limit.

Over the years I have operated in a multitude of locations and circumstances  in this country and overseas with a variety of weather conditions thrown in for good measure. Yes, I have had equipment failure, forgotten critical components and had the odd antenna and mast fail. As the old expression goes, what doesn’t kill you will only make you stronger!
I do wonder however, how much extra strength do I need to gain, before I have an HF portable experience that works successfully from beginning to end.

I decided to write this article to outline the steps I have taken to minimise the common traps and disaster areas that can destroy the pleasurable experience of going HF portable.

Preparation
Operating Frequencies
The Equipment
The Antennas
Setting up the station
The Power System
Computer Support

While I acknowledge these areas are not world shattering in their selection, it is the activity that surrounds each step that can make or break HF portable operation.

Preparing to go HF Portable
There are a number of things that are immediately obvious to most operators when HF portable is suggested:

Where will I go?  What equipment will I need? What antennas will I need? Lastly what power source will I use?

The later seemly becoming almost an afterthought.

Without a doubt these items are all important, however it has been my experience that what tends to get lost in the fervour of the moment are the vital ingredients.
It is the little things such as the operating position, the coax adaptors, patch leads, power connectors, the headphones, fuses and the like. Without these items, the day/days may turn out to be less than ideal.
To offset this and to help me gain greater enjoyment in my HF Portable operation, I have developed a HF portable station that is completely self-contained. In so doing the problem of missing items has been offset if not totally eliminated.
The station I have assembled requires only three (3) external connections: Antenna, Computer and Power.
This means that station can be transported to any new location quickly and efficiently with little advanced notice!

Operating Frequencies
Before beginning to assemble the station one further question needed to answered; what frequency range was I going to use for my portable operation?
Without answering this question, decisions relating to equipment, antennas, power sources etc., would have little relevance.
The decision in reality was simple and really focused on gaining maximum enjoyment from my endeavours.
Experience has shown there is a direct correlation between the number of contacts undertaken and the enjoyment derived. If the enjoyment factor was top of my list, then it was mandatory that the station must support 40 meters to 10 meters to take advantage of the maximum concentration of operators. I have, however, always been interested in VHF and UHF and since most modern transceivers are equipped to operate in the VHF range (6 meters is an example) and in some circumstances VHF / UHF frequency ranges (2m and 70cm) are included, then it would be remiss of me not to consider these frequencies as well.

HF Portable Block Diagram

The Equipment
With the frequency question resolved, the next area to be addressed was what equipment was I going to use for my portable station. While pondering  a solution I realised there still existed one outstanding question to be addressed before I could be sure that my selection of equipment would satisfy my requirement. The question focused on what power level was I going to use?
The answer to this question would have a profound effect on the size and type of power supply that would be required by the portable station.
After considerable deliberation I decided that I would stay at the 100 watt PEP level for my portable station because when considering all the issues and problems surrounding the power system required to raise the output power of the station, it was simply was not worth the effort!

MFJ-945E and the IC-7000

With these issues resolved the transceiver that I decided to use for my portable station was an ICOM IC-7000. While I am aware there are number of other possible solutions, this transceiver “ticked all the boxes” for me. Predominately it provides multi-mode frequency coverage up to and including 70cm with 100 watts available from 160 meters to 6 meters, 50 watts on 2 m and 35 watts on 70 cm.

As many operators would know, the IC-7000 transceiver mirrors many of the features found in the larger and more expensive units in the ICOM range and considering its small size makes it an ideal choice for a portable station.

An added feature of the IC-7000 is its ability to be computer controlled using the “ICOM CI-V Serial Bus” that provides a raft of control commands that allow the transceiver to be controlled from software such as “Ham Radio Deluxe”.
To achieve this flexibility, all that is required is a “Level Converter” to connect transceiver to any computer. Searching the internet, it soon became obvious that there were numerous solutions to satisfy this interface requirement. But which solution would I choose?
As I was considering using the Ham Radio Deluxe software program for logging and control of the transceiver it seemed logical to consult the programs manual to see if there was a solution on offer. A quick read of the documentation confirmed a plethora of interface circuits. The circuit I settled on was a copy of the ICOM CT17 based on the Max232 chip with a small number of support components. An ideal solution for my portable station. The solution was quickly built and enclosed in a die-cast box.

Computer Interface

Computer Interface

The ICOM IC-7000 while ideal for all the reasons outlined, lacks the ability to provide D-Star on VHF and UHF and does not have a GPS receiver that could provide Latitude, Longitude and accurate time at any portable location.
My first reaction was; would this be a disadvantage? I then decided if I wanted to work digital modes “accurate time” would be important. Further if I wanted to activate “National Parks” when portable, then an exact location would be imperative. It became obvious I needed a second transceiver to provide these features.

IC-2820H and 23A DC Power Supply

Looking around my collection of transceivers I realised that I already owned the solution. While not the latest model the ICOM IC-2820H ticked all the boxes with one minor drawback.
This transceiver, while being able to receive GPS signals, requires the front panel to be removed to gain access to the GPS antenna connector. While this is a simple process, the front panel cannot be repositioned with the GPS antenna connected. I solved this issue by making a bracket that supports the front panel while allowing sufficient clearance for cables. This mounting bracket is shown in the accompanying images.

GPS Antenna plugged into the IC-2820H

Without a doubt, once this small issue was resolved, this transceiver became the logical companion for the IC-7000.

Faceplate in place showing clearance for GPS antenna cable

With the selection of transceivers made, a number of the basic requirements could now be addressed.

