QRP - Low power operation
It is generally accepted that 5 watts output or less constitutes QRP operation. This may not seem like much power when compared to 100 watts which the majority of HF transceivers operate at. In real terms it equates to a reduction in approximately 2 's' points on the receiving station's signal meter.
100 watts received at signal 9 5 watts received at signal 7
Under the right conditions worldwide communication is possible on the HF bands with low power. There are many hams who only operate QRP. There is more of a challenge involved and arguably more skill required, there is also less chance of causing interference to nearby electrical equipment.
Some modes of operation lend themselves to QRP operation more effectively then others. The most 'famous' being morse code or CW as it is also known. CW signals can be copied in noisy conditions and at low signal levels - it's much easier to recognise morse tones that it is to understand a voice signal when conditions are poor.
Morse code is no longer an internationally recognised means of communication as satellite communications now tends to dominate. It does remain very popular with amateur radio enthusiasts and morse code signals can still be heard in the HF spectrum originating from commercial operations around the world.
Learning CW is great fun too, my current favourite way of doing this is online: http://lcwo.net/
It's free to register and you can track progress whilst learning the different characters. You'll soon be in a position to recognise morse characters on the bands - don't be discouraged by the incredible speed some operators sent at. There are plenty of slower transmissions on 30 / 40m bands.QRP operation is possible using simple and portable power sources such as sealed lead acid batteries or nicad / nimh packs. There are a number of radios which are equipped to house battery packs;some of which are shown below.
Elecraft KX-1 Possibly the ultimate in low power consumption, battery powered portable CW only transceivers. Options include up to 3 band modules and auto ATU.
The best selling of all QRP / portable transceivers. Covering 160m to 70cms including all amateur bands inbetween - it will also receive between the amateur bands. It's a similar size to a paperback book, is self contained with an integral battery pack and is compact enough to take more or less anywhere.
I think it's fair to say that the FT817 has revolutionised portable / QRP amateur radio operation. See the hundreds of reviews on eham net:
There are several yahoo egroups dedicated to the FT817 which share useful information:
There are many aftermarket options available too, including filters and high capacity battery packs, some of the best being available from W4RT:
I have fitted the W4RT 'one big punch' speech processor into the mic housing - this makes a significant improvement to the transmitted audio - the manufacturer claims a 5db increase. I have also installed the Collins 2300 Hz SSB filter, this improves the transmitted audio further and improves the receiver performance.
This is an excellent HF/6m transceiver with 10 watts output and a very useful built in ATU (antenna tuner). It's roughly the same size as the IC706 range and has a good sized display and controls - this may be seen as an advantage over the 817. It does not have 2m and 70cms or an internal battery.
There are some great optional extras available from Icom. One being a versatile back pack which houses the transciever, the detachable front panel, battery and user supplied antenna. This is the pack I use with my FT817ND. There is more information on this setup below.
This is an under-rated transceiver, the performance by far outstrips its visual appeal.
I was surprised by the good quality of the received audio and the selecivity of the receiver. The transmitted audio could be described as outstanding, see my detailed review from eham.net below:
"I picked up the 20m version of radio 2nd hand complete with the CW module on ebay for less than the cost of a 10m multimode. I don't find the physical appearance or the build quality inspiring - however the performance is.
During tests between my FT 897, TS 480 and MF9420, my transmitted audio reports were better on the little MFJ - every time. It was reported as being equally as loud as my unprocessed 897 at 50 watts.
(I have since resolved the muddy audio reports on the aforementioned with an Astatic teardrop mic)
The receiver is also very good in terms of sensitivity and selectivity - you do have to be precise with the tuning however.
It's perfect for a travel / backpack radio - small, lightweight and not too much of a financial loss if something terrible happens to it.
Strongly recommended as a second hand buy, or a discounted new buy - QRP radios have evolved and are more prolific since this first went into production - today's UK pricing is high compared to fully featured radios such as FT 817 and IC703"
Portable / Backpack Operation
This mode of operation has increased in popularity recently with models such as the FT817 and IC703 being released. There have also been significant steps forward in battery technology making compact portable operation possible. Backpack operation is generally QRP due to battery capacity and the physical limitations on how much equipment can be carried.
