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Topics - STN

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General Discussion / Yaesu FT-891
« on: March 13, 2018, 01:25:53 PM »
Hello Operators
Topic of the day is the Yaesu FT-891. Many field radio operators have turned away from the Yaesu FT-891, because of the specs regarding current draw on RX, published on the Yaesu website. Since I have owned the Yaesu FT-857, and 897 in past years, the current specs for the 891, seemed somewhat off! In fact, I wondered if Yaesu simply published "worst case" numbers on the site, without bothering to publish a range of numbers which would make more sense to potential buyers. So, in this video we'll be measuring the current draw of the Yaesu FT-891 at RX, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 Watts.

I've had many requests on the channel for such a video. Operators would like to compare current consumption to other popular rigs like the Yaesu FT-857D, Icom 7200, Icom 7300, as well as understanding how hungry this radio is when deployed in the field. Operators would also like to know why someone would choose a rig with a 1A RX current draw. Spoiler Alert! The truth is, we need to find the balance between QRP/Ultralight amateur radio, and QRO/when your life depends on getting the message out.

The truth is, the FT-891 weighs in slightly more than the FT-817ND with internal batteries. The LiFePO4 batteries I use can work with my 817 or 891. The trick to deploying a rig having such a current draw, is deploying with a lightweight solar panel and charge controller. I know Gil and I disagree on this topic but cheap is never going to be lightweight, and eventually, when your life depends on it, we all wish we would have purchased a thin-film flexible solar panel. No real survival minded person seriously thinks the ebay special from China with a built-in voltage regulator will do the job, but it is cheap! So I deploy both the 817 with a 20w thin film panel, and the 891 with a 120w thin film panel. The 120w panel runs my entire field station btw.

The following link is to my Yaesu FT-891 Current draw test.

This link is a playlist (which completely contradicts much of the gospel found here) on off grid solar and battery power for field communications.
Portable off grid power for amateur radio. amateur radio
Don't let the titles fool you. Everything I do is about extended field communications in a grid down scenario- The vanilla titles and tags help spread the word to a wider audience.

I do encourage everyone to get off the couch, get out in the field, and test their gear to near failure. Anybody can make videos, blogs or write forum posts. At the end of the day, it is field experience which will save your life.

Julian oh8stn

General Discussion / Portable Solar Powered GoKit for Ham Radio
« on: August 02, 2017, 12:56:13 AM »
Hello Operators.
Over the past few weeks I've published several articles entitled "Man Portable Off-grid Power for Amateur Radio", on This video is the result of that research & field testing. In this video, I'll breakdown each module & component of my Portable Solar Powered GoKit for Ham Radio. Later on I'll do individual build/review videos for each component.
The  kit follows a "Lego block" approach, and is designed to be modular. The kit is based on three unique  modules:
- Power & DC distribution
- Radio & Computing
- Antennas & Support

The entire kit weighs between 7-10 kg depending on the options chosen (including 1L water and rucksack) .
You can find links to the original blog posts, research, field testing, and the usual plethora of full HD images, in the video description, or by visiting the companion blog post at
de oh8stn

Tactical Corner / All Weather Shelter for Field Communications
« on: August 02, 2017, 12:34:56 AM »
Hello Operators.
Today we're talking about field stations, or actually the shelters we use when operating man portable or as portable field stations. Last April 2017 I participated in the radar challenge. I suffered some pretty awful conditions with snow, freezing rain, frostbite. After that, I began to realized it was time to reconcile my all-weather operating conditions.
This article discusses an all-weather shelter for amateur field communications. It shows you what I'm using now, and what I'm upgrading to in the near future.
If you've also been thinking about shelters or already have a solution, please tell me about it in the comments.
de oh8stn

General Discussion / Digital "Field Day" 2017 New article up.
« on: June 27, 2017, 03:35:54 AM »
Hello Operators
 I just posted a new article on Field Day 2017, which may be interesting to some of you and this forum.
 Now unlike ARRL field day in North America, I approached field day from Comms preparedness and digital Comms perspectives. My goal was to use a very specific digital mode or digital system (FSQ), to establish effective low-power communications with two stations (Norway & Netherlands ) using an off-grid, solar powered, qrp field station.
I also want to reach out to thank PE4BAS & LB9YH, for unwittingly helping me to prove or disprove my station capabilities, during what we called "Digital Field Day".

Here’s a breakdown of the goals

- Testing FSQ for Effective low-power data Communications in the field.
- Testing the PowerFilm F15-1200.
- Testing the Genasun GV-5 with a protected 4s LiFePO4 pack.
- Testing the effectiveness of the Chameleon P-LOOP 2.0 with the Booster kit.