The Antennas
Having defined the frequency range and the main transceiver identified, the question of antennas now became the focus. A quick “Google” search on the internet revealed a variety of possibilities.

With this in mind, I settled on an end fed “inverted V” supported at the centre by a 6m “Squid Pole”. The “Squid Pole” is held vertical by a “beach umbrella” stand as shown in the accompanying images. The ends of the “inverted V” are elevated using 3m fibre glass poles held vertical using angle iron support bases.

Antenna Pole Support System

Antenna Pole Supports

The “inverted V” is end fed using 1:60 UNUN transformer that raises the 50 ohm feed line impedance to approximately 3000 ohms that matches the impedance at the end of the “inverted V” quite closely. This ensures that the resulting SWR  across the 40 to 10 meter spectrum is under 2:1.
Note: I manufactured the 1:60 UNUN transformer and associated counterpoise from locally available Ferrite cores. The manufacture of these two pieces of equipment may form the basis for a future article.

60 to 1 Autotransformer and counterpoise.JPG

As the IC-7000 transceiver has 6m capability I manufactured a Halo antenna to provide horizontal polarisation, the polarity of choice for most 6 m operators.

In addition to the HF “inverted V” and 6m antenna, I added a Diamond X-510M that is 1.7 m long and provides dual band (2 m / 70 cm) Vertical antenna to facilitate the use of D-Star and FM repeaters if and when required.

The Antennas 40m to 70cm
These antennas are mounted on a single 3m x 25mm aluminium mast held vertical by a “star picket”.

Setting up the station
The station console is assembled in a “SKB 19” rack music case” fitted with two (2) “electrical cable tray” shelves.

GO Box Front of Case.JPG
As many of you would be aware, electrical cable tray is slotted. This feature of the cable tray permits an easy flow of air around the equipment thereby preventing the notorious hotspots within enclosures that have a bad habit of leading to equipment failure!
One of the good features of this type of case is the fact that the case comes standard with removable front and back covers that provide easy access to the equipment and good cross flow ventilation. In addition the front cover is 50 mm deep that allows the equipment to be located such that access to the transceivers controls is a simple process.

Back Cover Removed

Back of the console with cover removed

The pictures of the console show the ICOM IC-7000 transceiver at the bottom right of the console. This transceiver is mounted in a mobile cradle which allows good circulation of air around the unit during prolonged operation.
On the top left is the ICOM IC-2820H dual band, high powered, D-Star, FM transceiver that delivers 50watts on 2 m and  70 cm. This is an ideal unit for simplex FM liaison or accessing FM and D-Star Repeater networks on either band.

The unit on the top right is an MFJ-945E mobile antenna tuner. While not actually necessary, it provides a way to ensure that the IC-7000 transceiver is always presented with 50 ohms when connected to the “inverted V” antenna.

On the lower left of the console is a Manson SPA-8230 13.8 volt 23 amp regulated power supply. This unit has sufficient capacity to support the console if 240 AC power is available.

Faceplate replaced
I have also attached a label to the face of the power supply that provides settings for the tuner when using the “inverted V”. This has proved most valuable when requiring to quickly change to another band!

Polarity and OL Protected Supply

The system is designed run from a 12 volt Battery or 240v AC supply. Changeover is effected by a single switch on the rear of the console. The changeover switching system is designed to provide polarity sensing and overload protection for the regulated power supply or the 150 ah AGM battery. The regulated 13.8 volt power supply also provides a charging socket on the front for a cell phone etc., if required.

Power Source Change Over

In designing this changeover system I was determined to ensure it was simple. The regulated power supply, transceivers and auxiliary equipment are all permanently connected via their respective power connectors to the changeover system. The changeover system has a 12 volt battery cable with a heavy duty 50 amp  “Anderson plug” attached that provides polarity protection when connecting to the battery source.
A 240 Volt power cable can be plugged into the power supply, when needed.

These two cables can be coiled and stored inside the case when the back cover is in place.

Rear of the IC-2820 and Power Supply

The rear of the console provides ready access to the antenna connections on each of the transceivers.

Rear of the IC-7000 and MFJ-945E Tuner.JPG

The small die-cast box in the rear lower left of the console houses the ICOM CI-V Serial Bus level converter that permits computer control of the ICOM IC-7000 transceiver. The images of the front and back of the console provide support for the explanation of the equipment used.

The Utility Case

All of the support cables and feedlines are housed in a small utility case. The contents of which are shown in the adjacent image.

All that is required

Antenna feed lines
The ICOM IC-7000 provides two (2) SO-239 sockets on the back of the transceiver; one for 160 to 6 meters and the other for 2 m and 70 cm.
Because the “inverted V” only provides coverage from 40m to 10m then when 6 m operation is required, the HF antenna would need to be disconnected and replaced with the 6m feed line.
The swapping of feedlines is a very inconvenient and frustrating process and detracts from the enjoyment of operating.
To overcome this issue I added a Diamond MX610 Duplexer connecting its HF output to the feedline going to the end-fed antenna and Duplexers VHF connection feeding the 6M Halo antenna.

As a result of using the duplexer only three (3) coax runs are required with one for HF, one for 6 m from the ICOM IC-7000 and one for 2 m and 70 cm from the ICOM IC-2820H.
Each of these cables are labelled at the ends to aid simplicity when deploying the antennas.

