AmateurRadio.com

Having being inspired by one of Peter VK3YE recent video's, it was time to purchase a couple of kits and dust the soldering iron off the shelf and get down to building one:

This could prove to be a very useful piece of component test kit, for the constructor and repair bench, including the novice. It does, R, L, C  including ESR, Diodes and Transistors, giving the pin configuration detail of the Semiconductor device undertest as well as the useful gain figures. 







It is basically a copy of the Karl-Heinz Kubbeler design, centred around a programmable ATMEGA328 microcontroller which is very well documented. The kit took about 2 weeks to arrive from China, which contains a well made PCB, display module and all the components, including the blown main chip all for around £8.00 ($12 US). It comes with no instructions on how to put it together, but a Chinese manual is downloadable from the purchase site, which I will make a link available at the bottom of this Blog. Infact, really you don't need the manual for construction, as the component values are printed on the PCB, it just helps a little to get one or two things installed the right way around like the switch, and the circuit diagram can be useful for component reference and maybe fault finding later? Of course the Chinese manual is written in Chinglish, we are refered to welding not soldering! I don't think my old arc welder would prove very suitable for this project somehow? Hi!





I emptied all the components out of their anti-static packet into an empty biscuit tin, so I didn't lose any of them. I was away, it took around 2 hours of soldering, and sorting out the correct values, a DMM can help with the resistors values, as I found an orange band can look like a red, so its best to measure them to avoid confusion and getting one soldered in the wrong position. Transistors are marked to board values, and the marking of the outline makes sure you cannot put the devices in the wrong way around.

At this stage it is time to check the board over for shorts, man made solder links etc, and snip off component ends. All looked ok, time to connect the 9V battery, before inserting the main ATMEGA IC, at this point a DMM is required to check for regulated 5V at the IC socket pins 7 & 22, all confirmed correct and the regulator was doing its job!  
 
All in all it was quite a relaxing project to put together, I didn't find anything too difficult, although a bit of care is needed aligning up the pins of the main chip before pushing firmly home into its socket.




 



There is not much work to do with the display board as most of this is already constructed, just a strip of header pins that carefully require soldering in across the top of its PCB. This then mates up with the socket strip on the main board when it is pushed home and bolted together. 




All looked good time to switch on! If it fires up correctly one push of the On button should turn on the display. In my case it did, and didn't? When I released the Push To Make switch, it went out ? Some folk have had problems putting the switch in the wrong way around, I knew I hadn't done this and a quick check confirmed the switch had been inserted correctly, time to investigate further? The clue was the LED under the display board wasn't on, a quick check with the DMM around the circuit in this area confirmed my thoughts, I had put the LED in the wrong way, huh! Oh dear! I had to pull it all apart, split the two boards desolder and turn the LED around, and then put it all back together.








Great it then fired up correctly, and held in its On state after pushing and releasing the button, a quick adjustment of the contrast pot to get the display correct and all was looking well, time to calibrate..

To be continued in part 2.

References:

This is where I purchased the kit from, although they are available from ebay too:

http://www.banggood.com/DIY-Meter-Tester-Kit-For-Capacitance-ESR-Inductance-Resistor-NPN-PNP-p-929603.html  

Construction manual:

https://www.dropbox.com/s/zpjwo3vfv9yfr5b/SKU136841%20M8install.pdf


Design manual helps with Calibration and other stuff:

www.mikrocontroller.net/attachment/143813/TTester_096k.pdf

Newer version of manual:

www.mikrocontroller.net/attachment/164956/ttester_eng104k.pdf
Steve, G1KQH, is a regular contributor to AmateurRadio.com and writes from England. Contact him at g1kqh@arrl.net.

I was a mere lad of 12 with a burning desire for knowledge.  Our scout troop was in its infancy, I was only a second class scout working toward merit badges for 1st class scouting. I was also a den chief to a cub scout pack.

One of the merit badges I was working on was Morse Code.  As luck would have it, there was a commercial pipeline company working on a construction project thru the county. Among the employees of this company was a radio operator. I don’t recall his name but he was a ham and our scout master had convinced him to help some of us with learning enough code to qualify for the merit badge.

After a couple of weeks of learning the code there were about 5 of us who were interested in learning more than just the code.  We would regularly stay after the meeting to talk with this fellow about his hobby of “Ham Radio”.  He would tell us about the equipment, antennas and discuss the most basic theory of operation.  I was more than a little interested!  A couple of the guys even bought receiver kits from Allied Radio to be able to listen to shortwave broadcasts. There was this one kid who’s folks had a good bit of money and he bought both a Space Spanner and an Ocean Hopper kit from Allied.

The Ocean Hopper was a 3-tube super regenerative receiver using a 35W4 as a rectifier and the audio complement was a 50C5 and a 12AT6 as an RF detector.You could purchase 5 plug-in coils to increase the coverage from 165 KHZ to 35 MHZ.  There were connections for an external speaker the receiver also has pins for connecting headphones and a fahnestock clip to connect a piece of wire for an antenna.

