Low price 40m CW transceiver "frog sounds"

There's a very low cost CW transceiver for 40m available out of China on ebay dubbed "frog sounds".

For just $19 including free postage you get a decent kit with circuit diagram. I put mine together in about two hours and it worked first go.

The circuit is available via this link. Basically it's a conventional NE612 LM368 direct conversion receiver. The transmitter ads a side tone generator using some NAND gates.

As I've observed before you can't purchase the individual components for the price of the whole kit and the board and documentation is decent.

Update not all smooth construction for some.

John, VK2ASU, sent this:

"Built the Frog Sounds transceiver today. Many problems and many hours spent trying to fix. Have it going to a degree. Getting 1 watt out on 12 volts compared to 3 watts on the previous one.

One major problem I found is that the holes are not all plated through perfect and this stopped the receiver until I found it. The rx works now but "deaf". More time and effort to go.

Decided to do a search on the net if others had problems. Yep!

Here is a link to look at and this.

When you solder a component in make sure you let enough solder to flow into the hole to work right through. There is a hole about in the middle of the board (when it's all built you will find). It is at the end of a track which then goes through the board to the underneath. I had to scrape insulation off both sides and add a wire through it.

For all that the circuit looks really good it's a shame that the board is so bad.

On the plus side the keying is crisp and the sidetone quite good."

Liking Google Photos

Google has done such a great job with Google photos that it puts Apple's equivalent to shame. Apple has had face identification for some time but the genius here is that it doesn't wait for you to name people, it just groups by face.

Now, for some reason this feature is disabled for Australian users by default. To enable it I followed the instructions here and used an Android device as they suggest. I used TunnelBear for the VPN and all went as described.

I'm currently in the process of copying 22,000 photos from my iPhoto and Aperture libraries up using Google Photos Uploader app for MacOS. Unfortunately, although I have 100Mbps download speed my upload speed is just 2Mbps and so the upload will take several days.

It would have taken much longer as the Mac goes to sleep when idle. To stop it sleeping during the mega-upload I'm running Caffeine which is free from the app store.

I hope Apple responds to this competition, they need to do the following:

• Offer an unlimited (image size capped is fine) photo archive
• Cut the price of their cloud storage (for 1TB: Google is $10/month, Apple is $25/month)

WWDC is next week but I doubt this is on the agenda. Interesting times.

Download this show wins IT journalism "best audio program" award

Marc Fennell does everything on this show, producer, presenter, interviewer, editor, music mixer and talent wrangler. All credit to the new generation of tech-savvy media stars. It's a privilege to be a very small small part of the show.

Congratulations mate!

Very low cost i2c LCD interface board

Listening to the marvellous Soldersmoke podcast I learned of these serial interface boards for driving an LCD display using just two pins of an Arduino. These boards are just $1 out of China on eBay. Amazing.

With some help from Brainwagon I was soon up and running.

The little board solders nicely on to the back of standard Hitachi LCD boards.

I'm stunned that China can manufacture stuff like this for such great prices. Everything I make will have a display.

SM1000 FreeDV in a box arrived

Very excited this week when the SmartMic 1000 arrived. This is a FreeDV digital voice codec in a very nice box. It's designed so you can hold it in your hand rather like a big microphone and just talk in to it to transmit and receive digital voice.

The case has 3.5mm sockets for everything and also an RJ45 socket for a single cable connection. It's like the Signalink boxes and has a similar internal jumper system for wiring it. I followed the instructions and quickly had it working with my FT817.

The button marked "select" on the front switches between analog passthrough (so you can hear what the radio hears) and digital mode.

To test transmission, I listen off air and decode with the FreeDV app. My scatter plot looks reasonable I think:

I can hear my voice decoded so the next step is some contacts on 14.236 where I'm listening and calling.

Notes: 

• Mic Gain control operates in reverse.
• Select button switches between analog and digital. On power on it defaults to analog.
• Back button isn't used.

Stephen, VK2BLQ, also has one of these and I was able to receive him on 40m, here's a snippet.

80m antenna, take 3

It's tough putting up a decent antenna for 80m. The sheer length involved excludes many amateurs without large blocks of land. My shack is at the back corner of the block and I've had several shots at this.

Mostly I've used an inverted V dipole hung from a large tree at the back of the block, actually in the neighbour's yard, but the legs of the dipole have to make right angle turns and run along the fences. Recently I tried a full length dipole along one side fence line - it transmitted quite well but was very poor at reception.