Enjoy the read.
de oh8stn

Batteries & Solar / Man Portable Off-Grid Power for Amateur Radio
« on: June 26, 2017, 03:20:11 AM »
Hello Operators.
I've been watching this thread for some time and thought I would share my own Journey and evolution with portable power for amateur radio communications. Not too long ago I was using in nickel metal hydride batteries, as the primary power source for my radio communications. Although I enjoyed using the Enelope nickel metal hydride batteries, their energy density is nothing compared to lithium ion or lithium iron phosphate. The price was right however.
But after walking 40 kilometers on an off-grid emergency deployment exercise, I realize I needed to increase the storage capacity of whatever energy storage solution I decided to carry with me. That left me with two options.
  • a larger or parallel nickel metal hydride pack with increased weight
  • finding a battery chemistry with increased energy density for the same weight
I did go on to use the nickel metal hydride packs with it pwm charge controller for quite some time. Now I've repurpose that charge controller, as a standby power go box with a 9 amp slab, wall mounted inside a small Pelican case.

The first upgrade
That's when I built the QRP battery pack . This first pack was a lithium ion battery pack with 3.4Ah capacity. I used four 18650 batteries in series and a battery balance and protection board, to manage low voltage, overcharge, Short Circuit, and balance the cells.

I could connect the qrp battery pack to any of my solar panels, using the combination of battery pack and solar panel for sustained Communications in the field. Although the complexity of the build might seem daunting to many operators, the result is a stable lithium ion energy storage solution, with simultaneous charge and discharge capabilities. Fortunately I needed to use a DC/DC CC/CV power supply with the qrp battery pack. That was okay until later on when I found a better solution.

The second upgrade
The qrp battery pack was the first step in ultra-portable off-grid power for amateur radio. Unfortunately that pack could be looked at as nothing more than a rapid deployment, high speed low drag storage solution. Up until that point my solar panels we're still critically underpowered or overweight. I had the 10 watt solar briefcase from Harbor Freight. This was a total waste of money. Then I settled on two Goal Zero Nomad 7. The Goal Zero panels held me over for a while. They were not too heavy, they had both 12 volt and USB output and they could be chained together easily. Unfortunately their pieces of crap and the designer should be burned alive at the stake. The point of failure on The Nomad series of solar panels is the little box which holds all of the electronics. The cable breakout box works itself loose causing a short circuit in the worst-case or no connection at all. And despite their best marketing these is neither waterproof or water-resistant in any way. This led me to the PowerFilm F15-1200 20w  flexible thin-film solar panel. By itself it weighs less than one of the Nomads, but brings in 1.2A of energy collection with a big reduction in weight. It can also be damaged without becoming completely useless. The only downside is the price.

Upgrade number three
With the acquisition of a good panel I also needed to invest in a good solar charge controller. I'm pretty sure most of you will find this acquisition excessive, but it's my opinion that we spend too much money on trying to hack a solution together instead of buying the right thing the first time just once. That brought me to the Genasun GV-5 solar charge controller for lithium iron phosphate batteries The Genasun is a 5 amp solar charge controller which is completely RF noise free! One can directly connect a lithium iron phosphate battery pack (with bms board), a solar panel,  and a qrp radio on the load port. The BMS board in my qrp battery pack was compatible with both lithium ion and lithium iron phosphate depending on the input voltage. So to use my little qrp battery pack I simply had to swap out the lithium ion batteries for lithium iron phosphate 18650 cells. That was the Prototype!

Digital Field Day 2017
Last weekend (June 34 2017) at field day I used this combination of energy storage, solar collection, and Battery management to power my digital Field Station for 4 hours. I was using a digital mode called FSQ, to interact with two operators. The first operator was in the south of Norway, while the second operator was in Netherlands. Most of you already know I meant 65° North in Finland. We did text chat, exchanged images, interacted with the automated functions of FSQ, ... as a test for establishing reliable low-power digital Communications from the field. The test also confirmed that the combination of gear provided a lightweight Ultra portable off-grid power solution for field communications.
Here are a few things I learned.
  • Hacking cheap chinese gear and learning by doing so are fun, but at some point we need to start engineering reliable solutions for off-grid comms
  • the investment in quality gear will often solve more problems then immediately apparent. For example the two Goal Zero panels were cheaper than the Powerfilm, but the PowerFilm saved me weight, increased solar collection, and reduced the complexity of my system
  • integrating the solar charge controller and lithium iron phosphate battery pack gave me simultaneous charge and discharge capabilities. That means no more fumbling around with AA batteries, swapping out battery packs, ...

The next step
So now that I know that everything works as one integrated system, it's time to increase the storage capacity of my system. The 3.4Ah pack does a great job in the summer months at 65 degrees north, because we have 24 hours of sunlight. For winter operations in the field I'm going to double up on the solar panels (adding a second PowerFilm F15-1200), and in the coming weeks start building a 10Ah version lithium iron phosphate protected battery pack. This offsets the fact that we have almost no daylight during the winter months.