The Power System
Having found suitable solutions for the issues considered, the next area to be focused on was the power system to support the entire operation. Central to the basic system is a 150 a/h AGM battery that is mounted in its own case. This case is fitted with overload protection and two Anderson 50 amp polarised plugs. This allows the console to be connected to the battery system without the fear of polarity reversal. The second plug allows 80 watts of solar panel to be connected to the battery system thereby enhancing the stations performance during sunny daylight hours.
During the night, this connection can be used to connect a multi-stage CTEK battery charger powered by any generator system; in my case a 2Kva Honda.
In situations where access to 240 volt AC power is available, the entire system can be changed over by the “flick of a switch” at the rear of the console (see images of the rear of the console) and plugging in an appropriate 240 volt power outlet.

Computer Support
To facilitate the use of Digital modes and the logging of contacts I have used a Microsoft Surface Pro Computer running Ham Radio Deluxe Software.
There are many other laptop computers that could be used but I just happened to have one of these units that performs very well indeed. While the Surface Pro has a battery that lasts for only 6 hours, not enough to last for most portable requirements, it does have the added advantage of having a power supply, which is designed to work with 240 volt AC and 12 Volts DC, so battery life is not an issue.
The Surface Pro computer has one drawback, it only has one USB port however a small USB hub solved the problem by providing multiple ports that allow a sound card interface and the CI-V interface to run simultaneously. The operating system for the Surface Pro is Windows 10 Pro making it quick to use and very responsive.

While portable, access to the internet is a desirable facility that provides the ability to connect to databases such as “Ham Call and QRZ”. Unfortunately this is not always practical unless you have access to a Pocket WIFI 4G router. These magical little devices are, in effect, a 4 G Modem and Wireless Router (802.11n) rolled into one. The device I bought outright, was a Telstra Pocket WIFI 4G Modem (most of the telco’s have a version of this device). These units have their own internal battery and will accept a prepaid SIM. These units accept routing of up to five or more computers using 802.11n WIFI. The battery life of the unit has proven to be about four hours (4 hrs) but this has not been a problem as the unit can be charged via its USB connection from the computer when required. The Pocket WIFI unit is very sensitive and provided you are in a cell phone network area, I have found it to be a real asset while portable.

This project has been a lot of fun to develop and operate and I hope it may provide a few ideas for anyone who has been contemplating HF portable operation but not quite sure where to begin.

 

 

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A Portable Satellite Station

 

With the successful launch of AO-91 and AO-92 there are now more than twelve (12) active Amateur Radio Satellites orbiting the Earth providing a variety of communication possibilities throughout Australia, New Zealand, South East Asia and the Pacific.

Having participated in satellite communication since the launch of Sputnik 1 in 1957, I have actively used most, if not all, the amateur radio satellites that have been launched throughout the years. In all that time I have confined my satellite operation to using my home station to great advantage. Articles elsewhere in this Blog describe some of my exploits.

Since retiring, my XYL and I are enjoying travelling especially in the National Parks throughout Australia with our 4X4 and Caravan. This activity has resulted in “ham radio” being confined to terrestrial communication. While enjoyable, it has resulted in satellite communication being “left at home” as the satellite station was hardly portable!

Over the years I have attempted to address this situation by using a variety of “hand-held” radios and antenna, with less than ideal results. With this history behind me I have decided that I need a portable satellite station to overcome this deficit in my Amateur Radio operations.

How To Proceed.

A search of the internet soon revealed that there are many portable satellite stations being used, with a mixture of equipment, by amateur radio operators around the world and I am sure a great deal of pleasure has been derived by the operators using their equipment. A great many of the solutions described use equipment that I don’t have and so I decided to design and build a system that focused on the equipment I had available.

twin-ft817.jpg

The Design.

In designing the system it became obvious that the system needed to be totally portable, easy to assemble and when completed, needed to be simple to use!

In order to achieve the system described I was determined the design must reflect the following:

(1)The total operation needed to be based on a battery power source complete with polarised plugs, polarity protection and the ability to have a trickle charge for the battery supplied by a small solar panel.

(2)The receiver and transmitter need to be frequency agile and computer controllable to compensate for “doppler shift”.

(3)The computer must be viewable in sunlight, have sufficient ports to control the receiver and transmitter, able to run software that provides satellite predictions , have at least six hours battery life and be capable of being recharged from the main battery source.

(4)The antenna must be light weight, simple to transport and provide a minimum of 10 dBd of gain on 70cm and 6 dBd on 2m.

(5)The antenna must allow tri-pod mounting with sufficient flexibility to change its elevation and azimuth angle and polarity.

(6)The receiver and transmitter must provide multi-mode (CW, SSB & FM) operation to allow access to all of the satellites that are available.

(7)The transmitter must be capable of providing a range of sub-audible tones that are required by a number of satellites to gain access.

(8)The dials on the receiver and transmitter need to be viewable while standing or sitting behind the antenna to facilitate tuning across the band pass of the satellite (a must for linear satellite transponders).

(9)The transmitter must be capable of a power output of 5 watts if the linear transponder satellites are to be accessed.

(10)The system should be supported by a “mode J” filter to prevent “desense” of the 70cm receiver by the 3rd harmonic of the 2m transmitted signal.

(11)The tri-pod must provide a “points-of-the-compass” scale and an “elevation scale” to facilitate the pointing of the antenna on the orbit of the satellite being tracked.

While these eleven (11) points may seem to indicate a complex design, it is the minimum necessary if maximum enjoyment is to derived from the portable satellite system.

