Yaesu FT-817 Go Kit

Yeah, yeah, yeah. We've all seen Go Kits before. But as Go Kits go I think mine is "up there".

I am a fan of the Pelican case. Y'know the ones? Hard plastic water tight cases that can float and take a beating when traveling. They are usually filled with foam and have cutouts for the equipment they hold.

I bought an IM2200 from my local Best Buy electronics store for $100. This seems to be an average price for them. Ebay did not reveal a cheaper price. It comes filled with 2 layers of "pick-n-pluck" foam which allows you to create shapes by pulling squares of foam out.

In the above picture we can see the lower foam layer. I've created cutouts for the mic, mains PSU, PSU cable and antenna tuner cables. The small box in the top right corner is a Wolphi-Link interface. It's like a PSK31 sound card interface but for your cellphone/tablet. It will also get a cutout.

In this picture we can see the upper layer of foam which holds the FT-817, LDG tuner, spare battery, whip antenna and 1:1 balun. The egg box type foam in the lid also pulls out. I can get 25 feet of RG58 and a 50 foot dipole behind it and still be able to close the lid with ease.

Here's a video of me packing it all away into the case https://www.youtube.com/watch?v=NzgnMb5nZo8

Mobile HF antenna install

I have a 2013 Dodge Journey. It's equipped with all bands from DC to light. It has FM, D-STAR, APRS and HF as well as a few non ham facilities. The problem with the car is that the steel its made from is very thin. The roof for example, flexes with the stress of a VHF antenna. So you can imagine what happens with a tall HF antenna?

A common HF antenna mounting solution is to install a clamp style bracket onto the rear liftgate high up as near to the roof line as possible. This is not possible with my car as the rear liftgate is made of plastic. Plastic and antennas don't work together. One needs a rather large amount of metal underneath the HF antenna so as to act as the counterpoise.

Over the 18 months or so that I've had my vehicle I've tried various mounting methods the best of which was a rather large magnet affair that consumed quite a bit of the roof space. This in turn prevented me from using the roof for other purposes.

My friend Kathy, KT2F, has an expression; "Be a man! I'm a man". She is referring to her willingness to drill holes in her new car to mount antennas. She's not wrong. According to my friend Norman, G4WQS, "a good mechanical join makes a good electrical join". Drilling a hole into the metalwork of the car would create both strong mechanical and electrical connections but only where the metal is thick enough.

I needed to replace the brake light on the back of my car today. Removing the light cluster is a simple matter of removing 2 plastic buttons. That's when I saw it. I finally found a spot to mount the antenna. It's not the best place on the car but it has all the other boxes checked.

You can clearly see the grommet where the cable exits the car behind the light cluster. By dumb luck I had a bracket in the junque box that would fit between the light and the car. 4 holes and some rivets later the mount was installed and a SO239 type antenna connector was attached to the mount. The coax feeding the antenna will feed through the grommet into the car and then on to the back of the radio.

As you can see from the completed installation, it is quite tidy. Click the pictures to get a closer look.

The total job took a little over an hour and that included fishing the coax cable from behind the interior paneling in the back of the car. Tests while parked on the drive show a much improved tune time (I have a screwdriver type antenna) and a broader bandwidth. Indeed, I no longer have to keep retuning when on 40 meters (the lowest band the antenna will cover) whenever I go from one end of the band to the other. Band-to-band tuning is also faster. I can now jump from 40 meters to 10 meters without the auto tuning circuit in the radio timing out.

So now I can tell Kathy that I'm "a man".

Weather satellite pictures update

It was a very fine autumn day today. I spent most of the morning up on the roof messing about with my antennas. One of these said antennas was for my newly built weather satellite receiver chronicled here http://g7ltt.blogspot.com/2014/07/apt-weather-satellite-pictures.html

There are still a few kinks to iron out of the system and computer control needs to be added but you get the idea ...

It seems the clock on my PC is a little off too. I guess I'll be digging into the bowels of RegEdit to force the NTP update to happen sooner.

Take a look at http://www.g7ltt.com/wxsat/ for more pictures and a timetable.

GPS mini cape for Beaglebone Black

On a whim I bought a Beaglebone Black. Now what? I need more PC's like a hole in the head. So what to do with it? Nothing came to mind until I discovered one day that my home brewed NTP server had failed. Aha! A quick poke around the net revealed this howto. Stand well back folks.

I've been playing with the Ublox NEO-6x series of GPS receiver modules recently. They are super-simple to use and add to any project. They need only power, antenna and a serial port. So with the GPSRX being so small and simple to use a daughterboard or "cape" (why cape? UnderDog is a Beagle and he wears a cape) for the Beaglebone was a natural fit. (

The board consumes only one of the headers

The board sits on top of the BBB drawing power from it via the raw 5V line. I found that I had to increase the current on the 5V PSU that supplied the board so that I could get a reliable GPS lock but otherwise it worked first time. And as you can see below, my Linux terminal prefers it to the other available servers from us.pool.ntp.org

g7ltt@earth:~/Downloads$ ntpq -p
     remote                       refid            st t when poll reach   delay   offset  jitter
=====================================================================
*time.g7ltt.com             .GPS.            1 u    5   16  377    0.284    0.880   1.543
-tdp-ism01.exped    206.183.22.197   3 u    4   16  377   55.487  -61.764   1.003
+152-ism01.exped   129.6.15.28        2 u    9   64  377   31.547  -69.109   1.229
-upa-ism01.exped   206.183.22.197   3 u   15   64  377   43.276  -68.318   1.557
+810-ism01.exped   128.118.25.12    2 u    6   64  377   38.032  -67.287   1.023

The prototype board in service

The files in Eagle format ...