This week I tried an inverted L. A quarter wave length up as far as I can go in the tree and then pulled sideways and a bit down to a pole on the side fence. Early tests with Mal, VK2BMS, indicate that he's the strongest I've received him and I'm the strongest he's heard me.

An earth stake kindly donated by Robert, VK2ZNZ, provides an excellent earth (particularly with all the recent rain) and the antenna tunes up beautifully.

It may well be that it's all ground wave between our houses, although Mal is running a dipole, but we'll see in the weeks ahead how it goes.

Naturally, I'm thinking of how I can combine my interest in drones with ham radio antennas.

Flying a micro-drone with a video camera attached, here's a closer view of the tree.

Using micro-drones to inspect antennas is actually useful. Here we see the support of the top of the 80m inverted L. Just below you can see my 40m dipole's balun.

When there's not too much wind I can take the drone up quite high.

Mount Stromlo observatory visit

For my birthday I got to do whatever I wanted and of course a visit to the Mount Stromlo observatory in Canberra was top of the list. It's a striking location and we had a big sky above.

The site was devastated in the fire storm of 2003 and the wreckage is still visible. Melted motors.

Remains of telescope buildings.

It's a striking site that seems mostly to be visited by cyclists who ride up and down the mountain.

Oddly, my daughter who has lived in Canberra for over three years had never visited.

The cafe is closed but there is a display for visitors in the old manager's house that has a nice display including some melted mobile phones from 2003.

Vale David Crooks

I'm so sad to mark the death of my beloved step-brother David Crooks.

A wonderful man and dear friend. Last Thursday he was looking forward to a trip to Melbourne and later in the year to shows in London. Positive to the end.

Farewell my friend. Too soon.

Built a smaller quadcopter

A new build from parts ordered from China. This time I'm using the excellent OpenPilot flight controller. Here's an early flight in the back yard.

Thanks Cat for filming.

It's basically this "kit":
http://www.banggood.com/X240-Mini-Quadcopter-With-CC3D-Flight-Controller-p-954482.html

I didn't use their supplied power distribution board as I didn't have any documentation and had one at hand.

I used a Fly Sky 6 channel remote transmitter and receiver (these are great by the way).
Also a compact 3s (cell) Lipo battery.

One frustration is that the motors could not be bolted in place with the supplied components and I had to hunt around to get 2.5mm x 6mm bolts and some nuts.

The OpenPilot CC3D software is amazing and I don't have it properly tuned just yet but it's great fun to fly around the back yard. The motors get hot and give off a satisfying burning smell after a bit of use.

Wyong field day 2015 - Damp but entertaining

The weather wasn't great for the big feature of the Wyong field day, the car boot sale. The ARNSW Home Brew group had a great display and spent time chatting with interested visitors. Here's John VK2ASU with Mal VK2BMS:

I showed the OpenRadio SDR on the home brew table:

While I didn't buy anything there were gifts of useful components from John and Stephen which are greatly appreciated! Some things I didn't buy:

It was great to retire to the classy bar:

For some tea, Jatz biscuits and cubes of cheese.

Built a larger quadcopter

The tiny drones are great for indoors, but to carry cameras I needed something larger. A collection of parts and a 450mm frame was ordered and finally it's flying.

I'm using a Fly Sky FS T6 transmitter and receiver and a KK2.1 flight controller.

Neither the remote or controller came with the interconnecting cable so I'm using single wire jumpers until proper cables arrive. The flight controller was recommended by Terry and is great because you can test everything and tune it by using its built-in LCD display and buttons.

While I can fly this thing the PI tuning isn't right and I'm getting oscillations while hovering. Lots to learn. Lots to learn.

Tiny Quadcopters - Hubsan X4 and friends

We are having too much fun at the office (during lunch breaks) flying tiny quadcopters. The best of them seems to be the Hubsan X4.

A close second is a clone sold as the "Top Selling X6".

Both sell for about $40. The Hubsan you can order from China, the "Top Selling" is available at Paddy's Market in Sydney. Don't be fooled by the price saying $49 reduced to $45, they'll take $40 in a heartbeat.

For a little bit more, $50, you can get models with a camera:

Some drones like the UFO drone have a remote with buttons for taking still or video.

Great to have "High Agily Control":

The cameras are not great but kind of fun. Here's me checking the gutters.

The video is motion jpeg and seems to drop a lot of frames:

The trick to getting decent video with these tiny MJPEG cameras is to use a fast microSD card. Here's a recording with a Class 10 card and it's much better.

