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!
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.
Setting up the station
The Power System
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!
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.
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!
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.
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.
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.
Without a doubt, once this small issue was resolved, this transceiver became the logical companion for the IC-7000.
With the selection of transceivers made, a number of the basic requirements could now be addressed.
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.
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.
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.
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.
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.
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.
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!
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.
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.
The rear of the console provides ready access to the antenna connections on each of the transceivers.
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.
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.
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.