Fox Box - Can it be this easy?

For quite some time both Arlene and I have looked at article after article on something called "fox hunting" also known as direction finding.  This is an amateur radio "sport" of locating a hidden transmitter by using various methods such as a radio with a handheld Yagi antenna.

We have some of basics we need to go searching but no one was doing fox hunting in our area.  At least we had never heard of anyone doing it.  Therefore, we decided to do a hunt for ourselves. But wait there was one thing, one very important thing, missing.

THE FOX!

I decided to look into building a fox box, which is typically a weather proof box which contains a low powered transmitter and a controller of some sort that fed the transmitter some information to, well, transmit.   I looked through the internet resources and found some great little gadgets that work on one or maybe two frequencies at very low power usually in the milliwatts range.  This was fine, but what if you wanted to use a little more power and be able to try fox hunting on 2 meters or 70 centimeters and vary the frequency from hunt to hunt let's say.  I really found nothing.

This of course this led me to building one for myself.  I sat and thought about it, assembling a parts list and drawing possible designs and then suddenly it hit me.  What do you really need for a fox box?
First you need a transmitter.  Well, as you probably already know there are several handheld amateur radios that are so cheap, everyone considers them as disposal radios.  Could I use one of these?  Let's say an old Wouxun or Baofeng or one of the other no name manufacturers.  Seemed reasonable.

Now the hard part was the controller.  What does a controller do?  On a periodic basis it sends information to the transmitter so that people can hear it, to basically find it.  I looked at Raspberry Pi, Audrino and specialized units, but being someone who is frugal to the point of cheapness, these were all too expensive.

Again I pondered what did I have in the house already that would do the same thing.  It had to give audio to the handheld's microphone port.  That port on a Wouxun is an 3.5 mm jack.   Then the light went on.  I have an MP3 player, which I brought for $30 AND a Wouxun radio.  Is that all I needed?
Could it be that easy?

I recorded a 3 minute MP3 audio file which has in it the following:
"Here is the K7RFH fox box operating on a frequency of 145.65 FM, K7RFH fox box"
The 3 minutes included a period of silence to make up the total of 3 minutes including the message. Now, this can be any amount of time, so I made several version of varying times.  The shortest being 30 seconds and the longest my original 3 minute version.

I then setup the Wouxun to accept VOX input.  Using a  3.5mm to 3.5mm plug cable, I plugged one end into the MP3 player and the other into the Wouxun microphone input jack.  Set  the VOX level to 3.  Turned on the radio.  Turned on the MP3 in "repeat a single track" mode. Now, every 3 minutes the radio announces its call sign and a little more.

Since I have never done this before, I am not quite sure if this is a good way to do it.  I think I need to stay in control of the radio, so that means I will need to know were it is at all times and be able to get to it quickly in case something goes awry.  This is because the fox box operates in the ham band and runs 2 to 5 watts.  Although given the antenna, it may be quite a bit less power.  The control part  should not be a problem. The high power may be an issue for the hunters.  With the higher power, it means that the signal will be stronger and may ricochet giving false directions.

Finally, I needed a weather proof case.  Fortunately, I had purchased an ammo can set at Sam's Club. The larger can was used to make a radio in a box. You can see that one here.  However, the smaller one was just one of those sizes that might have worked to carry a small 7 AH battery and maybe some extra parts.   However, now I have a handheld which is 124.5mm × 61.49mm × 33.88mm plus an MP3 player which is 0.6 x 1.6 x 2.6 inches.  These together would be nothing inside the ammo can.  So, perfect!

Laying the ammo can on its side, this was clearly a good spot for an NMO antenna mount.  I had one just laying around.  Drilled a 3/4 inch hole and poof, the antenna mount was ready.

Final issue is power.  The Wouxun should be able to transmit for about 6 hours and the MP3 player is good for about 18 hours, all on their own power.  If  I wanted to make sure  I had more battery power I could put a 7AH battery or a USB power brick in the case.  Both would fit.  So now with just a few more parts the entire box could probably run for 24 or more hours.   Of course, fox hunts are usually over in just a few hours.  Everyone would get too bored if it took much longer than that.  So each devices' on-board power will be just fine to start out.