Summits on the air - SOTA is an increasingly popular scheme which combines radio operation with hillwalking and adventure. For more information see link below:
Half the enjoyment of portable operation for me is being outdoors in the countryside.
The best theoretical location for HF portable operation is near the sea. This could be on a beach taking advantage of the salt water's conductivity to enhance your radio's signal. Alternatively on a hilltop with the sea in view, so that the radio waves can travel in that direction unimpeded, and even reflected by the sea.
If a coastal location is out of the question, the next best alternative is as high as possible with an unobstructed view of the horizon and as far away from habitation as possible.
The height ensures your radio signal reaches the horizon at a low angle resulting in fewer hops before it reaches a DX destination. Being far away from habitation means that you are less likely to receive man made interference from cars, tvs, computers etc - it's highly unlikely that you will be causing anyone interference with QRP.
I generally operate on 20m or 17m when I am portable and a number of simple antennas can be built for a few £ which can out perform more expensive antennas commercially made antennas. My recomendations:
QRP / Portable antennas
1) Resonant 1/2 wavelength dipole for band of operation fed with RG-58 or equivalent 50 ohm coaxial cable.
The equation to calculate a dipole antenna length is:
wavelength = 468/ Frequency
If the dipole is in an 'inverted V' configuration try:
wavelength= 464/ Frequency
If you wish to operate two bands such as 20m and 17m you could try a fan dipole. This is simply two dipoles attached to the same feedpoint.
2) 44 foot long doublet fed with open wire to a tuner, this is a multiband antenna which can be used on any frequency between 40m and 10m (maybe 6m too?). It's very lightweight and compact, but you will need an ATU. http://www.cebik.com/edz/aledz.html
3) If you don't have available space to erect either a dipole / doublet antenna, you may wish to try a vertical antenna with radials. If the antenna is physically shorter than 1/4 wavelength, it may have reduced efficiency compared to a full size antenna. That's not to say that it will not not work well. There can be advantages over a dipole which is installed at less than 1/2 wavelength high as the vertical antenna's angle of radiation will be lower resulting in better theoretical DX operation.
It's important to note that a 1/4 wave antenna should be fed against an earth - it is common to use 1/4 wave wire radials to provide an earth. The more radials you can deploy the better, however an antenna will still work with a single wire radial and may favour some directivity in the direction which the wire is placed.
I have used a diamond HM-6 multiband antenna connected to the rear antenna port of my ICOM 703. 4 X radials were connected to the earth screw on the radio and I used the internal tuner to achieve a match. I operated portable from a coastal hilltop in Cornwall (2003) and had QSOs with France, Russia, USA, Spain and Ukraine. This was achieved with 10 watts output and power provided by Yaesu battery packs (from FT 897).
QRP portable from Lanzarote as EA8/M5TAW November 2007
Our trip to Playa Blanca in Lanzarote was planned as a family holiday even though I had hopes that there would be a few spare minutes here and there to explore the HF bands. Luggage space was at a premium so I decided to travel light and take the following:
1) Yaesu FT817ND - with Collins 2.3 Khz filter, OBP speech processor in mic housing
2) Switch mode PSU for radio
3) Superantennas MP-1 - with supplied mount and worm clamp
4) Various resonant 1/4 wave radials for 20 and 17m and 50 ohm coaxial cable
Our hotel room was on the first floor out of a total of four, I estimate we were approximately 20 metres above sea level. There was a good view out to sea in a southerly direction from the Island, however the northerly view was obstructed by the higher floors of the hotel and beyond that the volcanoes.
The balcony was surrounded by metal railings which were absolutely perfect for mounting the MP-1 antenna. I used the antenna with the railings as a counterpoise and was able to tune the antenna to provide a zero SWR reading on the 817's meter.
In order to tune the antenna, I first adjusted for maximum received noise on USB and then set the transceiver to FM so that I could key with a carrier to check the SWR reading on the radios built in meter. The antennas's coil was within easy reach, so with the radio back in receive mode I shortened / extended the coil, re-checked the SWR as many times as necessary to achieve resonance - this process took no more than a few minutes.
