Power
A QRP set up is very easy to realise , but a manageable QRO set up requires some additional thought, namely weight of the power supply. My intention was to have a 100W station that I could take into a field and run for a reasonable amount of time. Battery power is the obvious source, but the radio I would use (an Icom-706) hates low line voltage (and demonstrates this by drifting in frequency) and also draws 2A on receive. A large sealed lead acid battery is not cheap, is heavy, and requires charging frequently. Fortunately, I already had one of the best small generators available, the Honda EX7. This is extremely quiet, more so if it is placed downwind of the operator. With a dry weight of about 12kg it is not too heavy to carry, has a nice handle and will run the station all day on one fill of petrol. This compares well with the weight of a big SLA.
Radio Crate
The idea was to walk into a field and operate as soon as possible, without having to return to the car for additional equipment. The make this easy, the IC-706IIG, SEC1223 PSU and MFJ 901B ATU have been bolted into a aluminium frame, which provides all round access for servicing, additional connections (like digital I/O and audio), or plugging in the morse key (which didn't make it into the photo!). All wiring is contained in this crate so all the user has to do is put power in and take RF out. The OPC-639 EMC filter (packaged with the 706 for the EU market) is installed within the frame as the extra filtering is sometimes beneficial when running from a rough generator. The frame protects the equipment on all sides (nothing projects) and it can be used horizontal or (far more easily in the field) vertically. The head of the '706 can be separated from the crate and taken somewhere more comfortable if required. The crate is also ideal for emergency or demonstration use as it can be up and running in a few seconds - and nothing gets forgotten!
QRP
There are many times where taking the radio crate and generator is just not practical and then the QRP setup comes into its own. Running on 10 AA batteries the Small Wonders Labs DSWII-30 provides a good 5W signal on 30m - an excellent band for QRP CW (especially if you don't like contests!). The DSWII is fitted with the Jackson Harbour Press replacement 'brain' which provides many additional features like finer tuning of the DDS oscillator and a useful memory keyer function.
Teamed up with a palm mini paddle key and a homebrew end fed half wave tuner (a simple LC network) makes for a highly portable radio system. The light weight of the QRP system is ideally suited to a small soft kite, such as a parafoil. With this system one can play radio virtually anywhere, and if there is no wind then a tree of fishing pole can be used as an antenna support.
For the ultimate in portability it is difficult to beat the kit biult Elecraft KX1. The radio was designed specifically for ultimate portability and draws only around 35mA on receive, so a set of AA batteries can last a weekend. My KX1 is fitted with all the options and covers the 80m, 40m, 30m and 20m bands. It has an internal automatic ATU. The KX1 also houses 6 AA batteries (preferably lithium) as standard and the Elecraft bolt on paddle means that it can also be used hand-held. This is a big advantage as it can easily be used pedestrian mobile using a small kite.
The photos below show my KX1 station , housed in a virtually indestructable and waterporoof Pelican Peli 1060 case. The station comprises the KX1, its paddle key, earbud headphones and a 28 foot antenna wire and 16 foot counterpoise wire. The antenna tuner will tune this wire on 40m, 30m and 20m bands, for 80m a much longer wire is required, such as te one used with the endfed half wave for 40m. Of course, this radio works extremely well (on a single band) with the endfed tuner shown on the antenna page .
The closed Peli - box containing a complete HF station.
The station unpacks very quickly from its protective case, the antenna wire (blue) can be seen connected on the right hand side and the counterpoise wire (grey) is also just about visible.
Finally the KX1 in use.