I do however, acknowledge the system could be simplified if the object of going portable is to exchange callsign, name and report. While this may be acceptable for some very low orbiting satellites, utilising a single frequency, it would preclude the operator from using satellites such as AO-07, FO-29, CAS-4 and the XW-2 series, which offer a wide range of usable frequencies and modes (CW, SSB, SSTV , FT-8 etc) providing the operator with the time to enjoy a longer QSO.

It is not my intention to discuss operators individual satellite QSO preferences in this article, but rather to identify why I assembled my portable satellite station utilising the design outlined above.

Where to begin ?
As someone once said “lets begin at the beginning”.

In the design outlined above my first concern was the overwhelming desire to make the entire system battery powered.

The Power Source.
To this end I settled on a 26ah sealed battery. With a battery of this size, it provides the luxury of allowing the equipment I intended to use, to be left running for several hours without the concern of depleting the battery. In addition I decided to include a small solar panel that would fit into the case housing all of the portable. This unit can supply a 1A trickle charge for the main battery.

Having worked portable over the years I was determined that the reverse polarity would not be an issue and so I introduced polarised plugs and sockets for all connections from the battery. The accompanying images show how this is achieved.

The Power Source and Distribution System

As a double check, I included a polarity sensing distribution system that is shown in the attached images accompanied by its schematic.

The Transceivers.
The radio equipment I decided to use were two (2) Yaesu FT-817nd Transceivers that provide 5watts output in a multi mode format. These transceivers can be computer controlled, multi-band – multi mode VFO controlled transceivers with their own internal batteries. In addition their screens can be easily seen in daylight and can provide different colours of screen (this proved to be a decided advantage when operating the station as explained later). These credentials match the design criteria outlined in (2) above.

The Computer.
Chasing and communicating with satellites can be quite difficult without a computer and therefore I was determined to incorporate a small laptop into the design that could be viewed in daylight (non reflective screen), have its own battery that could provide at least 6 hours of operation, have as a minimum of 2 USB ports and be capable of running satellite prediction and control software. In addition the computer needed to be chargeable from a 12 volt source to facilitate operating for extended time periods.
My choice was an ASUS “EPC” running windows 10. The two plugs shown on the right hand side of the computer are USB ports controlling the Transceivers.

The Antenna.

Without question the major component of the portable satellite station is its antennas. Since all of the satellite operations require a UHF and VHF antenna it is vital that each of the antennas has sufficient gain to ensure (1) the successful reception of the satellite signal and (2) sufficient radiated power to allow reception by the satellite.


My solution to requirement was to build an 8 element UHF Yagi which provides a gain of 10dBd. The VHF Yagi has 4 elements mounted at right angles to the UHF Yagi providing a gain of 6dBd. Each antenna satisfies the link budget requirements for reception and transmission for most of the available satellites.

A Portable Antenna.

To facilitate portable operation the antenna needs to fit inside my 4X4 so it was obvious that the VHF elements had to be capable of being removed.

Portable Satellite Antenna

This process involves the VHF elements being mounted through a small aluminium channel (50mm long) and secured by a stainless PK screw. The channel has two additional holes drilled to allow two metal threads to pass through the UHF boom and fastened with wing nuts.

img_0138  img_0136

Enlarging the image will show the technique used. The reason there are three holes in the boom allow the head oh the PK screw to fit into the boom allowing the element to sit flat.
In the past I have used a technique that is simple and quick to assemble and dismantle.

Adding the last two VHF directors.

The VHF & UHF antennas were designed to be robust. The Yagi’s are based on a DL6WU design calculation and use 10mm aluminium tubing elements and a 20mm square aluminium boom. The antenna elements are mounted through the boom and are held in place using stainless steel “PK” screws.

The VHF & UHF driven elements use a gamma match for simplicity of construction.
The UHF feed line is connected using an “N” type socket while the VHF antenna uses an SO239 socket.

 

img_0140.jpg

This shows the UHF and VHF feed points

 

The antenna is using plumbing PVC pipe and fittings that facilitate easy tripod mounting while creating a balanced antenna. This allows the antenna to rotate on its “X” axis and be steerable in azimuth and elevation.

 

img_0142

Antenna mount made from Plumbing fittings and the elevation scale

 

Azimuth and Elevation Scales.
To simplify the usage of the antenna, there is a need for two support mechanisms
that help the operator to determine elevation and azimuth when the antenna is placed on its tri-pod.
In each case simplicity must be the key. The accompanying images show a simple compass and elevation system that allows the antenna to be pointed quickly and accurately. Both these scales were developed on the computer, printed and then laminated (weather proof!).
The elevation scale is a simple quadrant that has been glued to an aluminium bracket with its pointer made from a strip of aluminium, sprayed black and mounted using a metal thread.
The compass has a small hinge attached to the underside of the scale. The hinge was introduced to allow the legs of the tri-pod to be spread without effecting the compass. A Velcro band attaches to the compass to the tri-pod for stability. I use the compass app on my iPhone to determine north when setting up the tri-pod and once set, directions are easily determined.
The images show that the scales are easy to read and it is quite a simple matter to follow the satellite pass.

Antenna Feed-lines.

The feed lines are routed to the rear of the antenna to ensure minimal interference to the antenna radiation pattern. The cable type I elected to use is RG-214 coax, 3 meters in length, colour coded to simplify assembly.

Transceiver, Computer and Power distribution Mounting.

As with all portable operation, the positioning of the transceivers and the computer can make or break the entire operation. With this thought in mind, I decided to mount the two YAESU FT-817nd transceivers and the computer on tri-pods. To achieve this, I produced a mounting bracket that locks to the tri-pod legs. The attached images show how the equipment is positioned.
The computer sits on its own tri-pod and is positioned so the screen can be seen by the operator while adjusting the antenna.
The polarity protection and distribution system also clips onto one of the tripod legs.

