AmateurRadio.com

Courtesy: http://tomthompson.com/radio/projects.html

In response to an earlier blog about my recent neighbourhood noise problem, Matt (W1MST) , has passed along an interesting link to one ham's solution to a grow-op light source noise. Although I don't necessarily advise taking the same approach, W0IVJ's unique engineering skills may also provide an answer to some other amateur's noise problem, be it any type of ballasted noise-emitter. The rest of his website is well worth a close look as well.

Another type of noise problem was addressed in a posting to the topband reflector today by Don, WD8DSB.....the noise coming from a treadmill's, PWM speed-controlled DC motor.

" For many years my wife's treadmill caused strong interference on 160 meters when it was in use, and yesterday I was able to completely eliminate the RFI using a combination of two different filters (a commercial line filter that provides both common mode and differential mode filtering, and 14
turns of the power cord on a 2.4" OD Fair-Rite #31 mix toroid core based on
the K9YC hams guide to RFI document).

I created a simple website that documents my tests and the filters used,
and for those interested the website URL is:

http://sites.google.com/site/treadmillrfi/

The website contains a link to a video on youtube where you can actually
see the effectiveness of the filters. "
 
These two amateurs have developed slick solutions to their noise problems, but sadly, noise ingression is rising exponentially it seems and is becoming more and more challenging to mediate.
Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

When I got home from work last night, the temperature outside was 10F (-12C).  My basement shack was a relatively balmy 57F (14C). Just before it was time to go downstairs for the 80 Meter QRP Fox hunt, I changed from the "regular" sweatshirt that I was wearing to a "hoodie" type sweatshirt.

I plugged the earbuds into my ear holes, and pulled the hood up. I was able to remain comfortable, not quite toasty warm, but comfortable in the shack for my duration of the hunt.  I do have to admit that once I nabbed the second Fox of the night, Randy NC4RT at about 0244 UTC, I shut everything down and hightailed it upstairs. But as the tip was given freely to me last winter, I pass it on to those who may also need it.  If your shack is semi-unheated, as is mine, covering your head makes all the difference between shivering and operating comfortably.

It looks like the coldest weather of this round has left us. It actually warmed up overnight and was 20F (-7C) when I woke up this morning, but snowing. Until the next Vortex comes to visit (and I'm sure there will be more!) the basement should warm up to the low to mid 60F range (15-17C) and playing radio down there won't be so bad, at all.

72 de Larry W2LJ
QRP - When you care to send the very least!
Larry Makoski, W2LJ, is a regular contributor to AmateurRadio.com and writes from New Jersey, USA. Contact him at [email protected].

Shack – operating position Jan 8th 2015

As many of you know, I had a cerebellum brain bleed in Sept 2013 which was operated on. I am steadily recovering, but my voice is still poor so I much restrict operations using voice modes for now.  The picture shows the operating position in my shack. As shown, I am using 500mW on 10m WSPR (WSPR-AXE-CW beacon) and 5mW ERP on MF WSPR via a homebrew transverter (just below the clock) and the earth-electrodes in the garden.  MF uses the PC and FT817 whereas the 10m beacon is tiny and needs no PC. The loading coil (above the power meter) is not used with the earth-electrodes. It is used when on MF when loading up miscellaneous other antennas. It is not in use at all currently.

When fit again, I intend to resume field experiments.

Not shown are any of the optical, 136kHz or VLF kit or the bench used for building. The latter is currently awaiting better health again.

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

With the Bz component of the Interplanetary Magnetic Field turning southwards yesterday, an unexpected incoming stream from the sun was able to interact more intensely with the earth's magentic field , producing some fairly active auroral conditions overnight. The 'K' index numbers rose as high as '7'...a rare event, indicating a major disturbance. By dawn, much of the activity was winding down and the ensuing F2 MUF spike was not far behind.









Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

My first ever RX outings on 2m were with a derivative of the CQ2 super-regen RX circuit from Practical Wireless back in the late 1960s. The very first signal I ever heard on 2m was G3VEH/P on Caradon Hill in Cornwall. I was located at Kingsbridge in South Devon. I used a small crystal earpiece and a 19 inch whip. The same receiver was later adapted with the addition of an RF amplifier in my Fredbox AM transceiver. These were the days when AM was still king on 2m. The best DX contacts with the 10mW Fredbox were impressive.

