June 25, 2016

Project: Fabricating a Anderson PowerPole to 3.4mm dc connector for the Kenwood TH-F6A

In our prior post, "Project: Hacking the Nomad 7 Solar Panel for Amateur Radio Use", we explained how to replace the stock 12Vdc 8mm male connector with the more useful Anderson PowerPole connector.

In this post, we describe how to make a pigtail cable to connect the Kenwood TH-F6A triband HT to a 12Vdc power source via an Anderson PowerPole connector.  As our starting point, we purchased a Kenwood PG-2W cable from Universal Radio.  The Kenwood PG-2W cable comes with fuses already installed.

Kenwood PG-2W
Step 1: Slide on a short length of heat shrink tubing

  • Slide on a short length of heat shrink tubing over both the tinned ends of the PG-2W cable.
  • The tubing will be used to dress the cable and provide a little strain relief.
Kenwood PG-2W with heat shrink tubing slide on


Step 2: Solder on Anderson PowerPole contacts

  • Solder (or crimp) on the Anderson PowerPole contacts onto the tinned ends of the PG-2W cable.

Kenwood PG-2W cable with Anderson PowerPole contacts soldered on

Step 3: Install the Anderson PowerPole housing

  • The positive wire is clearly tagged on the PG-2W.
  • Install the Anderson PowerPole housing such that the positive contact is inside the red side of the housing.

Step 4: Test the cable

  • Using your voltmeter, confirm that the positive contact on the 3.4mm dc connector is connected to the red Anderson PowerPole contact

Kenwood PG-2W cable - back of the package showing polarity of the 3.4mm dc connector


Voila!  That is how we fabricated our very own pigtail to connect the Goal Zero Nomad 7 solar panel to the Kenwood TH-F6A radio for the purpose of recharging the radio's battery.

Nomad 7 with Anderson PowerPoles connected
Goal Zero Nomad 7 V2 solar panel charging the Kenwood TH-F6A HT Transceiver via Anderson PowerPole cables

In the next article in this series, we will review the Goal Zero Nomad 7 V2 solar panel under challenging conditions on a backpacking adventure in the California Sierras.


Good DX and 73, NJ2X



Other related articles on NJ2X.COM


© Michael W. Maher and NJ2X.COM, 2016.

June 24, 2016

Design your own language...

"If you decide to design your own language, there are thousands of sort of amateur language designer pitfalls." -- Guido van Rossum

June 23, 2016

Field Day 2016 is here!

ARRL Field Day is the most popular on-the-air event held annually in the US and Canada. On the fourth weekend of June, more than 35,000 radio amateurs gather with their clubs, groups or simply with friends to operate from remote locations.

ARRL Field Day 2016
The objective of Field Day is to work as many stations as possible on any and all amateur bands (excluding the 60, 30, 17, and 12-meter bands) and to learn to operate in abnormal situations in less than optimal conditions. Field Day is open to all amateurs in the areas covered by the ARRL/RAC Field Organizations and countries within IARU Region 2. DX stations residing in other regions may be contacted for credit, but are not eligible to submit entries.

Field Day is always the fourth full weekend of June, beginning at 1800 UTC Saturday and running through 2059 UTC Sunday. Field Day 2016 is June 25-26.

Hope to hear you on the air.

Good DX and 73, NJ2X

June 18, 2016

Project: Hacking the Nomad 7 Solar Panel for Amateur Radio Use

In our earlier article, "Backpacking Amateur Radio Power: Alternatives" we explored various solutions to powering electronic devices (iPhone and an amateur radio HT) while backpacking.  The Goal Zero Nomad 7 solar panel met our requirements the best.

Goal Zero Nomad 7 solar panel

In this post, we explain step-by-step how we modified the Nomad 7 solar panel to make it more convenient to use in amateur radio applications.