Improving VHF Sensitivity.

A small VHF pre-amplifier has been added to the design. This pre-amplifier can be switched out of circuit when transmitting on VHF. In addition it can simply be left switched off.

img_0144

 

The amplifier has its gain set to 6dB and provides a noise figure of 0.1dB. A very valuable addition when working SSB through AO-07, FO-29 and the other larger satellites horizon to horizon.

Mode J Filter.

As outlined above the design calls for the use of a “mode J” filter. The filter is only active when transmitting on VHF and receiving on UHF. The filter is used to prevent the 3rd harmonic of the VHF signal radiating into the UHF receiver causing severe desensitisation when transceiving. This desensitisation can be so intense as to completely mask the satellite signal.
The simplest form of filter can be made using a diplexer that can be arranged to work as a low pass filter on VHF and a band stop filter on UHF. The VHF input of the diplexer is connected directly to the VHF output of the VHF transceiver and the UHF output of the diplexer is terminated in 50ohms. The configuration is shown in the attached circuit. The UHF output can be left unterminated however in practice I have found that terminating this output eliminates all traces of “desense” within the UHF receiver.

Arriving at the portable location.

Transporting the complete satellite station to a portable location is quite simple with all of the electronics housed in one case with the
antenna system seperate .
The antenna system comprises 2 tri-pods (one to support the antenna and the second to provide a mount for the computer), antenna mount and UHF antenna with its VHF elements removed. This makes it a simple process to store and transport the complete satellite station in the rear of my 4×4.
The assembly of the antenna system is simple as outlined earlier in the text.
The case houses the transceivers, transceiver mount with the UHF desensitised filter, VHF pre-amplifier, power cables, microphone, feed lines, USB interface cables, polarity protection system, headphones, battery cables, DC to DC charging system for the computer, the computer, solar panel and compass disc.

All of the cables are marked with coloured tape. The tape colours I used are orange for VHF and blue for UHF for no other reason than the Yaesu transceivers can reproduce these in their screen colours making assembly of the station very straight forward.
The image shows the open case and the  system components.

Making it all work!

While the portable satellite station can be assembled quickly and easily, knowing where to point the antenna and compensating for doppler shift requires another set of solutions. Thankfully the solutions can all be provided by the use of a computer with suitable software.
The software I decided to use is satPC32 ver 12.8d. I use this software in my home station with very reliable results. It has proved to be just as reliable in controlling the YAESU FT-817 nd transceivers for doppler shift correction and runs very well under Windows 10 on the ASUS computer.
I also run Orbitron ver 3.71 in radar mode. This software clearly shows the orbit of the satellite as it tracks across the sky making it very easy of point the antenna at the satellite.
NB; Orbitron is quite an old program and was written when Windows XP rained supreme. To facilitate its use with later versions of Windows make sure it is run in administrator mode to achieve full functionality.

Equipment and Software settings.

Equipment setting can make or break portable operation. It is important to make sure that all of the equipment and software are setup to “talk to each other” before going portable.

What are the variables that must be controlled?

The transceivers (VHF and UHF)

Frequency and mode will change based on computer doppler file in the tracking software

  • Frequency VHF (145.5 MHz) UHF (435.5 MHz)
  • Mode (FM, SSB etc)
  • Power (5 watts)
  • RIT (enable)
    Squelch (enable – NOT RF gain)
  • Control port baudrate (38K)
  • Headphone switch (enabled on side of transceiver)
  • Antenna port (rear so cables don’t trail across dial)
  • VFO (enable)
  • Battery charge time (10 HRs)
  • Screen colour VHF (orange) UHF (blue).
    Screen font (large enabled)

The computer

  • VHF USB port (enable IRQ 3)
  • VHF Port baudrate (38K)
  • VHF Port identification (orange)
  • UHF USB port (enable IRQ 5)
  • UHF Port baudrate (38K)
  • UHF Port identification (blue)
    (by always plugging the cables in the same port, the setup will be set for all subsequent operation)

The computer interface

CT-62 CAT interface (2 required, one for VHF and one for UHF) colour coded as described.

The Software
SatPC32

Make sure that the software is configured in the following areas. The “Help files” clearly outline the critical settings.

  • Observer profile (Call sign etc)
  • Grid square (based on portable location)
  • Radio interface (enable for transceivers being used)
  • Control Port VHF (enable 3)
  • Control baudrate (38K)
  • Control port UHF (enable 5)
  • Control baudrate (38K)
    Doppler file (each satellite to be used needs to be set within this file)
  • AMSAT name file (each satellite to be used needs to be set)
  • Tone frequency ( for each satellite to be used if required)
  • Prediction screen enabled (when, where and max elevation)
  • Screen size (W1-W5 as required)
  • Current Keps download

Orbitron

Make sure that all of the areas are filled in or the software will give erroneous.

  • Observer profile (Call sign etc)
  • Grid square (based on portable location)
  • Tle file (for each satellite to be used)
  • Not all satellites appear in the Tle file however if this file is edited to include the NASA Keps used by satPC-32 then the two programs will provide identical information.
  • (http://www.amsat.org/amsat/ftp/keps/current/nasa.txt)
    Keps download
    Switch to “Radar screen format”

I did it my way and it worked.

I know there are many ways to setup a portable satellite station and as I mentioned in the beginning, a search of the internet will always uncover other ways to solve this problem.