A few years ago, I rebuilt my Fredbox and had a few local QSOs on 2m AM. It still works well for something this small and simple. More details of the Fredbox are on my website. Follow the link above.

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

A conversation has started on the QFOX reflector amongst the Hounds and Foxes. We're sharing with each other what our antenna situations are.

Myself, I am using a Butternut HF9V which is ground mounted and had about 55+ radials running from underneath it.  I also have an 88' EDZ which is up in the trees somewhere between 25-30 feet (8-9 Meters) up. My W3EDP is still up there, but I need to change the coax. Still haven't done that, but will, someday.

If you look at the standings in the Fox hunts, come the end of the seasons, you will find W2LJ firmly ensconced in the middle or just below the middle of the pack. I suppose if I had more wire up, higher - that could possibly change.  But what I have is what I have, and for that, I am grateful.

There are a lot of Hams out there who would consider what I have to be the "best antenna farm - ever". These guys live in places where their antenna possibilities are either severely limited, or perhaps not allowed at all. Some may even be restricted to operating portable 100% of the time, from their cars or local parks, perhaps.

So I am always mindful to be appreciative of what I do have - particularly when I find myself falling into that "wish I had more" rut.  It may not be as good as what a lot of others have, but it's also a lot more than what a lot of others are forced to live with.

72 de Larry W2LJ
QRP - When you care to send the very least!

BTW - To all my Orthodox friends out there - Merry Christmas!
Larry Makoski, W2LJ, is a regular contributor to AmateurRadio.com and writes from New Jersey, USA. Contact him at [email protected].

Happy New Year!

2015 has started with some important developments. Ofcom have launched a consultation on draft regulations for new wireless telegraphy legislation. The proposals are intended to strengthen regulatory power and keep pace with technological advances with respect to interference of radio communications from electronic devices.

Current Electromagnetic Compatibility (EMC) regulations should prevent electrical and electronic apparatus emitting electromagnetic energy that would cause interference to radio communications but as most licensed operators have experienced this is not the case. In particular the growth of "power line" networking equipment (PLT) in recent years has caused much distress to amateur radio particularly in populated areas. I myself have suffered interference from what I believe are PLT devices.

It is certainly true that most newer devices are much better and are notched to prevent emissions in certain bands but there are still many older devices in use and imported non-compliant devices are still readily available. It is not just PLT devices that cause issues but solar panels with RF noisy inverters, unfiltered switch mode power supplies, plasma televisions and other equipment that pollute the spectrum.

Unfortunately at present Ofcom has limited enforcement powers so are proposing the law is amended to make it a criminal offence to continue using equipment identified as a source of undue interference.

Several agencies such as GCHQ, CAA and emergency services have voiced concerns in the past over the threat of RF pollution (Telegraph newspaper article) so not surprisingly this weeks announcement has been given the 'spooks' spin with some sensationalist headlines "You could be prosecuted over your broadband thanks to GCHQ" as the Telegraph reported.

I feel it is important that UK licensed amateurs respond to these proposals and the consultation is only open till next month it is very easy to respond on line at the Ofcom website. 

It is quite a timely announcement from Ofcom since I have been forced to use the QRM eliminator that I purchased back in August due to increasing interference. I have not been able to use it in line with the FT857D as it requires the PTT/TX-GND signal from the CAT/Linear socket from the transceiver to activate a bypass when transmitting. The issue being I wished to use the CAT functionality at the same time and this involved making up a harness with the appropriate 8-pin mini-DIN plug/socket. I purchased some plugs and sockets but kept putting it off due to the fiddly nature of the small connectors and I didn't wish to cause any damage to the FT857D by shorting the pins.

By chance I spotted this cable on eBay which is the same as my current CAT cable but with the addition of the PTT/TX-GND signal on a short pigtail with a phono (RCA) socket making it a breeze to complete the installation.

I am hoping to improve the noise performance by putting up a new HF antenna in the future, to this end I have had a nice Christmas present. A Feature Tech AW07A HF-VHF-UHF Antenna Analyzer


Once I have used it in anger I will post a proper report, but it seems a great piece of kit with some encouraging reviews, currently available of £168 on eBay it is a massive £200 less than the identical MFJ-266
Andrew Garratt, MØNRD, is a regular contributor to AmateurRadio.com and writes from East Midlands, England. Contact him at [email protected].