Lower Power, Less Gear!

Hello Operators.

You all know I spend an awful lot of time on the radio. I’m always trying to find an optimal configuration for my radio equipment, at home and out in the field. At home is pretty easy. Out in the field especially on foot, we need to come up with more clever ways for more efficient Communications.

The first time I went to Lapland man-portable, on foot carrying my entire station is the video you see above. I took the Yaesu ft-891, a 120 watt PowerFilm panel, and 10ah LiFePO4 pack to power it all. I have no regrets about that configuration because its sole purpose was radio communications. In fact, that the entire trip was about Man portable, off grid Communications.

I did the same for winter Field Day 2020, albeit in horrific temperatures. I’m definitely not saying a qro field station is always going to be the right station to deploy. It certainly is one when Communications is our primary reason for being out in the field.

What about when being off-grid is the purpose!? Travelling man portable, just taking amateur radio along!? We certainly wouldn’t carry a 100 watt radio on a thru-hike. What about when the main point of the trip is “the travel”!? In that scenario, we need to downsize the kit, then come up with more efficient ways to communicate. We also need to run less power. I know those things sound like they work against one another, but they don’t have to. That’s why we turn to modes like JS8Call and FT8!

If we think about the three low power or QRP radios most often talked about on the channel,

  • Icom IC-705
  • Yaesu FT-818
  • XIEGU G90

… we begin to see something they each have in common. They each draw less than 5A on full transmit. When we’re not operating qro, we can look at less forgiving portable power options, because we’re simply drawing less power. Still we have to answer the question of how we’re going to communicate with less power. Once again I’ll direct you to JS8Call. JS8 is not the only mode. CW is also a very energy efficient mode. It’s only real drawback is it can’t be decoded under the noise floor. JS8Call, CW, FT8 are all very effective at 10 watts, provided you have an optimized antenna configuration. Remember we’re defining effective Communications in this way; Effective communications is defined as “reliable communications directed to a specific station, at will”. We’re not talking about winning some DX contest. We’re not talking about reaching a random station with SSB or other wide bandwidth mode. For example, we could be talking about sending and receiving email with winlink/pskmail. We could be using JS8 to send a position report or email, over HF, to the aprs-is.

My point is there are low-power Communications options available, provided you’re not trying to work a DX contest expecting to win. In the next image you can see my station being powered by a small portable storage device from PowerFilm.

In the above example, I’m using this energy storage system to power the raspberry pi, and the Xiegu G90. Output power 15 watts, with clean signal and good reports. I’ve got complete Communications throughout Scandinavia, Europe and North Africa, albeit slow communications.

The Xiegu G90 was pushing RF into a portable Delta Loop I’m currently testing from chameleon antenna.

So we’re running a 20 watt radio, powering the Raspberry Pi, and using a “weird” antenna. It’s all being done with this PowerFilm Solar Lightsaver Max.

PowerFilm Lightsaver Max

Enter the PowerFilm Lightsaver Max. The lightsaver Max has an 18 amp hour lithium ion internal battery. It also has what we believe is a 10 watt solar panel for recharging the internal battery storage, out in the field. The Lightsaver Max can quietly power a 12v load at 5A.

It has two 2.5 amp USB outputs, and a 12 volt 5 amp output. It can be charged via USB-C, 12 volts DC, and its own integrated solar panel. It can also be daisy-chained with other solar panels. I suspect I’ll be using this with my 20 watt FM16-1200, since it weighs nothing, and takes up no space.

Hoping to start field testing qrp or at least low-power, after I publish the next video.

73 Julian oh8stn

PowerFilm Lightsaver Max Amazon US , Powerfilmsolar.com

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2 Comments

  1. Watched your YouTube video re construction of LiFePO4 supply. Very nice. Will be an undertaking but worth the effort for all the reasons you pointed out. Curious…where is Yeti and OMMO manufactured. not easy to find that out as they tend to hide that information. Do you Know?

    • Unfortunately I don’t know. They hide that information because they don’t want us building our own. Interesting question though.

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