Building this portable satellite station has given me hours of pleasure and a great deal of satisfaction.

Thank you for taking the time to read this article. I hope I have included sufficient information to provide you with the incentive to build a portable satellite station and participate in this ever expanding frontier of Amateur Radio.

 

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Having Fun with Amateur Radio Satellites

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Field Days can be Fun

After enjoying a number of VHF UHF / Microwave field days in recent months, I decided it was about time I wrote a few words about the experience in the off chance that it may act as a catalyst for one or two of you to “give field days a go”!

This article is not intended to give a definitive solution to the topic of field days but rather to provide an exposé’ on how I went about assembling a field day station that has given me many hours of enjoyment.

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Arriving at a field day site.

Much of the detail relating to specific pieces of equipment that I have used in the field day station can be found elsewhere on this Blog!

To begin this exposé’ I think it is important to identify what was and has been the motivating force that has driven me to build my field day station. Put simply, I wanted a station that:
(a) covered a variety of bands within the class of field day eg.,(VHF UHF / Microwave),
(b) had antennae that provided adequate gain without being critical to point,
(c) was simple to transport,
(d) assembled easily (one man),
(e) was reliable and had dedicated equipment,
(f) provided a self contained power system (batteries, solar panels and generator)
(g) had an operating position that protected the operator from the elements,
(h) was a pleasure to operate in a variety of locations.

With these factors guiding my every step, I began what has been quite a challenging project!

The first step was to decide what range of frequencies I was going to provide for my portable field day station. From my observations of over fifty years of amateur radio, the field day activity in Australia is clustered into two areas of the spectrum – above and below 50 MHz. This article will only focus on 50 MHz and above with the highest frequency being 10 GHz.

The next step was to consider what type of antennae would be practical for each of the bands and making sure that the correct polarisation was available for the respective modes to be used throughout the chosen spectrum.

In Australia most of the SSB contacts on the various bands 50 MHz and above, use horizontal polarisation while FM contacts use vertical polarisation, so it was very important that if maximum contacts were to be enjoyed, attention to the polarisation issue was important.

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Mounting the 6 m Halo.
The antennae that I chose provide maximum flexibility without requiring me to be constantly adjusting the azimuth just to make contact. I also chose to use a YAESU variable speed, computer controlled rotator, that provides (all weather) azimuth adjustment from the operating position.

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Looking at some of the antennae.

The antennae that I have used are;
(a) 6 m Halo or 3 ele Yagi (horizontally polarized)
(b) 2 m Halo or 8 ele Yagi (horizontally polarized)
(c) 70 cm 13 ele Yagi (horizontally polarized)
(d) 23 cm 19 ele Yagi (horizontally polarized)
(e) 13 cm 600 x 400 mm Grid Pack ( horizontally polarized)
(f) 9 cm 900 mm off-set Dish (horizontally polarized)
(g) 6 cm 600 mm off-set Dish (horizontally polarized)
(h) 3 cm 300 mm prime-focus Dish (horizontally polarized)
(i) 2 m, 70 cm, 23 cm Tri-band Vertical (Diamond X-5000N)
(j). Active GPSDO Antenna (powered via coax feed)

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Another Antennae view.

Having operated in field days for more years than I wish to remember, the most critical part of the station has always been the mast which was and has been either too heavy for one man to erect or too light which invariably bent in the middle when attempting to raise it into position! With this in mind, I was determined to find a better way.

After considerable thought and research I was sure what I did not want. I didn’t want a mast that;
(a) attached to my car in any way,
(b) required pegs driven into the ground or what ever surface I happened to be parked on,
(c) needed more than one person to erect,
(d) relied on the “armstrong” method of antenna rotation,
(e) used my car to transport a variety of lengths of pipe and antennae,
(f) didn’t allow all of the antennae outlined above to be mounted on the same mast.

With all these thoughts and criteria buzzing around in my head, the gem of an idea began to develop! It soon became obvious – the best solution for my needs would be a “box-trailer” mounted system.

With the decision made, the system began with a 50mm steel angle-iron frame that could be slipped into the base of a 1800×1200 box-trailer and bolted to the base (this meant that it could be removed when not required for field days). Cross braces were then added to the base frame to allow a central ” gin-pole” to be positioned which had an internal pulley added to the top and tripod support braces to ensure stability. A winch was added to facilitate the raising of the mast using the gin-pole. The mounting for the mast rotator was accomplished by attaching a hinged mast stub at the base of the gin-pole. A piece of 50 mm angle was bolted to the gin-pole near the top which would assist with anchoring the mast bearing when the mast was in a vertical position.
The last requirement was the mast itself. It needed strength, but could not be too heavy; it must be capable of collapsing to form manageable “one man” lengths and be at least six meters in length when assembled. The final solution was a 50 mm scaffolding tube that was cut in half and sleeved. The sections were pushed together and bolted when assembled. Cross arms were added to the bottom section for mounting the Microwave Antennae and Transverters. A small offset sub-mast was added to the top section to mount the GPSDO antenna.

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Raising the mast.

After manufacturing all of the components and assembling the system, one final problem presented itself. How was I going to carry all of the antennae and mast sections safely?
The accompany photographs show how a series of mounting brackets have been added to the assembly to facilitate the transporting of all of the antennae. Labels have been added to ensure that all of the components are returned to their respective locations. Yes I could have just bundled all of the antennae and lay them in the trailer but by having a specific location for each component, nothing is forgotten and most importantly, nothing gets damaged!

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Labels are in red. The photo also shows the mast bearing being bolted into place.