The motors are interchangeable and the other "consumable", the propellors, are available at low cost.

So far, I've learned:

• Fly calmly, avoid dramatic corrections, and you'll be fine.
• Expert mode, by pressing the left controller (mode 2) is more responsive and not really any harder to control.
• The motors do die - I had one that went stiff after a crash, but are pretty easily replaced.
• There is a "ground effect" and a "ceiling suck effect". Take off to about a meter in height and then get stable. Avoid the ceiling.
• It helps to calibrate the accelerometers - the instructions explain this in broken English but it's worth doing. I've heard that calibration in expert mode is better.
• If the video drops frames get a faster memory card. Class 10 works for me.

Flying indoors:

In a larger room:

Great fun.

OpenRadio SDR kit build

Linuxconf this year in Aukland had a radio track where a low cost software defined radio receiver with some limited ability to transmit was launched. My kit arrived last week.

The OpenRadio SDR is based around the recently popular Si5351 oscillator which is controlled by an Arduino Nano. It's rather like the Softrock design but because the Si5351 has extra outputs there is ability to transmit digital signals modulated with shift keying. The software includes a beacon mode that can send a short message in, for example, BPSK31.

The OpenRadio SDR kit is lovingly prepared. As you can see above, the components are clearly marked and the makers have been kind enough to be generous with extra components - in particular I tend to lose surface mount capacitors and resistors from time to time.

The construction guide is first class. While there is some surface mount soldering required - a challenge for me certainly, they've been kind enough to pre-solder two of the most difficult devices.

I didn't rush the build and spent a few hours on Saturday doing a bit and then going for a walk. For me, everything worked first go.

The software in the Arduino is a great start but here's where this is where work can be done. You connect over a virtual serial port and get a simple menu for controlling the board.

0.3 Jan 31 2015 09:37:39
Starting up Si5351... Got Rev ID 1

RX Frequency (Hz): 8986000
TX Frequency (Hz): 26959500
TX/RX Relay State: RX
Transmitter State: OFF
Calibration factor: 1.00000000

RX Frequency (Hz): 8986000
TX Frequency (Hz): 26959500
TX/RX Relay State: RX
Transmitter State: OFF
Calibration factor: 1.00000000

MENU:
1: View current settings.
2: Change RX Frequency.
3: Change TX Frequency.
4: Toggle TX/RX Relay.
5: Toggle TX State.
6: Start BPSK31 Terminal
7: RX VFO Mode
8: Calibration Mode
9: Save Settings
A: Set channel (TX/RX frequency pair)
B: Start Beacon

For tuning around, at the moment you must use RX VFO Mode which gives you keyboard letters for tuning up and down, rather like PowerSDR but you must press enter after each.

RX VFO Mode, press q to exit.

    Up: r   t    y    u    i    o    p

  Down: f   g    h    j    k    l    ;

Amount: 1   10  100   1K   10K 100K  1M

I guess an interesting direction to evolve this would be to implement the protocol used by a popular rig and then SDR software could use Hamlib to control the board - certainly all possible.

My congratulations to everyone involved in this. I think it's a great idea brilliantly executed and I can't wait to see what people build on top of it. The idea of having an Arduino at the core makes it very accessible.

Raising antennas with a drone

Stephen, VK2BLQ, has suggested we try holding an HF vertical up with a drone but here's another idea for antenna installation in tall trees.

I'll have to improve my skills a bit but it's a great way to combine two hobbies.

Good value laptop for ham radio use - Lenovo X201

Recently there have been a constant stream of second hand Lenovo X201 laptops on ebay here. David Rowe mentioned when he visited that the X200 series is the last "good" Lenovo laptops from a technical Linux using perspective. Here's the one I picked up for $240 but they range from $200-$300.

I like these for the following reasons:

• Solid build
• Easy access to the hard drive - one screw and it pops out of the side.
• Old style boot, not UEFI, so you can install old Windows
• Fairly compact
• Tolerant of high RF (My old MSI netbook goes a bit crazy when transmitting)
• Decent CPU - i5 with quad core can keep up with DSP tasks

Mine came with a pretty dead battery so I paid another $40 to get a new 9 cell replacement. I had a 240GB SSD handy so I used a USB key with a gparted live linux system on it to dd copy the internal disk over to an external drive case and then swapped the drive. (These little bootable USB utilities are a very useful tool in the kit).

