Final repairs on MFJ loop

Time to repair the control box.
It seems that almost all the bugs have been ironed out with the MFJ 1788 loop antenna. I sure have had an adventure with the unit but things seem to be on the upswing now. Some of the indicators the MFJ loop gives you when your match is good are High noise level meaning you are in the ball park. The SWR meters on the control box that visually tell you the SWR is good. Finally there is a tone that comes from within the control box when you are auto tuning the loop. As far as I am concerned this tone is only within the range of our cat Oliver's hearing. UNTIL........one day when I was tuning the loop in auto mode and all was going well until Julie tapped me on the headphones saying "can you not hear that ANNOYING sound!! I took my headphones off and still nothing it was not until I put my ear right up to the MFJ control box could I hear the tone. WOW my hearing must be way off  as Julie said it was very noticeable to her in the living room and to add insult to injury she also heard it over the TV. Needless to say this event happened a few more times and
Ready to remove switch
it seemed apparent that it was time to cut the wires to this speaker. While I was in there I also had to replace a switch that controls the range of the watt meter on the MFJ control head. The original switch did not work very well at all and MFJ was kind enough to send me 3 extra ones. Cutting the wires to the speaker (I could never hear) was very fast and easy but for this switch to be changed most of the unit would have to be taken apart it seemed. Once I was ready to remove the old switch and replace it with the new one it was very easy........having said "easy" it means that with the right tools it was easy. I used the Hakko 808 de-soldering gun and believe me this unit makes very easy work of removing the old solder. To the point were the defective switch just falls out of the board. In the past I have used the hand held de-soldering pumps and the wicks as well but nothing works as well as this unit. The solder station I have is the Weller WES 51 and it has served me well for many years and you can change out the tips for various jobs you want to do. So with the wires cut to the speaker and the new switch installed it's now time to just operate and no more (I hope) fooling around with the antenna.
A great tool to have


Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

Events in Ukraine

I have just got off the air after making several  contactsintoRussia and Ukraine on 10m PSK31. Ham radio transcends political boundaries and engenders friendships betweenpeople of all nations. All politicians could learn from it. My thoughts today are particularly with my radio friends living in Ukraine I hope that peace and normality are restored soon

до свидания!


Julian Moss, G4ILO, is a regular contributor to AmateurRadio.com and writes from Cumbria, England. Contact him at [email protected].

Cheap GPS module

Several of the Arduino projects I have been experimenting with have used a GPS module to provide accurate time and/or location information and in the case of the QRSS/WSRP QRP beacon a highly accurate GPS derived 1 second pulse is used for frequency calibration. A number of people have enquired about the GPS module I am using.

Most GPS devices have a limit on the altitude they work at, normally 60,000 feet or less. This is a legacy of the now defunct CoCom (Coordinating Committee for Multilateral Export Controls) restrictions. For my HAB project this restriction needs to be disabled and the GPS must be switched into 'flight mode' In the HAB community the favoured devices are made by U-BLOX

Therefore when I was sourcing a GPS I had search specifically for a inexpensive device using a U-BLOX.

s
The GY-GPS6MV2 as supplied
I soon found something called a GY-GPS6MV2, it appears to be a generic design and is readily available on eBay from suppliers in China, Hong Kong and Singapore and can be purchased at the moment for around than £10 (approx $15) including postage!

It is also available from domestic suppliers but often at a much more inflated price, but you don't have to wait several weeks for them to be delivered.

There are many other GPS modules available but this module seems to be one of the cheapest available. it is often listed as a NEO6MV2 GPS Module Aircraft Flight Controller.

The module consists of a small PCB 25mm x 35 mm size with a separate ceramic antenna connected by a small lead which is 25mm x 25mm in size. The Antenna is quite heavy and isn't suited to Pico HAB payloads but for other uses is more than satisfactory.

On the board is a small button-cell battery to provide backup to the GPS chip and a small EEPROM connected to the GPS chip which I believe can store configuration(s). I haven't used it myself just using the module in it's default set up at the moment. For a schematic click here

The board has four connectors VCC, GND, TX (Transmit) and RX (Receive) and can be powered by the 5V supply on Arduino boards since it has a small regulator to provide the 3.3V needed. 

In most projects all that is required is data out of the GPS. The GPS TX (data out) being connected directly to the microcontrollers RX (data in) The (0V and 3.3V) level shift of the signal is compatible with the TTL input of the microcontroller.