The operating position in a field day station has always been an issue for me as it seems to be the forgotten ingredient in what can be a well planed expedition into the field. I know I have been guilty of thinking I will just take a small table and that is all I will need. While I have managed to do this on a number of occasions, I have had some monumental failures with tables collapsing resulting in damaged equipment etc. Having gone to the trouble of working out a suitable antennae system, I decided it was time to have an operating position that was easy to setup, functional and sturdy.

During my frequent visits to the hardware store, while constructing the antenna system, I became aware that the “Stanley Tool Company” was selling a “Fat Max” toolbox with wheels, that has three major storage areas that could adequately store all the cables and minor components for the portable operation and also act as a console for mounting the transceivers. In addition, the lid of the toolbox could be used as a operating desk with the addition of a three-ply insert and a support strut. The accompanying photographs show the toolbox in operation.

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Fat Max from the back.

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Fat Max from the front.

With the system components completed, the next area to be addressed was the power system. When operating portable, I usually rely heavily on battery power that is separate from the vehicle battery. In the past I have tried to use the vehicle battery as part of the power source with disastrous results ( modern vehicles and flat batteries don’t mix)!
I therefore decided to use 2 x 150 ah AGM batteries supported by 160 watt Solar Panels for daytime operation. This decision has proven to be most satisfactory with an average of 12 amps per hour being fed back to the batteries under good sunlight conditions. During the evening however, battery charging is achieved by using a Honda EU20i, 2 Kva generator that feeds a CTEK 25000 series Smart Charger that is very effective at keeping the batteries fully charged. The Honda Generator is extremely quiet acoustically and electrically. These factors, coupled with good fuel efficiency, have proven to be an excellent addition to the Field Day Station.

Weather conditions are a critical factor in the field especially when considering operator comfort and over the years I have tried a variety of shelters / tents etc., however I have never been totally happy with the amount of equipment / effort that was required to setup a suitable shelter. What I really required was a shelter that was attached to my vehicle, that I could assemble by myself and provided all weather protection. The Supa-Peg RV Awning that is manufactured in South East Queensland, matched all of my requirements and has proved to be an excellent all weather shelter that can be setup in a matter of minutes.

No field day operation would be complete without some method of storing a cold drink, milk and food. This has been achieved by using a WAECO 35 L – 12 volt fridge/freezer that has done the job very well indeed.

Well I hope this article may have provided some ideas for one or two of you who are thinking of going into the field. This project has certainly made “Field Days” fun for me.

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Microwave Activity Day at Mt Gravatt – October 2012

The Brisbane VHF Group organized a very successful Microwave Activity Day on the 28 October 2012.

Prior to the day numerous stations had indicated that they would be in the field and operating on a number of the Amateur Radio Microwave Bands. The locations for these stations centered on South East Queensland and into northern New South Wales. It was also identified that the activity would begin at 0900hrs local and continue until mid afternoon. It had also been established that the first hour would be dedicated to 23cm and 13 cm. After 1000hrs all Bands would be used. The Brisbane 2 meter Repeater was to be used for liaison after 1000hrs with 146.550Mhz simplex being used as a backup. It was also suggested that checking the VK Logger to ascertain the locations of the various stations and the actual contacts being made would be an advantage.

With all these factors in mind it became obvious that to participate successfully in the day I needed to setup my full VHF, UHF & Microwave field day station.

The Microwave Bands to be covered were 23 cm, 13 cm, 9 cm, 6 cm and 3 cm using individual Transverters and Antennae.

The IF Transceiver for all the Transverters is a Yaesu FT817 ND that is mounted in the central console. Switching to the required Transverter is accomplished by rotating the silver knob in the centre of the console. A detailed explanation of this system is given elsewhere on my Blog.

Liaison was accomplished using the ICOM IC7000 Transceiver with a Tri-band vertical antenna (2m, 70cm & 23cm) located at the top of the mast.

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The centre console.

I used an Apple MacBook Air laptop computer to interface with my Thunderbolt GPSDO to ensure frequency accuracy of all the Transverters and the laptop also allowed Internet connection via a Telstra 3G WIFI Hotspot Modem to access the VK Logger.

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The DC Power for the entire operation was supplied by a 12 volt 150 Ah AGM Battery. The power cables all use Anderson 50A polarized plugs to feed the equipment.

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GPSDO and power distribution.

As with any portable location a covered operating position was required and this was provided by a rollout awning from the vehicle.

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The awning made operating very comfortable.

The day started under overcast skies but it soon became apparent that it was going to be a fun day and the effort involved in setting up the station was worth the time involved.

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About to setup at the Mt Gravatt site.

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Assembling the mast.

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Running the cable looms.

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About to raise the Mast.

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Mast raised and locked. The antennae shown from the top of the mast are the Tri-Band Vertival, the GPSDO, 6m Halo, 70cm Yagi, 2m Halo, 2.4Ghz Grid-Pack, 23cm Yagi, 3cm 30cm Dish, 5.7Ghz 600mm Dish and 3.4Ghz 900mm Dish.

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In contact on 3.4Ghz.

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All working and performing well.

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In QSO while monitoring the VK Logger.

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It’s 1500hrs and time to pack up and head for home – a great day!

The day was very successful and a most enjoyable time was had by all. I was fortunate to have all the equipment perform as expected and I made multiple contacts on all bands.

