What Actually Goes in a Field Kit

A portable station is not a small station. It is a set of arguments about weight, and every item in the bag has to win one. The version of the kit you assemble at the kitchen table is always heavier than the version that survives three trips, because the kitchen table has no opinion about carrying anything uphill in the rain. What follows is what tends to be left after the trimming, and roughly what it weighs.

The decision that sets every other one

Transmitter power. Not because of what it does on the air but because of what it does to the pack.

Five watts of CW draws something like ten to twelve watts from the supply, which is under an amp at 12 volts. Two hours of operating at a realistic thirty percent key-down, plus receive current the whole time, comes to around one amp-hour. A four-cell lithium iron phosphate pack of three amp-hours holds about 38 watt-hours, weighs roughly 400 grams, and will do that three times over before it needs a charger.

A hundred watts draws something over twenty amps key-down. The same two hours needs around fourteen amp-hours, close to two kilograms of battery on top of a radio that is itself two kilograms rather than four hundred grams. So the choice is not between five watts and a hundred. It is between a kilogram of kit and four, and the on-air penalty is about two S-units. Decide that first and the rest follows.

The weight budget

Radio

A multiband CW transceiver in the five to ten watt class runs roughly 300 to 700 g. Single-band kit radios go under 200. The difference in the pack is small; the difference when a band closes is not.

Battery

Around 400 g for a 3 Ah four-cell LiFePO4 pack, which is a full day of CW. Anything bigger is a decision about power you have not revisited.

Antenna

An end-fed half-wave for 40 through 10 metres — 20 m of thin wire, a 49:1 transformer, a winder — comes to 200 to 300 g with counterpoise.

Feedline

Five metres of RG-316 or RG-174 is 50 to 80 g and costs well under half a decibel at HF. The same length of RG-58 is 200 g. Take the thin stuff.

Support

A throw weight and line is 80 to 150 g and needs a tree. A six-metre pole is 400 to 600 g and does not. Which is dead weight depends on where you go.

Key

A small paddle is 40 to 150 g. Whatever it weighs, it is not enough to stop it sliding, which is the real problem and is solved separately.

Audio

Earbuds, 20 g. Better than any speaker you can carry for pulling a weak signal out of wind noise.

Log

A small notebook and two pencils, 60 g.

Everything else

Cables, one or two adapters, cord, tape. 150 g if you are disciplined and 600 if you are not.

That is somewhere between 1.5 and 2.5 kg for a station that will work across an ocean on a good afternoon. The bag and the non-radio kit — water, layers, food, first aid — will outweigh all of it, and should.

The antenna is where the over-engineering happens

An end-fed half-wave has taken over portable operating for a good reason: it is fed at one end, so the radio sits with you and the far end goes up a tree, and a half wave on 40 metres is usable on 20, 15 and 10 as well. One wire, four bands, one support, no coax run to speak of.

A linked dipole is lighter still with no transformer loss at all, but you have to walk to the links to change band, which in practice means you change band twice and then stop. A short loaded whip is the lightest option by a distance and gives up real signal to get there — fine for a quick activation, frustrating for a session.

Whatever you pick, what decides its performance is how high the wire goes, not what kind of wire it is — as true on a hillside as at home, and covered properly in the antenna dispatch. A throw weight and thirty metres of light line weigh about as much as a chocolate bar and routinely buy four or five decibels that nothing else in the bag can match.

Power, in slightly more detail

Lithium iron phosphate is the right chemistry for this. It is more tolerant of abuse than the higher-density lithium cells, it holds a flat voltage through most of its discharge so the radio sees a steady supply almost until the end, and four cells in series sit at 12.8 volts nominal, which is what a 12-volt radio wants.

One caution worth reading the manual for: a fully charged four-cell pack comes off the charger at around 14.6 volts and not every small radio accepts that. Check the maximum input voltage before you connect anything.

Two more things the cold does. Capacity falls noticeably below freezing, so a pack that lasts all day in summer will not in January. And lithium cells of any chemistry should not be charged below freezing, which matters if you run a solar panel in winter. Keep the battery in a jacket pocket rather than in the snow beside the radio.

The key, and the problem nobody anticipates

A portable paddle weighs almost nothing, which is the entire difficulty: the first dash launches it across the rock. Everything else about portable keying is downstream of anchoring the key. Magnets on a steel plate, a thigh strap, hook and loop onto the radio, a flat stone on the base — all of them work, and none of them work if you did not bring the part.

There is an argument for a small straight key in cold weather that gets made less often than it should. Gloved fingers are clumsy at the fine side-to-side motion a paddle wants, and a knob you can hit with the whole hand is more forgiving. Your sending will be worse and the contacts will still happen. If you are undecided, the three key types are compared here.

Logging: paper wins

A pencil writes in the rain, in the cold, upside down, and does not run out in a way that surprises you. Ink pens quit below freezing. A phone screen is unreadable in bright sun, unusable with wet fingers, and is also your map, your clock and your way of calling for help — spending its battery on logging twelve contacts is a poor trade.

Write the callsign, the time, the band and the two reports. Nothing else. Transcribe it at home. Anyone who has tried to type a callsign into a phone while a station repeats it at 22 words per minute only tries it once.

Things people carry once and never again

A separate SWR and power meter, when the radio has one built in. A second antenna for conditions that never materialise. Spare coax. A laptop. A camp chair and folding table, both of which lose to a foam sit pad weighing eighty grams. A battery sized for a hundred watts, on a day when only CW got used. A soldering iron. A bag of adapters, nineteen of which stay in it forever. A tripod mast carried through a forest. A second radio, in case the first one failed, which it did not.

The pattern is consistent: nearly everything on that list is insurance against a failure that has never happened, bought at a weight you pay every single trip.

Things people forget once and never again

A headlamp, because activations run past sunset and packing a wire antenna in the dark is miserable. Insulating tape and a spare connector. Something to sit on and something to keep the rain off the radio — foam and a bin liner, under two hundred grams together. Enough cord to tie the far end off somewhere other than where you first aimed. Gloves you can still send in. Water, layers and a way to tell someone where you are, which is not radio kit and is the only non-negotiable part of the list.

And a card with your planned frequencies and times. Standing on a summit trying to remember which end of the band the activity is on wastes the twenty minutes of good propagation you walked two hours to reach. If the exchange itself is still new, write that on the back of the same card. Nobody will see it and it will save you the first three contacts.