Personally, I was very surprised how easy it was to create this very simple fox.  Total cost for parts I did not already have is... well nothing.  You may not have all the share parts that I keep around so here is the estimated breakdown of costs:

• Handheld radio = $30
• MP3 Player = $30
• Ammo can = $10 (part of set)
• NMO mount and connectors = $12
• Antenna = $12
• Miscellaneous wiring = $2
• Total is about $96.  
• You can probably do better than this on e-Bay!

Now on to building some hunting devices!

Days have passed and I now have two options for a fox box.  In addition to the original MP3 version, I decide to spend some money and buy a unit that could be controlled via radio signals.  The new option came from Byonics.com

The first option as described above is the MP3 player/Handheld transceiver. This provides voice transmissions and timing is controlled by how long the voice portion plus a period of silence is recorded.  That is it.  Nothing special. No control of unit.

The second option replaces the MP3 player with Byonics PicCon unit.  The PicCon unit costs $42 as a kit or assembled for $66.  What the PicCon provides is pretty amazing.  When connected to a transceiver via the microphone in and speaker out, the PicCon can be remotely programmed and controlled.  Connecting the PicCon and radio required either building or buying a compatible cable.  I selected to buy the cable from Byonics for $19.  I figured the ease of assembling the fox box accounted for some time well spent.  The PicCon's capabilities and user manual can be found at http://www.byonics.com/piccon/

 Below are photos of the two configurations.

This is what the Fox Box looks like from the outside.  Photo 1 is the "carry" look.  



Photo 2 shows the NMO cap removed.  






Photo 3 shows the 2 meter antenna attached.

This is the MP3 version. Note the headphone jack on the MP3 player is connected directly to the microphone input on the HT.  The HT is setup with VOX control on the microphone.

This is the PicCon version with 12V battery pack to power the PicCon "Hidden Transmiter Controller". The PicCon is controlled by DTMF tones from the HT or via tones heard over the air.

Comcast strikes again or why I hate Comcast!

Got a call from Comcast promotions.

Stop there I should have. But no,

I listened to the offer and at the end of the call said I was not interested. Hung up. At that moment our internet went down. Coincidence?

Called them back and they denied that they had the ability to "turn off" our internet. Since I went through this same scenario several years ago, I knew that they did. I have never ever had a good experience with Comcast.

Stop there I should have. But no.

Called Comcast customer service. Well, you can guess how that went. Ended with me saying, that I could not waste anymore time with them.

Final result, the network did eventually come back, obviously.

If there was a high speed alternative to Comcast in our area, I would be off Comcast in a heartbeat.

In my opinion, Comcast sucks!

P.S. Hopefully, it is just our case because a lot of people still subscribe to Comcast and they would all be very angry people if they went through the crap that we have experienced with Comcast.

20151225 sUAS First Flight

Like just about everyone else, we too got a quad copter for Christmas gift. Thanks Jen!

This is Arlene's first flight learning how to fly it.  We are both already registered with the FAA sUAS database.  Although this one really didn't need that since it is well under the .55 pound weight threshold.  But we figure you can't beat the free registration for the first 3 years.



Go for it ace!

Started DXing on 2015-01-01, here are some QSL cards for K7RFH

e-QSL Cards for K7RFH

Search and Rescue Radio in a box

Arlene is a member of the Incident Support Team (IST) for King County Search and Rescue (KCSAR).  She recently decided to purchase the standard KCSAR radio, which is a Kenwood TK-780.  Initially, she didn't want it permanently installed in her Toyota pickup, so I suggested putting it in a small box.  Apparently, I must really like building radio-in-a-box setups because below you will find photos of  the end result.

Before that here are some of the details that went into making the project.  Total build time approximately 60 minutes, except for the travel time to Harbor Freight where I purchase a small "aluminum" case on sale for just over $11 (always use your coupons!).  It has only an aluminum frame.  The black portions between the frame members are made of a fiberboard that comes very close to a highly compressed cardboard.  Yet, they advertise this as an aluminum case.