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The Centre Console for a Microwave Portable Station

Thank you to all of you who have asked questions about my Portable Microwave Station. I hope the emails I have sent have gone some way to answering the many and varied questions raised. There has however been quite a number of questions asked that have centred on the main operating position and specifically how the Microwave Transverters are controlled from the operating position. This post will attempt to describe how I went about solving this issue and how I have assembled the HF, VHF and UHF transceivers that I use to ensure maximum operating efficiency while providing maximum protection for the equipment.

This is a view of the Centre Console and Microwave Transverter Selection Control

The centre console is built into a “roady” 19″ rack case that has been divided into two sections using a central divider on to which has been mounted a series of supports that hold the Transceivers.

Beginning at the top left is a YAESU FT8800R Dual Band (2m / 70cm) FM Transceiver. Under this Transceiver is a YAESU FT817ND (HF, VHF, UHF) Multi-Mode Transceiver that provides the RF drive and IF/PTT for the Microwave Transverters. The selection of which transverter is to be active is controlled by the control knob at the top centre.

Below this transceiver, still on the left hand side of the case, is an ICOM IC1200 (23cm) FM Transceiver. This transceiver and the FT8800R are connected to a Triplexer system that feed a Diamond Vertical that is located at the top of my portable mast. Primarily these two transceivers are used for liaison when operating portable. The YAESU FT8800R has the additional feature that permits it to operate as an FM repeater if required.

On the right hand side of the case is mounted an ICOM IC7000 (HF, VHF, UHF) multimode Transceiver that delivers SSB on all the band up to and including 70cm. This transceiver produces 100 watts PEP on all bands up to and including 2m and 75 watts PEP on 70cm.

Below this transceiver is an ICOM AT180 Automatic Antenna Tuner that operates up to and including 50 Mhz. This unit allows for tuning out a small mismatch when transmitting across the various bands.

This is the back panel that has to catches that lock it in place.

The console has front and back covers that totally enclose the equipment when not in use. The case is made from very robust material and therefore has the potential to standup to the rigors of portable operation.

This is the Front Cover which has clips on each side that holds the cover to the main case.

In addition access is also gained to the remote transverter connections that are positioned in the centre rear. This switching system is connected to the front selector switch using an extension shaft.

There are two connections on the to the remote switch, the one on the left provides 12volts DC to control the “Relay Switching Tree” and the second at the base is a 7 core cable connection that provides relay control of the relay tree.

The rear of the console with the remote transverter switching system in the centre.

On the lower lip of the case there are two pop-rivetts that support a small aluminium bracket that is used to anchor all the external cables using “velcro ties” thus removing strain on all of the connections.

The central bar that can be seen running across the rear of the box is an earthing bar to which all of the Transceivers are connected.

 

 

The completed Relay Switching System.

The seven core cable that is connected to the rear of the console is 10 metres long allowing the centre console to be placed in a convenient location well clear of the portable antenna system.

As shown in the photograph, the relay tree provides six (6) outputs for connecting to the Transverters. When active, a green LED is lit signifying the active output connection. Each connection provides an IF connection back to the YAESU FT817ND when receiving. In the transmit mode RF is sent to the selected Transverter with the PTT voltage sent to the Transverter via the centre conductor of the coax.

The following image shows the interior of the relay unit.

The interior of the relay switching system.

This view shows the six (6) relays and associated interconnections. The relays are labeled to assist in identifying what their role is in the overall operation.

The connector on the left hand side of the box accepts the RF, PTT and IF connection from the Transceiver.

The connector on the right hand side allows the seven core cable to connect to the relays.

Relay Assembly prior to wiring!connector on the right terminates the seven (7) core cable from the central control switch on the main console. In reality I use 8metres of cable in my portable installation.

The following images show the various components of the relay system.

The relays were positioned into cutouts in the double sided PC board to allow ease of assembly and to provide a ground plane that provides a low impedance grounding system for all of the components.

All the components for the remote switching system.

The enclosures used for the relay system are die-cast boxes that provide easy assembly and good protection for the components.

The system works well and makes the process of switching from microwave band to microwave band a very simple process. The LED’s positioned at the centre console and at the remote relay tree, make it a simple process to keep track of which transverter is active.

From an operational point of view, the system is very convenient and simple to use and makes the action of switching from band to band a very simple process!

I hope these few words and the accompanying images provide an insight into the way a central console and remote switched transverters can make portable operation more enjoyable!

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Mounts for Off-set Dishes

A number of questions that I have received have prompted me to publish the following images that show a close up of the Tri-pod Dish mounts that I used on 3.4 and 5.7Ghz.

Another View of the Off-set Dish Mount

The assembles were constructed using galvanised post stirrups that are available at a number of hardware stores.

Dish Mount for 9cm Off-set Dish

The stirrups were bent to produce an angle of 68degrees from the horizontal or if you prefer the reciprocal 22degrees from the vertical. This angle was then reinforced by inserting a gusset into the open end. I could have weldered the gusset but decided that the bolted gusset gave me a little more flexibility as some dishes  require a 65 degree angle.

These angles ensure that the  focal point of the dish points to the horizon.

There a number of anticles on the internet that discuss how to calculate the angle that is required for specific types of dishes.

3.4Ghz Dish Mount

I am sure the creative among you have other ways to solve this problem but this method worked for me.

The whole assembly is bolted to the try-pod using a 5/8 whitworth galvanised bolt that is usually supplied with this type of tri-pod.

In using this method the Dish mounting the mounting pipe for the dish is set at the correct angle to mount the off-set dish.

I hope those who are attempting to use this type of tri-pod are able to gain some ideas from these images of the solution I used to good effect.

Posted in Microwave | 3 Comments