GPS Cape Mini.pdf

GPS Cape Mini.sch

GPS Cape Mini.brd

20dB or 40dB RF Attenuator

I have found that I need an RF Attenuator for my bench. My bench tools are primarily suited to QRP work and so whenever I have to mess with a 35W FM rig I find that my meters and sensors are inadequate. I've killed quite a few bits of test equipment by stuffing 50W of RF into a 5W power meter.

As part of a larger project to create a 0-500MHZ power meter I started with the attenuator. There's nothing special about this one other than perhaps the compact design. It can be either a 20dB or a 40dB device dictated by the resistors you populate it with. Indeed, if you buy the boards from oshpark.com you can make both variations for less than $5.

See how simple it is?

The attenuator will present a 50Ω load to the connected radio and with its 1/4W resistors should be good for small bursts of around 50W of RF. Adding 1/2W resistors should increase the power capability to 100W and allow for longer key-up times at lower powers.

The files are listed below in both Eagle and PDF formats.

20-40dB_RF_Attenuator.pdf
20-40dB_RF_Attenuator.brd
20-40dB_RF_Attenuator.sch

Credit card sized Arduino with Ethernet

I dunno about you but I find the whole Arduino board format very cumbersome. It can also get very expensive too. Frustrated with boards stacked on top of each other I decided it was time to create a smaller board format that housed my most common components: ethernet, I2C, 12v PSU and of course the micro processor itself. 

One can find anything on Al Gore's Interweb if one looks hard enough. It was not long before I discovered something that could be fashioned into use. It had a few minor issues but as I would have to design a board anyway it was a good jumping off point.

The completed board

My version differs from drj113's in that I have removed the DIP switches and replaced them with a dual header so that one can use the header for either analog inputs or as a DIP selector. I returned all the components back to normal size (some were SMD). I've also brought out all the unused digital pins to a header on the edge of the board and added a FTDI interface so that one may connect a serial programmer.

Well, it almost worked first time. I stuffed the PCB, uploaded a sample sketch that would connect to the Internet and .... nothing. Crap! I hate diagnosing circuits. But for some odd reason rather than get the meter out and poke on about the board I decided that the problem MUST be with the software. I get like that after a beer or 3.

I was kinda sorta right too! It would seem that there are in fact 2 different libraries for the ENC28j60 Ethernet chip I'm using and of course, I had the other one. Easily fixed. I edited the library source code to reflect the moving of one of the signal pins used by the Arduino to talk to the Ethernet. It appears that the 2 libraries exist because of the addition of an SD card reader. The SD card would share some of the same pins as the Ethernet. To allow for both, the Ethernet pins get moved around a bit. Great! I fixed it. Upload the sketch and ..... nothing. 

Well, not nothing but not anything useful. I had established communication with the Ethernet chip but no further. This was proved by the reading of the Ethernet chip's version number and then the failing of any DHCP. CRAP!!!!

It turned out to be a trivial fix in the end but it took me over an hour to diagnose; I had neglected to add a pull down resistor onto one of the Ethernet controllers pins. 2K7 later and bingo! It did not take long to correct the PCB files and re-upload them to oshpark for others to use.

The final board with all the bugs ironed out

I've already pressed this board into service with my NTP shack clock. It works great!!

The design files in Eagle format . . .

Ethernet controller 1.1.1.brd

Ethernet controller 1.1.1.sch

Bitx DDS and frequency display

I built a Bitx20. I'm not happy with it. The VFO leaves much to be desired and whilst many folks find it acceptable I find it cumbersome and inexact. I never know what frequency its on. It appears that many users find this to be the case as is evidenced by the handful of digital VFO addons for the Bitx. Time to build my own.

So what do I want mine to do? Well, let's see . . .

• Arduino based (because it's easy)
• LCD readout
• Use cheap Ebay 9850 DDS module 
• CW keyer with paddle input
• FT-817 style computer control
• Channel buttons
• S Meter and battery voltage etc.
• Probably other things too

And here it is! It did not take too long to create. I borrowed much of the Arduino code from  other projects and hacked it all together.

The finished board

Observant bastards will have noticed the MIC and PTT inputs on the upper right of the board. This allows the PTT from the Mic to be wired through the board. The board will then compare the current frequency against it's internal band plan and then key the rig (or not). It will also display a TX or RX symbol on the readout.

The LCD readout showing the current frequency (upper line), battery volts (lower left), step rate (lower middle) and S-meter reading (lower right) 

The board under test

The IF + VFO combined output

The files ...

avr_dds_homebrew_i2clcd.pdf
avr_dds_homebrew_i2clcd.sch
avr_dds_homebrew_i2clcd.brd
BITX30_LCD_UI.ino
BITX60_LCD_UI.ino