AmateurRadio.com

Series Three Episode Twenty-Three of the ICQ Amateur / Ham Radio Podcast. News Stories include:

CQ DX Marathon 

Ham radio team sets 7,000 QSOs target

The 'Worked All Winnipeg' Award 

Amateur Radio Club seeks you! 

Essex radio amateurs use satellites for JOTA 

Impending changes to the 5MHz beacon chain 

More Wouxon ham radio gear available 

134 GHz Amateur Radio Beacon proposed 

American Red Cross offers Amateur Radio course 

Team Thunderbox - a special amateur radio group 

Redcliffe Radio Club gets new repeaters

Closure of VK7AX packet BBS network 

Radio amateurs needed to restart RAYNET group 

Zimbabwe police raid on shortwave sets

New 500 kHz permit in the Czech Republic

Your feedback and Martin (M1MRB) reports on the PMR Conversions.

Colin Butler, M6BOY, is the host of the ICQ Podcast, a weekly radio show about Amateur Radio. Contact him at [email protected].

By his description of who he talks to it must be an 80 meter phone rig.  :-)  If only neighbors took this much interest in radio today…

Recently I began a project for a wire vertical antenna and it called for a 20 ft fiberglass or non-conducting pole/mast of some sort. Not to worry as I have a trusty 20 ft Jackite pole in a nice green color. I put the antenna together but the vertical wire was too long and so there was considerable slack wire swinging in the breeze. After some head scratching, I measured my 20 ft Jackite and found it was only 18 ft long!!! YIKES! Did it shrink?

Thanks to the internet, I was able to send an email to Jackite products and ask if that was normal. In a short time, I received a very nice response from the Jackite vp and an offer that was over the top and way more than I was expecting. It was more than I could accept as I’ve been quite happy with the product otherwise. Turns out that it was a small quality control issue that I can tweak and correct personally.

I get no monetary or other gain out of this, but did want to give credit where credit is due. This level of customer support is often lacking in today’s busy world. I am glad to give a shout out to this company and its products! They do the job and the company stands behind them with good service. Outstanding job Jackite!

72,

Kelly K4UPG PB #173

Kelly McClelland, K4UPG, is a regular contributor to AmateurRadio.com and writes from Florida, USA. Contact him at [email protected].

For readers local to my home area you may be interested in this exciting and free event in Ottawa this weekend. Full details can be found on the Artengine website. The essential details are:

Dates and times: Nov. 6th and Nov 7th, 12pm to 6pm.

Location: Arts Court 2 Daly Ave. Ottawa, ON K1N 6E2

If you are not sure what makers do or what goes on at a Maker Faire take a look at this video of the 2010 Kansas City Mini Maker Faire

Alan Steele, VA3STL, is a regular contributor to AmateurRadio.com and writes from Ottawa, Ontario. Contact him at [email protected].

Having an interest in weak signal narrow band modes, not to mention APRS which requires you to park your receiver on a specific frequency, I have always wished that the frequency readout on my radios could be relied upon. The QRSS band, for example, is only 100Hz wide. If your dial reading is out by that much, you’ll miss it completely.

Many people try to calibrate their transceivers using WWV but that is not often a very good signal over here, and what with all the other carriers around 10MHz – many of them locally generated – you can never be sure that you have tuned to the right signal. I have wanted an accurate frequency reference for some time so a couple of weeks ago, following a comment by QRSS enthusiast Steve G0XAR, I ordered an Efratom LPRO-101 rubidium frequency standard on eBay. It arrived in about a week.

The unit I bought cost about £50 and came with a plug for the 10-pin connector and a 24V switched-mode power supply. These second hand units are widely available. New, they cost over $1,000 even in quantity. They are used in cellular base stations and are manufactured to have a maintenance-free life of ten years. To ensure reliable service the cellphone network providers take the equipment out of service before the ten years is up after which it is presumably shipped to China for reclamation. The used units should have several years of life in them, especially in occasional amateur use.

Rubidium frequency standards work by locking a crystal oscillator to the very precise frequency at which the amount of light from a rubidium lamp dips due to a phenomenon known as the hyperfine transition. A synthesizer locked to a reference oscillator is swept through this frequency until the dip is detected. The LPRO-101 includes an oven for the reference crystal, circuits to detect the dip and lock the oscillator, an output that tells you when the unit is locked, and the frequency reference output at 10MHz. The connector also provides signals that can tell you the state of health of the rubidium lamp. Once that fails you may as well scrap the unit because it can only be replaced by the manufacturer at a cost far in excess of what you paid for it.

To use the LPRO-101 you could simply attach a 24V supply and connect a cable to the 10MHz output. However, it’s useful to have a circuit that shows you when the unit is locked on frequency. I used one shown in an article by KA7OEI built up on a piece of Veroboard, which uses a dual-colour LED to light red when the reference oscillator is unlocked and green when it is locked. You can see the circuit board inside the partially assembled case.

The voltage regulator and crystal oven inside the LPRO-101 generate a lot of heat so the unit is intended to be mounted on a heat sink. I purchased a Hammond extruded aluminium case to use for the project, which should provide reasonable heat sinking for the module.

One thing I learned from researching on the internet is that the LPRO-101 will run cooler when operated from its minimum recommended supply of 19V. This just so happens to be the output voltage of the power supply for an old Toshiba laptop whose screen failed so I decided to use that instead of the 24V supply that was sent by the seller.

The other thing I learned is that the rubidium lamps wear out with time. When they are made, the manufacturer ensures that they contain sufficient rubidium to achieve the stated maintenance free life of ten years, so the expected life in continuous use would be ten years less the use it has already had.

If I ran the unit all the time my rig is on – for example as an external frequency reference for a transceiver – then it is going to fail sooner or later. If I only use it for frequency calibration purposes, switching it on only when needed, then it will probably outlast me. The TCXO in my K3 is pretty stable so I should be able to obtain adequate accuracy for my purposes by manually calibrating the master oscillator using the rubidium standard and repeating this as often as necessary. How often that turns out to be, we’ll see.

Here is the finished unit. Annoyingly, I messed up the front panel of the rather expensive Hammond case. Originally I had intended to use an SMA socket for the output but I didn’t get the holes for its two mounting screws in the right place and after filing to fit it looked unsightly. So I fitted a BNC socket instead which is what I should have done in the first place. Unfortunately you can see the two holes for the SMA mounting screws either side of the BNC socket. So my frequency standard doesn’t look quite as professional as this one built by DL2MDQ. Oh well, it’s only a piece of test equipment!

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

Over the last few days, I’ve been using the scan feature on the FT8900 a bit more from the car. I’m scanning particular channels, rather than the whole of the band, but it’s interesting to see what coverage I’m getting. I’ll probably add more channels to scan when I identify likely targets of semi-distant stations to listen for.

I thought it might be fun to try and put together a Google Map of what I heard this morning – I’ve colour coded the different bands.

View Heard by G4VXE this morning in a larger map

As you can see, GB3CF up in Leicestershire is probably the most distant station heard this morning. It fights it out on 145.600 with GB3WR. But I didn’t hear WR this morning and GB3CF was clearly audible just around Abingdon for a few hundred yards.

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

I don’t know how long it has been around but I only discovered this online propagation prediction tool using the VOACAP prediction engine today.

It’s very easy to use, and produces a nice chart showing the best times and frequencies to use to make a contact with a particular region. Of course, the predictions are based on the average expected propagation for the month, it won’t tell you what the bands are like today, which is why it is better not to waste your time on tools like this and turn on the radio.

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