The Space Spanner was a bit cheaper and only covered from 6-18 MHZ but this would easily cover all the commercial short wave frequencies in the 41 meter band as well as the ham bands of 40 and 20 meters. Utilizing the same basic circuitry as the Ocean Hopper the Space Spanner came with a built-in speaker and the 50C5 provided almost adequate output to hear weak stations.  With either of these receivers a good antenna with a proper ground would provide hours of pleasure just listening to all this new world of information.

As the weeks wore on I began to keep saving part of my weekly allowance of 50 cents along with my earnings from doing chores for my grandmothers and cutting grass. My goal was to get the $15.95 price of the Space Spanner along with a couple of dollars for a soldering iron and a few hand tools.The wooden cabinet was an additional $2.90!  With shipping costs from Allied the total cost for this rig would be just north of $20.00, quite a “princely” sum for a 12 year old kid who earned roughly $2.50 a week!

One night following our code lesson a couple of guys and myself were able to convince our instructor to let us see his “shack” as he called it. So off we went along with our Dads to see what this hobby called “Ham Radio” was all about!  As we entered his home he directed us to a room to the side of the living room.  Inside was the most complete compliment of radio gear I had ever seen!  Not only did he have his ham station equipment he also had all this commercial gear for the day to day communications needs of the construction company as well.  I remember watching him sit down in front of his ham station and flipping switches, turning knobs and all of a sudden the room was aglow with the illumination of vacuum tube radios!

I was absolutely speechless as the receiver came to life and the sounds of 20 WPM code came bubbling out of that massive 12″ speaker!  He then tuned to 40 meter phone and proceeded to make contact with another ham in Arizona.  Arizona!  That was hundreds of miles from my small town home in Southern Kentucky, initially I thought no way!  How could this box of wires, resistors, capacitors and tubes allow a fellow to speak into a microphone and talk to someone hundreds of miles away?  Seeing our amazement he then performed a trick that I still to this day consider nothing short of “magic”.  He took a small fluorescent tube, held it in his hand above his transmitter and closed the key.  To my amazement the tube actually begin to glow!  Needless to say I was “hooked” this was truly magic to me and from that night on I have been hungry for knowledge and more information about this scientific phenomenon!

Over the next few weeks the “rich kid” lost interest and I was able to secure the Space Spanner and the cabinet from him for 10 Bucks!  He had botched the assembly of the Ocean Hopper and had thrown it away!  Wow I bet I could have restored that one too but it was already in a land fill somewhere. I painstakingly followed the assembly directions and learned to read basic schematic diagrams while assembling the kit.  I was a bit nervous when I finally got up the nerve to “throw the switch”.  To my total amazement the little receiver came to life!  Sounds like I had never heard before came out of that little 4-inch speaker!

That was 1957 and today at the tender age of 69 I still have that little receiver along with my first transmitter, a little 50 watt Heathkit DX-20.  Once in a while I plug in a J-38 and turn this rig on just to enjoy how I felt back in the late 50’s as KN4MZW!

Although by today’s standards with the Internet, cell phones, tablet computers and instant gratification available at every turn, it’s easy to see that the hobby of “Ham Radio” isn’t nearly as mysterious. However, being able to call a friend across the oceans at will, have a long conversation while developing a lifetime friendship; all on a station that I assembled myself and did not have to pay an internet or cellular provider a single penny to accomplish, is still “Magic” to me!

Jack, W4JBR, is a special contributor to AmateurRadio.com and writes from Georgia, USA.

Partly because bandwidths are very low,  there has been a revival of interest in NBTV systems similar to the early TV transmissions by Baird in the 1920s and 1930s.

There is even a Televisor kit available for about £40 delivered (in the UK) with a CD with some still and moving images and its own test card generator. I am quite tempted!

The televisor kit is available for £35.94 + shipping from http://www.mindsetsonline.co.uk/Site/Home (search for televisor). This is compatible with the 32 line standard of the NBTV Association.  The NBTV Association home page is at http://www.nbtv.wyenet.co.uk/index.htm .

Bandwidths are audio only, so a tape recorder or CD are fine. Over the air transmissions only require audio bandwidths too. Of course, with just 32 lines don’t expect brilliant images!

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

Is the end in sight for Motorola?

See http://www.bloomberg.com/news/articles/2015-02-06/motorola-solutions-said-to-explore-sale-of-87-year-old-company .

When I was at work (I retired 7 years ago) Motorola was our greatest rival. Since coming into existence in the early years of this century, my own company Sepura has been in profit every year. The demise of Motorola is a salutary lesson never to be complacent. How the mighty have fallen.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

Recently, I wrote to the “Last Words” column in Radcom. I very much doubt my letter will be published. The main thrust of the letter is the (very negative) attitude of the RSGB to the AM mode.

