*PRODUCT REVIEW* EF1000iS Portable Power

DXpedition, field and portable radio comms enthusiasts are always on the hunt for a good engine that converts mechanical energy into electrical energy by electromagnetic induction (i.e. a generator); one which is not only capable of handling the requirements of an amateur rig and its harmonizing DX-cessories (e.g. a power supply, amplifier, etc.), but one which is ultra-dependable also, super quiet and fuel-friendly.


On this note, the EF1000iS is one of Yamaha’s new gennies and one which sparked my attention on a recent visit to the local hardware store. 

The first thing that grabbed my interest was the funky blue appearance which reminded me of the colours used on the DA-RC website funnily enough; but after a quick read of the product spec sheet the attractive intrinsic qualities of the unit soon came to the fore and a voice in my head started screaming, “BUY ME!” BUY ME NOW, DAZ!”

Following a brief finance check with the YL, and a colourful exchange of words on my excessive hobby expenses, a tad over $1000 was handed over to the salesperson and I hurried out of the hardware store to the 4WD with my new toy under arm.

More often than not you’d expect to have to wheel such an item out of the store in a shopping trolley, or strung between 2 or 3 sets of rounded biceps, but this one was as heavy as a case of beer and, at 450(L) x 240(W) x 380(H) mm, not much bigger either!

No sooner had I returned to my home QTH than I had a mock portable station erected in the backyard with the Yamaha genny tanked up alongside purring like a kitten drunk on titty milk; complete with a wound up Alsatian and Labrador and three small kids running wild in the same vicinity. 


The things we DXers have to contend with…pffff!

My Findings

The Yamaha EF1000iS generator confidently ran my station for 8 hours without refueling until I had grown weary of working stations in the Americas and disappeared inside to watch the footy with a few mates. 

Then the 4-stroke OHV 50cc engine was switched off!

According to the product spec sheet, the Yamaha EF1000iS will actually run continuously for up to 12 hours without refueling (at 1/4 load with “Economy Control” function on) due to its double coil system so theoretically I still had another 4 hours of ops left before the funnel and gerry can would have to be heaved out of the shed again. 

Not bad for just 2.5 liters of fuel and far more efficient than some of the other fuel-thirsty gennies on the market!

In additional to being economical, my 8 hour testing period also confirmed that the Noise Block Acoustically designed sound reduction system with its molded casing, noise-absorbing glass wool construction and a newly designed muffler, produced what I would describe as excellent noise reduction. 

In contrast, past experiences with gennies during IOTA DXpedition and field work have not been what I would call pleasant on the ears of fellow campers or my own so this was a welcome change indeed!

Another one of my fave features was the centralized control panel which made it easy to access controls. 

These were basic also — exactly the way I like it !

My Conclusion

In my eyes, the Yamaha EF1000iS inverter generator ticks all the boxes for DXpedition, field and portable radio comms use and is the ultimate in lightweight portable electricity.

At 12.7 kg and with its convenient carry handle, it can be easily carried across rugged terrain to access remote DXstinations such as islands or portable locations such as mountain summits. 

The small weight also helps to keep costs down with air travel too where charges for access baggage fees can cause a real dent in the DXpeditioner’s hip pocket.

On another point, the Yamaha EF1000iS’s clever inverter system and Pulse Width Modulation (PWM) means it delivers clean power which I’m sure would confidently power computers, solid-state appliances with built-in computer functions and other microcomputer-controlled power tools as well as any ham station. 

This basically means that it can be used to run other apps such as laptops with computerized logging programs during the DX adventure also which cancels out the need for a second and larger genny.

Given it is also tremendously quiet and easily handles the power requirements of a ham station, I have no hesitation in recommending the Yamaha EF1000iS inverter generator to other DXpedition, field or portable radio enthusiasts who require a generator as a mobile power source.

For more specs on this product, please read below…



  • Engine Type: OHV MZ50 air cooled engine
  • Displacement: 50 cc
  • Max. Output): 1.6(2.2)/4000 kW
  • Starter System: Recoil
  • Fuel Tank Capacity: 3 L
  • Operating Hours: 12 (No Load) Hr
  • Noise Level: 47/57 dba @ 7m


  • Length: 450 mm
  • Width: 240 mm
  • Height: 380 mm
  • Wet Weight: 12.7 kg with 3 litres of fuel


  • Generator Type: Inverter
  • Rated Voltage: 230 V
  • Frequency: 50 Hz
  • Rated Output: 0.9 kVA
  • Max. Output: 1.0 kVA
  • DC Output: 12V/8A

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