Goal Zero has made a very handy little solar panel in the Nomad 7.  It provides power via a USB port and a 12Vdc port.  This makes it possible for us to recharge our iPhone (5V USB) and Kenwood TH-F6A (12Vdc) from the Nomad 7.  One of the great things about standards is how many of them there are. There are innumerable standards for 12v power connectors.  We prefer the Anderson PowerPole connector for our 12Vdc applications.  Unfortunately, the Nomad 7 provides 12Vdc via an 8mm connector.

Nomad 7 12Vdc via an 8mm connector

Nomad 7 5Vdc via a USB connector
In order to connector our Kenwood TH-F6A to the Nomad 7 we would need to make a pigtail.  We considered purchasing Goal Zero's 8mm female to 4.7mm male pigtail assembly for $4.99 and then cutting off the 4.7mm connector and replacing it with an Anderson PowerPole.  However, this seemed like unnecessarily complex solution that would add weight and cost.  Weight comes at a high cost for backpackers.
Goal Zero's 8mm female to 4.7mm male pigtail assembly
After talking this over with our friends at Santa Cruz Electronics we came to the conclusion that the simplest, least weight, and lowest cost approach would be to simply cut off the 8mm male connector from the Nomad 7 and solder on an Anderson PowerPole.

Replacing the 8mm male connector with an Anderson PowerPole

Step 1: Cut off the 8mm male connector
  • Leave enough wire on the Nomad 7 to comfortably solder on an Anderson PowerPole connector.
  • Leave enough wire on the 8mm connector to solder on an Anderson PowerPole later if needed.
Step 2: Strip the coaxial cable
  • Carefully strip the black plastic sheath about 1 inch.  Take care not to cut any of the copper wire.
  • Twist the copper braid into a single wire for soldering.
  • Strip the white wire to the same length as the PowerPole connector.
  • Slide on a short length of heat shrink tubing over the coaxial cable.
Step 3: Verify the positive and negative contacts
  • Place the Nomad 7 in full sun and verify the positive and negative contacts using your volt meter.
  • Our Nomad 7 produced 15.15 Vdc in full sun (open voltage).  The Kenwood TH-F6A has a specification limit of 16V.
Nomad 7 open voltage (15.15Vdc)
Step 4: Solder (or crimp) on the Anderson PowerPole contacts

  • We prefer soldering the contacts to minimize resistance and assure good contact.



Step 5: Insert the contacts into the red/black Anderson PowerPole housing
  • Be sure to install the red side on the positive connector.
  • Use your volt meter or your Anderson PowerPole Polarity Checker to confirm that the red connector has been installed on the positive contact.
Step 6: Shrink the heat shrink tubing
  • Slide the heat shrink tubing up so it is snug with the Anderson PowerPole.
  • Using a heat source, carefully shrink the tubing so it tight around the wires.
  • This dresses the construction and provides some strain relief for the connector.

Voila!  The 8mm male connector has been replaced with a much more useful Anderson PowerPole connector on the Goal Zero Nomad 7 solar panel.  We can now connect our Nomad 7 to a wide variety of devices and cables that we have fabricated using Anderson PowerPole connectors.  This seems like such an obvious design choice it makes us wonder why Goal Zero didn't choose the Anderson PowerPole instead of the 8mm connector to begin with?  Come on world, it is time to rally around the Anderson PowerPole for 12Vdc applications.

Nomad 7 with Anderson PowerPole installed

In our next post, we will build a pigtail for the Kenwood TH-F6A HT so we can recharge the radio's battery from the Nomad 7 via the Anderson PowerPole connector.


Good DX and 73, NJ2X



Other related articles on NJ2X.COM


© Michael W. Maher and NJ2X.COM, 2016.