Case measures 7 1/2 by 11 1/2 by 4 1/2 outside dimensions.  Inside dimensions are 6 3/4 by 11 by 4 1/8.
Granted this isn't very big, but Arlene's request was to make it small enough to easily carry and store anywhere in her pickup. I believe that was accomplished, because it is in fact "Arlene Approved".

The weight needed to be light and to that end the entire setup weighs a mere 5 pounds, 6.5 ounces.  Optionally, there is enough room to include a direct connected 12 volt 7 AH battery, however this would nearly double the weight since the battery weighs  5 pounds, 4.4 ounces.  Although Arlene tested the "carry" of this option and said this would not be a problem for her, if needed.

A small aluminum bracket was used to raise the radio enough so it could be angled to make the display easily readable and the microphone jack is above the box edge.  The bracket was from an old tower PC, it was a 5 1/4 inch drive bay filler.  This came out of my projects junk box, so it was free.  The bracket is pop-riveted to the bottom of the case.  The radio included a mobile bracket, which was then screwed to the aluminum bracket.  That was the entire construction process.

Radio is attached to the mobile bracket, power and chassis ground cables were routed so can be used with the power accessory plug and chassis ground connection installed in the pickup, respectively.

The setup for in pickup operation is as follows:

1. Open box, drag out the antenna pigtail, Anderson Powerpole connectors for power and chassis ground
2. Attach antenna, power and ground wires already in pickup to the matching box items
3. Turn on pickup and then radio
4. Listen and talk!

The photos below can be enlarged with a click.  Purchased items were Harbor Freight case, KCSAR radio, Anderson Power Poles and  battery (from earlier project).  Recycled part was the aluminum bracket.

View from handle side, standing on hinged side.

View with box on base.

Opened box with basic setup.

Cables shown are VHF antenna pigtail, fused power lead,
chassis ground and microphone.

Optional battery is inserted to the right of the radio.

Packed for case closure, with optional battery.

Power your laptop from your radio Go-Box battery!

First off, I am not any kind of electrical expert.  However, that never stopped me from experimenting.
Granted fuses fear me when I come near, but if you know someone who is skilled with electrical knowledge then you have every reason to give your ideas a path to reality.

Well, Jim, K7JGM gave me a new idea for my Packet Go-Box.  He mentioned that his Go-Box contained a Powerpole outlet to power his laptop computer.  This means that it is possible to tap the 12 volt power supply for the radio to power a laptop.  You just need a way to step up the 12V to something like 18 to 19 volts.  The specific output voltage depends on which laptop you own.  In my case the Toshiba  laptop I have dedicated to my packet station needs 19 volts.  I obtained this information from the power brick included with the laptop.  The power brick tag says output is 19 volts and 3.95 amps.  Being the trusting person that I am, I measured the voltage coming out of the brick and it read 19.6 volts.  Close enough.

The voltage step up is done by using a DROK DC Converter Voltage Regulator 8-32V to 9-46V 12/24V 150W Boost Step Up Power Supply Module which is available from amazon.com  The regulator can be adjusted easily to match your output needs.  However, be sure the output range of the regulator is appropriate for your particular laptop.

For your Go-Box, you simply tap the 12 volts and install a Powerpole outlet somewhere accessible for you laptop.  In my case, I already had a Go-Box built with 12 volt Powerpole outlet so, I decided to make an external 19V converter.  Below you should see the convertor installed in a plastic "case" with  Powerpole connectors on both input and output.

The case for the converter is a $1 plastic box from the stationary section at our local Fred Meyer. Several holes were cut in the case to allow the Powerpole wires to enter the box and to allow the cooling fins to be exposed.

Finally 5 small holes were drilled to allow access to the screws which secure the wires AND the voltage adjust screw.

Lastly, the scary part is cutting the wire on the power brick that goes to the laptop. This way you can install Powerpole connectors on each side of your cut, as shown here.  This allows you to connect the laptop's power connector to either its original power brick OR the new converter you just assembled.   That's it, enjoy!

