AmateurRadio.com

Keeping it simple

I'm only 54 years old but over the past few years it's either my age or the growing of the hobby both technically and gadget wise that has given me some senior moments!! I really can't blame just the hobby as I have had times when heading to the car to only stop and wondering where is was I was heading too and for what! I'm comforted from online reading that says this is from having lots on the go and nothing to do with loosing your memory.  How does this relate to ham radio you say...........The rigs I have are the Elecraft K3 and KX3 both are menu driven as are many other rigs on the market are. I find myself going to the user manual or as I call it sometimes the "useless manual" to relearn a function that was just used the week before. I have had my ego get the best of me at times and refused to hit the books as I "knew" how to do this silly function command!! After going through several unknown menu's and not knowing how I got there, what I have done to the rig and better yet how to get the hell out! Oh and don't get me started on passwords that a whole other blog post!

3x5 life savers

For those of you who have the same memory melt downs at times as I do here are some helps that I use. In high school and University the good old 3x5 cards helped me learn (notice I said learn and not memorize very big difference) and pass many a test. The 3x5 helped me in the past and is doing so today, I write down step by step instructions for anything ham related items so I can refer to the card and not the Advil bottle. I cover over the card with clear tape so it will last for some time and the only thing I have to do is keep the cards in a place I can remember.....but maybe there is a card for that...:)). Just today I wanted to charge an external battery for my KX3 as I was going to do some hamming this weekend. I pulled out the battery and for the life of me I could not remember the setup to charge this darn battery. Thanks to a fellow blogger Larry W2LJ who has the same battery set me on the right path with an email. Now the instructions (simple as they may be) are taped on the side of the battery. 
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

My excursion onto JT6M last night was a bit fraught, although ultimately very worthwhile and enjoyable. When I fired up WSJT, it errored – saying invalid number of channels.

I realised it was probably something to do with the fact that I had installed the VB-Cable audio driver onto the PC to route audio from the FCD to other applications. No worries, it’s just a simple case of adjusting the various device numbers.

Except that it wasn’t. Everything I tried still came up with the same error. WSJT-X was still working ok as was PZTLog, so I knew there wasn’t anything wrong with the interface or cabling. I disabled the VB-Cable driver, which put device numbers back where they originally were.No.

Starting to doubt my sanity which has been in question recently, anyway, I Googled it, realising that it was one of those times when the error was not what it seemed to be.

Fortunately I found this thread – thank you N0RQ! It looks like this can happen when you add or remove audio devices on your machine.

Deleted the WSJT.INI file, restarted WSJT, which of course creates a new INI file – entered my defaults and all was well!

A frustrating hour, but easily fixed once you know…

Tim Kirby, G4VXE, is a regular contributor to AmateurRadio.com and writes from Oxfordshire, England. Contact him at [email protected].

The night before last Olga and I nearly jumped out of our skins after a tremendous thunderclap which sounded as if it was just a few feet away. I wasn’t concerned for the radios as I didn’t think attic antennas would suffer from a lightning strike unless the house itself was struck  but in any case  both antenna switches were in the grounded position after I had heard thunder a few days earlier.

I checked both the K3 and the FUNcube Dongle which was the only other radio connected to an antenna and both seemed to be OK so I thought I had got off scot free.

That afternoon Olga noticed that the Netgear DECT Skype phones were not displaying the amount of money in the account. Later I tried to make a Skype call and was informed that Skype was offline We could still make landline calls from the phones but only if we dialled manually. Any attempt to call a number in the Contacts list  using the landline received the message “The number you have dialled  has not been recognised.”

Poking the Netgear base unit’s Reset button with a sharp stick didn’t solve the problem. It looks as if the SPH200D base unit is broken. I’m rather sorry about that because it’s an obsolete product and new ones are unobtainable – although eBay has a used one on offer for  several times what it cost when new.

Olga uses Skype a lot to talk to relatives in Ukraine so it was very useful to have Skype connected all the time and not just when she was using the computer, but it’s looking as if we will have to live without that facility.

That evening we turned on the Humax Freetime box to watch some TV  and there was no picture. We checked the voltage from the power supply, which is a small 12V 4A  “brick rather than internal switched mode supply. Zero volts. We checked the fuse and that was intact. Unfortunately the Humax power supply has an unusual type of plug so I can’t use one of the collection 0f wall warts that I have in a box in the garage to test if the satellite receiver itself is working or whether it’s just the power supply that has failed.

There is no proof that lightning really did cause these items of equipment to fail – everything else including the broadband router are still working – but it’s quite a coincidence it it isn’t.. SoNow all I can do is wait until next week and order a new power supply from Humax. Oh happy days! At least we can still watch TV as I kept the old Freesat box as a backup.