June 17, 2016

Learning Python is a lot easier than C, C++, or Java

"Now, it's my belief that Python is a lot easier than to teach to students programming and teach them C or C++ or Java at the same time because all the details of the languages are so much harder. Other scripting languages really don't work very well there either." -- Guido van Rossum

June 11, 2016

Backpacking Amateur Radio Power: Alternatives

In our prior post (Backpacking Amateur Radio Power: Requirements) we discussed our requirements for powering our electronics in the backcountry including an HT and an iPhone.  We defined our requirements in the form of a user story with acceptance criteria.

USER STORY: As a backpacker, I need a way to use my TH-F6A radio and iPhone 6 during my backpacking trip and not run out of battery before the end of the trip so that I can have fun with the devices during the trip and have them ready for use at any time during the trip in the event of an emergency to call for help.

ACCEPTANCE CRITERIA:
  • Must allow the backpacker to use the device a little or a lot as needed.
  • Must be flexible enough to allow the backpacker to use the solution regardless of duration (our typical backpacking adventures range from from 1 night to 15 days).
  • Must not add significant weight to the pack (i.e. < 1.5 lbs / 0.68Kg).
  • Must be able to maintain power for an iPhone via the USB connection (5Vdc USB power).
  • Must be able to maintain power for a Kenwood TH-F6A via the 12Vdc connection.

In today's post, we will explore potential alternative solutions and compare them against our requirements.

Option 1: Conserve the battery

Pros
  • Practical approach
  • No cost
  • No added weight
Cons
  • Conserving the battery means using the devices sparingly over the trip.  For the iPhone it means leaving the device powered off during the hike and powering it on when needed.  Not very convenient for snapping photos while trekking.  Keeping the HT powered off is a bit more feasible.  However, we like to use the radios in our backpacking group to keep the front and rear in communication as we go to since we tend to string out a bit.
  • This approach doesn't meet our acceptance criteria of being able to use the devices as much or as little as needed during the trek.

Option 2: Pack extra batteries

Pros
Cons
  • On longer trips, one set of extra batteries may not be enough.
  • Some conservation of battery power is still required.

Option 3: Pack a portable generator: BioLite Wood Burning Campstove

Pros
  • Claims to provide portable power (USB).
Cons

Option 4: Pack a portable generator: K-TOR Pocket Socket Hand Crank Generator

Pros
  • Possible to recharge both USB and 12Vdc batteries.
  • The weight is under the limit per our acceptance criteria (1.0 lbs/0.45Kg < limit of 1.5 lbs/0.68Kg)
  • Cost is reasonable at $54.00 on Amazon.com
Cons
  • The K-TOR Pocket Socket Hand Crank Generator had mixed reviews on Amazon.com.  From the reviews is sounds like hand cranking is laborious and takes a long long time to recharge.  This is a material consideration since backpacking can be physically exhausting.  Having difficulty imaging cranking for hours after a day of backpacking 16 miles with elevation changes.
  • Requires packing the transforms for iPhone and HT.  This adds additional weight.

Option 5: Pack a solar panel: Goal Zero Nomad 7

Pros
  • Recharges USB devices.
  • Recharges 12Vdc devices.
  • Lightweight at 1.4 lbs/0.64Kg which is less than our acceptance criteria limit of 1.5 lbs/0.68Kg.
  • Easy to use and requires no physical effort to generate power.
  • Cost is reasonable at $77.31 on Amazon.com
  • Solid reviews on Amazon.com.
  • Well made and durable.
Cons
  • Need direct sunlight to recharge.  We have sunshine in abundance here in California so this isn't a material concern.

Option 5: Pack a solar panel: Goal Zero Nomad 7 is the clear winner among our alternatives.  It fits the requirements very well.  We are looking forward to putting it to the test.


In our next post in this series, "Project: Hacking the Nomad 7 Solar Panel for Amateur Radio Use" we will show step-by-step how we modified our Nomad 7 to make it more convenience to use with our Amateur Radio setup.

On a future post in the series, we will review how well the whole setup worked on a challenging backpacking backcountry adventure.


Good DX and 73, NJ2X


NJ2X.COM is now available on Kindle!