My letter (as sent) is reproduced here. I’d be interested to hear your views.

At the present time G6ALB is experimenting with very low cost 70cms AM modules as the heart of a possible short range (3km) voice transceiver. We have had some success already.

“Thank you for publishing the latest Band Plans in the February 2015 RadCom. Although because of my poor voice (stroke) I tend to use digital techniques, I still enjoy the occasional outing using AM. Like many, I have worked transatlantic AMers on 29-29.1MHz with real QRP and simple antennas.

Yet again, one could be forgiven for thinking AM, especially 28MHz and up, is a dirty word at the RSGB.  AM gets no mention on 28MHz and 50MHz and gets a (begrudging?) comment as a footnote only in the 144MHz Band Plan when other modes get “centres of activity” mentions. For the avoidance of any doubt, AM is alive and well in the 29-29.1MHz sub-band. AM on the 144MHz (2m) band can be found on and around 144.550MHz. There has been AM on 29-29.1MHz for years and years and years! Yes, this is the all-mode section, but why not say this is the 28MHz (10m) AM sub-band? Also, why are 144MHz AM users asked to “consider adjacent channel activity”? AM should easily fit in 6kHz!!

Sorry, yet again, AM is being treated as a dirty and outdated mode. May I remind readers that ex-PMR AM rigs ripe for use on VHF can be picked up for virtually nothing and that there is room for AM on all bands from 28MHz upwards. AM has its enthusiasts on other bands too, but yet again the RSGB seems hell bent on killing off this mode. Why?

73s
Roger Lapthorn G3XBM”

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

Cambridge Punts

Every Tuesday I travel into Cambridge for my weekly U3AC course called “Maps in the Computer Age”.  I am enjoying the course very much.

Usually I drive to the “Park and Ride” car park at Newmarket Road and get the bus into town. The U3AC course is at the U3AC headquarters in Bridge Street, which is about 30m from where the punts are on the River Cam.  At this time of the year the punts are quiet. Come the summer and this spot is very busy. Cambridge has lots of foreign visitors when the usual students go home. If you see a foreigner with a map wobbling along on a pink bicycle it is a good idea to be well clear!

Round Church – very old building

From the punt place you can punt right up via St John’s, Trinity, Clare and Kings College.  Kings College Chapel is lovely from the river.   The secret is not to leave your punt pole behind. It is easily done. Luckily the Cam is not too deep. If you prefer, you can pay someone else to do the punting so you can just sit back and enjoy a timeless Cambridge moment.

Bridge St,  Cambridge

Some of the views have not changed much in centuries. The Backs in Cambridge are very beautiful and it is little wonder people travel from all corners of the Earth to visit this beautiful centre of learning.  It is all too easy just to take it all for granted. Certainly, when I worked in the city, I did.  Now being retired, I properly enjoy it. It is still a very beautiful city with fine very old buildings and the River Cam winding its way up behind the colleges. If you have never been, you are unlikely to be disappointed.

Many years ago I was with a friend who parked at the multi-storey car-park just off Bridge Street. We worked a VK6 (S.W. Australia) from the car on 10m SSB.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

At around 9PM on May 31, 1978 were the first KNOWN transmissions of Packet over Amateur Radio. The location was Bill Wong’s Restaurant in Montreal, Canada.

The Montreal Packet Net Group C/O:

Bob Rouleau VE2PY; Norm Pearl VE2BQS; Fred Basserman VE2BQF; Bram Frank VE2BFH; Jacques Orsali VE2EP; Ted Baleshta VE3CAF; Ian Hodgson VE2BEN; among others not mentioned.

They operated on a single 220Mhz channel using start-stop ASCII with the Ethernet CSMA/CD protocol. The protocol was modified for amateur applications by Robert T. Rouleau, VE2PY, and implemented by Fred Basserman, VE2BQF. Montreal Packet Net (MP-Net) Operated at 2400 bit/s using home-built modems.

A detailed description of the Montreal Protocol and hardware used in the experiments is given in the TAB book #1345 “PACKET RADIO” by Bob Rouleau and Ian Hodgson published in 1981. An interesting note is that the Montreal Modem design used the Exar XR-2206/2211 chip set. I am told that a sample of the Montreal Modem was sent to the Vancouver group (VADCG) in the fall of 1978 and it is probably no coincidence that the same chip set appeared in the TAPR TNC modem of which Doug Lockhart of VADCG had a hand in designing.

After an initial spurt of activity in amateur packet, Bob Rouleau and several others in the group turned to commercial applications for packet radio. The resulting company, DATARADIO Inc, today is building and marketing commercial packet radio systems around the world. A typical application is the Canadian Weather Radio packet service introduced some years ago using DATARADIO equipment specially designed for the application.

Bob was inducted in the CQ Magazine Amateur Radio Hall of Fame in 2003.

Jack, W4JBR, is a special contributor to AmateurRadio.com and writes from Georgia, USA.