In an attempt to improve the ground plane efficiency I added 2 X 20M 1/4 wave radials at the base of the antenna mount. In reality I doubt that the radials being 1/4 wave lengths on 20m was of significance as the railings acted as a very random length ground plane. In retrospect it would have been interesting to isolate the mount from the metal railing and operate with the resonant radials.
I generally spend more time listening than transmitting and my operations were limited to week days which are generally quieter than weekends. However I did listen to some good QSOs from countries which I have not heard from my home location with much bigger antennas!
The first interesting contact was was a South African station coming in at a steady signal 8. He was in QSO with east coast USA so I was hearing him off the side of his yagi. I have never heard any South African stations from my home location (with 6 or so years of operation on HF). There was a large pile up from the USA with most stations coming in at signal 7, so I did not attempt to contact him.
The second interesting contact I heard was a Spanish EA1 station calling CQ long path Pacific. I hear so many stations from home calling CQ Pacific, but again never hear the responding stations. This time I heard a VB8 station return from Taiwan, he was signal 3 and prefectly readable.
I listened to many other QSOs from Europe and USA and made contacts with France, Greece and Spain in what limited time I had.
I think that these results speak more about the antenna than they do about the FT 817 which as far as I'm concerned has proved itself. I have previously run comparisons under weak signal conditions on the HF bands between the FT817ND and my MP1000MP - there was nothing that the 1000MP could copy that the 817 could not.
Overall the MP-1 has met expectations. It is sufficiently well constructed for portable operation, is small enough for easy transportation, it should not attract unwanted attention and it seems to perform very well. My tests are not scientific and I did not make any comparisons during my week of operation. For more detailed test results I recommend viewing the HFPACK website where they have compared a number of portable antennas in a more scientific manner:
In addition, the MP-1 is great for experimentation. All threaded elements are standard 3/8th, so it's possible to change the base section for a longer one to improve efficiency - a Hustler M01 base section for example. Similarly one could change the top section for one of MFJ's longer telescopic whips (MFJ-1956). Either of these modifications will improve efficiency, more so on the lower HF bands.
Portable operation from the UK
I prefer HF portable operation in the summer months for several reasons. The most important from an operation point of view is because the higher bands are generally open for longer. In addition the days are longer with more daylight and the temperatures make operation more enjoyable.
Portable operation falls into two categories for me. The first category being portable operation from the home QTH in the garden. This enables me to experiment with different antennas and generally relax in familiar surroundings. I am unlikely to make any new ground breaking contacts compared to the base station simply because I have bigger permanent antennas and more power available with the base station. However I do still enjoy the challenge of low power operation.
The second category is operation from locations which are likely to provide better results than from the home QTH. Such a location is likely to be coastal or elevated with minimal obstructions.
I have operated at a number of coastal locations with low power and good success, see below:
Beachy head is located to the south of Eastbourne and is at approximately 100m above sea level. Access is easy by car and there is generally plenty of car parking space. I have operated with my FT 817 on battery power into a Diamond HF-20FX mobile whip which is 1.3 m long. This is a relatively small antenna which in theory will not be very efficient compared to a full size 1/4 wave whip. I'd be surprised if more than a few watts of power were radiated - however the band was full of strong signals and I was able to work into Luxembourg and Spain with good signal reports.
I believe this success should be attributed to this location being elevated and coastal.
Portloe is in the far south western part of England in Cornwall with Tregony being the nearest good sized town. It is located in the countryside and is accessed by a number of minor roads. I stayed in the lugger hotel which has to be the most relaxing hotel I have had the pleasure of ever staying in - highly recommended.
There are some good coastal walks from Portloe which take you up onto the cliff tops. It was from here that I operated in 2003 with my IC703 and Diamond HM-6 mobile antenna.
This setup was carried in the Icom LC-156 backpack with Yaesu FNB battery pack and head unit separation kit. The antenna was mounted the the radio's rear antenna port and 4 X resonant 1/4 wave radials. More info to follow...
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