The GPS by default will start up and output standard NMEA sentences at 9600 Baud, until GPS position lock is achieved the NMEA sentences won't have a long/lat location. The module also has an LED which will start flashing once a lock is achieved.

There is no direct connection for the highly accurate 1PPS (pulse per second) signal that can be used for frequency calibration, but the flashing LED is driven by pin 3 of the GPS module which is the 1PPS (pulse per second) signal required.

The 1PSS signal, like the TX is either 0V and 3.3V, in order to use it a small lead will need to be soldered onto the board, either directly onto Pin3 of the GPS chip, or alternatively on to the small current limiting resistor used by the LED, as indicated below.

Showing the GPS 1pps points


Andrew Garratt, MØNRD, is a regular contributor to AmateurRadio.com and writes from East Midlands, England. Contact him at [email protected].

Try something new: JT9

Why? Because JT9 is the best weak signal mode there is. On 10 meters I worked with 5 watts JT9 CX2AQ (11.371 km) and LU8EX (11.445 km) I read at PE4BAS that KB2HSH published a nice list about the sensitivity of digi modes. Why should anybody uses RTTY for instance?

JT9 and JT65 are the most sensitive ones. I prefer JT9 because it has a very small bandwidth. Ideal for crowded band activity. At the moment activity is a bit low with JT9, so I call all radio amateurs who like to work QRP or low power and wanted to do some experiments: use JT9. Download the software from this web site of K1JT Joe Taylor.


Paul Stam, PC4T, is a regular contributor to AmateurRadio.com and writes from the Netherlands. Contact him at [email protected].

Out and About – Part 1

Finally a chance to take out my Shack-in-a-Box and do some outdoor operations. The weather for Friday and Saturday was predicted to be very good, with Saturday being the sunniest. It turned out to be the other way around, because on Friday morning I took my son to his baseball practice and set up the MP1 in a quiet corner of the field, under a blazing sun. With my deck chair positioned under some trees I took this selfie…

20140228-baseballfield-2
It being a Friday the bands were quiet. I worked JR1CXW from Japan on 15 meters in CW and had a nice long QSO with him. Then nothing till almost an hour later when I heard KZ5OM coming in on 12 meters. Because I had already marked the different bands on the MP1 tuning coil it was a breeze to get the antenna into resonance and work him. He came in 559 and I got over the Pacific with a 539 signal. Yeah, two firsts: one for CW QRP across the Pacific and one for CW with the US on 12 meters. Thank you Jerry, great working you.

After that V85TL and JQ2IQW who was interested in my QRP setup. I got some attention from a parent and gave a short demonstration. The exchange with BH1FXN was just a 599 one, but it was enough to impress him.
20140228-baseballfield-1
The sun was shining, the temperature just right and the coffee well brewed, so a perfect Friday morning. To be continued….


Hans "Fong" van den Boogert, BX2ABT, is a regular contributor to AmateurRadio.com and writes from Taiwan. Contact him at [email protected].

Simi Settlers Amateur Radio Club tours the USS Iowa (BB-61)

The Simi Settlers Amateur Radio Club in Simi Valley, California toured the USS Iowa, worked some DX, and got some great lessons about shipboard life. What an interesting history lesson in this video taken by club president Rick Galbraith, W6DQE!

USS Iowa, lead ship of a class of 45,000-ton battleships, was built at the New York Navy Yard, Brooklyn, New York. Commissioned in February 1943, she spent her initial service in the Atlantic and carried President Franklin D. Roosevelt to and from Casablanca, Morocco, in November 1943. USS Iowa is presently part of the Reserve Fleet.


Matt Thomas, W1MST, is the managing editor of AmateurRadio.com. Contact him at [email protected].

An Old Buzzard’s Guide to Getting Started with HSMM-Mesh

Getting started with HSMM-Mesh™ (High Speed Multimedia-Mesh), also known as Broadband Hamnet™, can be daunting to hams that have the interest, but lack the expertise of network engineers. Indeed, perusing comments and documents on the Web can be confusing to newcomers who want to participate in setting up Amateur Radio broadband mesh networks under FCC Rules in Part 97.

Read the rest of this post


Alex Mendelsohn, AI2Q, is a special contributor to AmateurRadio.com.

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  • Matt W1MST, Managing Editor