UPDATE (2014-05-10) :

So, you have a Dell laptop and it has a "smart" power brick.  Well guess what!  Instead of having the typical 2 connector power port, it has a 3 connector setup.  That center pin is a way for your laptop to tell if the power brick is the correct one. Unfortunately, if it thinks the charger isn't the correct one, then it allows it to power the laptop but not charge the battery, even if it has the correct voltage.  Some folks in the various forums have suggested to just send the 19 volts down the center connector as well, but don't do it.  That connector expects no more than 4 volts so more then that may kill the "smart" chip.  See http://kakopa.com/Dell_PS/index.html for some background.

However, all that said it is possible to use the converter with a Dell.  Since I have a great appreciation for Anderson Powerpoles that is what I used to make sure everything connects correctly.  The images show how to wire the connectors to use all three wires when the power brick is connected and how the converter connects.  Note that the Center Pin is labeled for photo reference, since the Powerpoles are used there is only one way to actually connect everything.  Red goes to the + 19 V connector which is the inner shield. One black goes to the ground outer shield and the other black (sorry I didn't have another color, which they do make) goes to the center pin.

Everything works as usual when connected to the power brick.  However, when the converter is connected the laptop whines about it being the wrong charger and it won't allow battery charging. How rude!  If you leave this situation alone then the battery slowly discharges.  You probably won't notice it because the converter is powering the laptop.  The issue occurs when you disconnect the converter and expect the battery to power the laptop.  If the battery has fully discharged, well you guessed it, the laptop goes black when converter is unplugged.

An extremely simple solution is to remove the battery after the converter is plugged in.  The only change with the battery removed is that the converter's fins warm up just a bit more than with the battery inserted.

If someone knows a way to fool the laptop into believing it has the correct power brick, please let me know.

RMS Express installation improved by using AGW Express Interface-Solution Set

Quite some time back I decided to use my amateur radio to send and receive packet messages, so I carefully researched what I needed, which included:
Hardware - 2 meter capable amateur radio; antenna; computer and interface between computer and radio AND of course "some" software.

Back then it was, to say the least, a challenge to get find everything you needed then get it all  installed, configured and running correctly.

Not so now!

Now, you can go over W2YG's Software web site and download AGW Express Interface - Solution Set which will assist you in installing and configuring all the software parts needed to send and receive packet messages.  BTW, it also covers HF messages as well, but I won't touch on that  here.

Here is my list of parts:

• Yaesu FT-897D
• SignaLink with appropriate cabling and jumpers
• Old Dell laptop (running Windows 7)

Procedure for setup:

1. I will assume that you followed the directions to install the SignaLink. If not, finish those steps using the Tigertronics web site instructions.
2. You now have the USB cable coming from the SignaLink and the SignaLink's other cable plugged into your radio.  The USB of course gets plugged into your PC.
3. Download the AGW Express Interface , also snag the documentation from there as well.
4. Run the downloaded file.  Follow along with the instructions, carefully.  There are a couple of spots where the answers to the installation choices aren't exactly obvious.
5. Once the installation is complete, you can run the AGW Express Interface and it will start all the pieces needed and then ask if you want to start RMS Express. Since you installed it as part of the solution set, of course you will start it.

That's all there is! Well, you need to get familiar with RMS Express, but also reasonably straight forward.  Just remember there are two parts the main screen and then the piece that does the send and receive.  This send/receive is started using the "Open Session" icon which looks like this

Previously, I was using AirMail as the packet client, RMS Express does both VHF/UHF and HF packet, plus it is being actively updated.  So it feels like a better choice.

Okay, I lied! There is one more thing you need and I bet you already asked... How do I get a Winlink email address?  Check out the How to get a Winlink RADIO e-mail account? It is fairly straight forward, but relies on you having the ability to connect via your radio to an RMS Gateway using your new packet setup. The information and links on this web page will be of immense help.  If you can find an local elmer it goes much quicker.

Good luck!  If you have questions, feel free to post comments or email me at K7RFH at arrl.net

Other resources:

• RMS Express FAQ
• Installation Of All Solution Components (Open or Save As)
• RMS Express Tutorial

UPDATE: 2013-12-18 AGW Express Interface Version 2 is now available