As you can see above, I'm dual booting Ubuntu for WSPR but also keeping Windows 7 around for the Windows only software I sometimes need to run.

Skypi 40m transmitter controlled by Raspberry Pi

Just saw this interesting gadget called a Skypi from RadWAV.

It appears to be a 1W carrier transmitter for 40m that plugs in to the GPIO socket on a Raspberry Pi. The board requires 12V and it produces 5V to power the Raspberry Pi board via the connector.

They've modified existing software to control the frequency and carrier so that it can transmit WSPR, RTTY and CW. For CW they can read a key plugged in to the board.

Note that this is not a transceiver, which is a pity. They offer an optional output socket for a receiver and the board switches the antenna to that port between transmissions - there's demonstration audio of how it sounds.

It's great that RadWAV has created this product but I'd really like to see at least a block diagram of it. The documentation is sent to you by email after ordering.

Personally, I'm hanging out for the OpenRadio SDR which is being launched at Linux Conf AU which starts on Monday 12th Jan.

The SkyPi kit is US$85 or US$185 assembled including the receiver output port.

Copper pipe loop for 40m

Inspired by the work of Peter, VK3YE, I visited the local hardware store to get bits for a 40m loop antenna. Purchased a 3m length of copper pipe, some hose clamps, some copper saddles, a piece of dowel, and a plank of wood. Here's the result:

The variable capacitor is clearly not going to be able to stand much power but at 20W it doesn't appear to be arcing. This capacitor has a reduction drive and I'm using a switch to add a bank so that I can tune both 40m and 20m. Joining the tuning shaft to a dowel rod with a piece of plastic pipe and cable ties worked out quite well although there's a little slippage.

Matching stub:

Tuning is incredibly sharp but a very low SWR is achievable.

The offset of the tuning stub was a guess but seems to be reasonably close to 50 ohms. I had a pre-arranged contact with Stephen, VK2BLQ who could hear me reasonably well.

Reception seems excellent and of course the very narrow bandwidth leads to nice low noise.

Update

Had a visit from Bob Bray who liked both the shed and the loop antenna, although I suspect he wasn't impressed with my impression of a circle.

Robert John Bray is a prominent astronomer who has been honoured by having a main belt asteroid named after him.

Update - motor drive tuning

I've changed capacitors and added a 36RPM motor drive and a box to switch direction. The drive is still way to fast and now I'm looking for a reduction gear or multi-turn capacitor of some sort.

Built an Ultimate3 Beacon

This week an Ultimate3 QRSS/WSPR kit beacon kit I ordered arrived and this morning it was easily built.

The display is super crisp.

I ordered mine with the 30m low pass filter.

The whole thing runs on 5V so I chopped an old USB cable and have been running it from a USB charger or battery.

It's a great kit, with very clear instructions and it came together very smoothly. Mine was missing one small capacitor but it was no trouble finding one in the shack.

The software is very well done and everything is set up using two push buttons placed in just the right spot for your fingers while holding the board with the display facing you.

Amazingly this does WSPR as well as lots of modes:

- QRSS mode (plain on/off keyed slow CW)
- FSK/CW mode (frequency shift keyed slow CW)
- DFCW mode (dual frequency CW)
- WSPR mode (Weak Signal Propagation Reporter)
- WSPR-15 experimental WSPR mode with 15-minute frames
- Opera modes (8 speeds)
- PI4 beacon mode
- Slow-Hellschreiber (frequency shifted slow-Hell)
- Full-speed Hellshreiber
- Half-speed ("DX") Hellshreiber
- CW (plain CW)
- FSK (0-999Hz shift, fast-speed FSK CW)
- Customisable FSK patterns
- manually-keyed CW/FSK transmitter

I ran Hellshreiber for a while but it didn't look too good on fldigi in the house, now I'm running 20WPM morse but that's not decoding perfectly either - my guess is that the signal is so strong that AGC is messing with it but I'm still trying to figure this out.

Useful M8 transistor tester

I purchased a transistor tester kit from AliExpress a few weeks ago and it's a useful gadget for the workbench.

Often when home brew circuits haven't worked it has turned out to be because I didn't get the pinouts on transistors right and this device figures out the EBC pinouts of a given transistor. It also analyses other components although not small values.

Cost about $25 landed.

Digital voice ove HF radio talk

This week the ARNSW Home Brew Group was honoured with a visit from David Rowe, VK2DGR, who spoke about codec2, FreeDV, and the upcoming hardware implementation called the SM1000.