Finally a word of caution. I once review day cheap Chinese solar panel on my channel. It was called Choetech 19w folding panel. I finally realized the gimmick with these cheap Chinese panels. They all have a USB output, and they probably are accurate in regards to the potential wattage they can collect. However they deceive us when saying the USB output has two amp rating or 2.5 amp rating, because the solar panel itself could never generate that amount of amperage, without having several of those panels in parallel. They're not lying they're just not telling the whole truth. If you're into preparedness Communications, it's time to start building or buying your own quality gear.

de oh8stn

Digital Modes / Ultra-Portable Amateur Digital
« on: October 07, 2016, 04:44:37 PM »
Hello guys.
I'm often asked about ultra-portable amateur digital comms. So I thought right now would be an excellent time to kick off an ultra portable digital comms series. In this article we discuss three different variants for Ultra portable amateur digital communications. We go through the benefits and weaknesses of each system as well as briefly covering system capabilities.

You can read the full article here.


Hi operators.
Just sharing an interesting new project that I'm working on.
I believe my project solves many of the problems that others have had with Lithium-ion LiFePO4 batteries in the past. By introducing a balancing and protection circuit BMS, we can simultaneously charge or discharge the pack without worry of cell damage from under voltage, overcurrent, ...

The QRP UltraPack External Battery Pack project is an open source project designed to provide radio operators with a low-cost, scalable, and customisable external battery pack solution for modern QRP rigs like the Yaesu FT-817 and Elecraft KX2. It is very much like a QRP Ranger, but smaller, and more configurable. The QRP UltraPack can be built at home as a 4S1P 3.4A (50watt hour), 4S2P 6.8A (100 Watt hour), or 4S3P 10.2A (150 Watt hour) power pack using 18650 cells, by anyone with basic ham radio or ohms law skills.

I would very much enjoy feedback on my project, but I ask that you study the attached image, or read the project page before commenting.

SurvivalTech Nord

Antennas / -Alpha EZ Military vs Chameleon MPAS
« on: February 16, 2016, 06:01:37 AM »
Hello radio operators
I just published the first video in the 'Alpha EZ Military vs Chameleon MPAS' series.
This first video 'Alpha EZ Military Gold First Look'. It will be followed up by 'Close up look at the Chameleon MPAS'.
After that, I'll publish the side by side comparison, then follow up with performance tests.

You can watch the first video here

You're all welcome to follow along, comment and of course politely debate. My job in all this is to provide objective information!

73 de STN

Hello guys.
I just posted a new video  where I setup and tested the WolphiLink audio interface, with FLDigi, on a laptop running AntiX-15 Linux. Normally we would use this audio interface on an android smartphone or tablet. I thought since I have a couple of them and they're so inexpensive anyway, it wouldn't hurt to make a cable or buy a splitter to see if this would work out well on the Linux laptop.

Another reason I'm using Linux it's because I'm sick and tired of Windows, and all the problems associated with it. Normally for ham radio digital modes I'm using Android and that works really well, but fldigi is not mature enough on Android yet. That's why I switched over to AntiX Linux for my emergency digital communications setup.

If anyone's interested the laptop is an Asus Eee PC 1000 H.

I'll be doing a lot more with fldigi on Linux, using thecFT,-817ND,  WolphiLimk, and my faithful magloop.
Here's a link to the video


Digital Modes / Digital Modes with Android and FT-817ND\YouKits TJ2B
« on: January 10, 2016, 04:58:01 AM »
There's lots of talk about digital modes in this forum but I thought to introduce the idea of using an Android device as the computer for PSK31/63, SSTX, RTTY,  WSPR,  HFAPRS

My current setup
- Yaesu FT-817ND or YouKits TJ2B
- Google Nexus 9 or Samsung Galaxy S4 i9506
- WolphiLink radio interface
- Chameleon F-Loop or Chameleon MPAS

- DroidPSK
- DroidRTTY
- DroidSSTV
- WSPR Beacon

The WolphiLink is powered through the TRRS port on the smartphone or tablet. It handles audio levels and PTT. I enjoy the WolphiLink since it requires no external power source or drivers.

The benefit of using Android over a laptop is power and efficiency. It's far easier to power an Android device for longer off grid then it is a hungry Intel powered laptop. The downside is there aren't that many apps for amateur radio or emergency communications on Android yet but they're coming. The most recent addition being fldigi for Android.

Here is an example of me doing PSK31 with my FT-817 and Samsung Galaxy Tab 10.1 (its an old video).

If this topic is of interest to anyone, I'll start making a few new videos of data mode ops using Android devices and the Wolphilink interface as an alternative to Windows based solutions.

73 &Good DX

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