Postscript. According to a neighbour a house a few streets away was damaged by the lightning bolt. Doesn’t seem near enough to have blown up two items of equipment though.

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

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

How has the radio year 2013 been to you? Have you made additions to your shack? Did Santa bring you unexpected toys this year? 

John Smithson, Jr., N8ZYA, is a regular contributor to AmateurRadio.com and writes from West Virginia, USA. Contact him at [email protected].

This evening, I was watching the tweets go by and realised that it was the peak of the Quadrantids meteor shower. Not having a 2m beam up at the moment, the only possibility was 50MHz. And though I have got my old 50MHz beam back from a friend who had it on long term loan, it’s not in a state to go up at short notice. So the only game in town is the V2000 vertical.

I wasn’t too worried as I had heard a few meteor bursts on the vertical in the past, so I guessed if there was any reasonable activity, I might hear something.

I quickly saw some bursts from an SM7 station and then a very considerable number from SK0TM up in JO86. So many, that I decided to go up to the shack, having been monitoring it all from the comfort of the sofa on the iPad.

Very much tongue-in-cheek, I started to call SK0TM with a report. To my enormous surprise, I very quickly got a R26 report back so was able to send Rogers and receive them. By the time we got to try and exchange 73s, the conditions seemed to have dried up, but we both had all we needed for a complete QSO.

Thank you, Stig – I know it’s possible to make MS QSOs using simple aerials, but I’ve never done it with a vertical before!

Tim Kirby, G4VXE, is a regular contributor to AmateurRadio.com and writes from Oxfordshire, England. Contact him at [email protected].

Yes another day, another Arduino project (seriously this is a great development environment)

As I mentioned in passing yesterday I have a number of Arduino based projects buzzing around in my head. One of them is to produce a satellite antenna pointer/indicator.

I have used an Android AR tracking solution before (flaky at best) and can see the relevant information in Orbitron or SatPC32 to know where to point the antenna but it is difficult to see a PC screen when stuck out in the middle of the lawn!

My idea is this, I will make a large tripod to which I can attach appropriate antenna as I need, then during the satellite pass it has indicators to show where to point the antenna manually.

I envisage the azimuth indicator to be a large horizontal circle with 36 LEDs positioned at 10 degree intervals, the elevation will be a quarter circle with 20 LEDs positioned at 5 degree intervals. Then during the pass the appropriate LEDs will light and assuming I keep the antenna aligned to these I should in theory get the best signal... Crazy??

Yes I know I could make or buy an azimuth/elevation rotator, eBay is full of low speed high torque geared DC motors with auto-stop/hold and numerous software solutions exist to drive them but this would require a bit more engineering and isn't something I can easily fabricate at the moment. My contraption would be much more rustic being made of rough cut timber!


Bright LEDs are ridiculously cheap and controlling this number from the Arduino will require the use of multiplexer drivers. The popular ones are the MAX 7219/7221

I won't go into the details of exactly what multiplexing is, other than to say that each display element (LED) is driven one at a time but by switching the electronics at high speed combined with the persistence of vision make the viewer believe the entire display is continuously active.

This technique can be used for individual LEDs, an LED grid matrix, or for 7 segment displays. Last night I successfully got a MAX7219 based 8-Digit 7-Segment LED module working.


The next stage was to investigate how an Arduino could calculate the appropriate azimuth and elevation data. Thankfully a library already exists qrpTracker (code is here), within this library is a port of the Plan-13 algorithm first written in Basic by James Miller G3RUH in 1990, subsequently ported to C by Edson Pereira, N1VTN and further updated by Howard Long, G6LVB.

Plan-13 processes keplerian elements, time and (optionally) observer location, and uplink downlink frequencies; it outputs satellite latitude and longitude, azimuth and elevation, and Doppler shifted frequencies. At the standard 16 MHz Arduino clock speed, this code can complete these calculations in approximately 30 ms. This code is reported to be highly accurate, if provided with proper data.

The important data are the observer location (longitude/latitude) and the current time. Step forward my well used GPS module which once lock is achieved can supply that data.

The next is get the appropriate up to date Keplerian twin element sets (TLE) and extract the appropriate information from it and pass that data to the Plan-13 functions.
 
The standard TLE follows the following format

You need to extract the Epoch Year/Day (including partial data), Inclination, Right Ascension, Eccentricity, Perigee, Mean anomaly and Mean Motion for a calculation (drag/orientation aren't critical) For the moment I have just extracted this manually from the latest TLE and entered it directly into the program.

After just an hour or so of research and programming I have the LED displaying the current azimuth and elevation of the FUNCube-1 satellite (AO73) based on the current position and time derived from the GPS!


The first four digits is the azimuth, the second four the elevation.

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