Related articles

Backpacking Amateur Radio Power: Requirements
Backpacking Amateur Radio Power: Alternatives
Project: Hacking the Nomad 7 Solar Panel for Amateur Radio Use



© Michael W. Maher and NJ2X.COM, 2016.

June 10, 2016

Light is electromagnetic waves...

"light is electromagnetic waves: the speed of electromagnetic waves experimentally agrees with the speed of light in a vacuum, and neither experiment depended on the other view." -- J. C. Maxwell 

June 4, 2016

Backpacking Amateur Radio Power: Requirements

So how do you bring an iPhone and HT on a backpacking trip and use them without running out of battery before the end of the trip?  In this post, we explore this question and the requirements in implies.

We have been doing a lot of backpacking lately in the mountains of Northern California.  Backpacking is great exercise, physically challenging, and a great way to immerse yourself in nature.  A backpacker must carry everything needed for the trek including food, water, shelter, clothing, and personal items.  Our 3-day/2-night pack weighs in around 30 lbs / 13.6 Kg.  Weight comes at a big cost to a backpacker so the objective is to minimize.

When trekking in the backcountry there is often no mobile phone coverage.  Mountain peaks sometimes provide a line of sight to a faraway cell tower which can yield one or two bars of signal.  In our experience, the valleys are barren of mobile phone signal.  We still carry our cell phones on backpacking trips because the phone provides a good camera and can also serve as a potential emergency communication device.  Being able to summon help when you need it most is invaluable.

Apple iPhone 6 makes a great pocket camera while trekking
Amateur radio VHF/UHF repeater coverage in the backcountry is more readily available than cell phone coverage in the places we have been hiking.  This makes the amateur VHF/UHF HT a valuable companion on a backpacking trip.  In an emergency situation, communication can make a tremendous difference in the outcome.

We programmed our Kenwood TH-F6A tribander radios with as many repeaters as we could covering the areas we like to travel and backpack in Northern California.  The TH-F6A transmits 5W on the 144 MHz, 220 MHz, and 440 MHz amateur bands. We also programmed them with the various simplex calling frequencies.  We bring them on every trip.  Sometimes we also use our TH-F6A with our TinyTrak4 TNC and GPS for APRS tracking.  The TH-F6A has a wide-band receiver which allows us to listen to broadcast radio in camp (AM/FM).

Kenwood TH-F6A Triband VHF/UHF HT is perfect for backpacking
The challenge with bringing electronic devices on a backpacking trip is getting utility from them without running out of power before the trip ends.  We don't simply want to throw the devices into our packs powered off during the trip in order to save the battery.  So what are the requirements for the solution?  We defined our requirements in the form of a user story with acceptance criteria:

USER STORY: As a backpacker, I need a way to use my TH-F6A radio and iPhone 6 during my backpacking trip and not run out of battery before the end of the trip so that I can have fun with the devices during the trip and have them ready for use at any time during the trip in the event of an emergency to call for help.

ACCEPTANCE CRITERIA:

  • Must allow the backpacker to use the device a little or a lot as needed.
  • Must be flexible enough to allow the backpacker to use the solution regardless of duration (our typical backpacking adventures range from from 1 night to 15 days).
  • Must not add significant weight to the pack (< 1.5 lbs/0.68Kg).
  • Must be able to maintain power for an iPhone via the USB connection (5Vdc USB power).
  • Must be able to maintain power for a Kenwood TH-F6A via the 12Vdc connection.

Now that we understand our requirements, in the next article, we will explore potential solutions.


Good DX and 73, NJ2X


© Michael W. Maher and NJ2X.COM, 2016.

June 3, 2016

I turned off the light...

I'm so fast that last night I turned off the light switch in my hotel room and was in bed before the room was dark. -- Muhammad Ali

May 27, 2016

Shining substances...

Are not rays of light very small bodies emitted from shining substances? -- Isaac Newton