AmateurRadio.com

2018 was one of the coldest Winters we have had for many years in the UK, followed by one of the hottest Summers, that brought out our shorts, burnt up our lawns, and farmers were talking up the price of food because the drought had caused the yield to fail, so they said anyway? But the crisis wasn't just down to the weather, the high street was under attack from changing times! Expensive rents, high business rates, the new living wage hike and shoppers that were migrating in droves to the Internet, that were being blamed for causing the end of famous names to quit the towns and cities and made to go bust. Getting caught up in all this mess was MAPLIN the last electronic major retailer of electronic components, gizzmos, electronic toys and computer components, on the high street. Stores were mainly confined to big retail parks, after they had embarked on a rapid expansion program in the late 1990's.     I had caught a smell of Maplin's demise for quite a number of years before the rumour had ever hit the fan. Everytime I had gone into a store, I kept asking myself how were they surviving, as very few customers could be seen in the stores when I had made a visit? Maybe they did well at weekends, Christmas and holiday time, but every visit I had made hardly a soul was seen? I have to admit, Maplin never filled me with much enthusiasm either, they were expensive! I never really bought much from them, but they were handy, if I was in the area and just short of one component to finish a project one had been itching to get going quick!   This one was the well presented store I visited at Walsall, West Midlands in early February. But already there was a sign something was not quite right, shelves were begining to look empty and not being refilled, the rumour was already in the air.   By the end of February the game was up, Maplin was surrendering, the receivers were called in to try and save jobs and stores. How did they get it all so wrong? Whatever Maplin was doing, was already being done, by the likes of RS and CPC for next day component delivery, or if you were the small constructor willing to wait a couple of weeks an abundance supply can be had from Ebay and Chinese sellers and the likes of Banggood. Store closurer came quite rapid, nothing could be done to save over 200 stores and all the jobs that went with them, the shutters were finally brought down on the whole operation by the end of July 2018 all was closed, or was it? Out of the ashes the name survives and has been bought by Dragons Den Tycoon Pete Jones, already the Website is getting ready to run again  and the name is alive once more here: Maplin!  What will 2019 bring? A Happy New Year to you all.  
Steve, G1KQH, is a regular contributor to AmateurRadio.com and writes from England. Contact him at [email protected].

Ham College episode 48 is now available for download.
General Amateur Radio Exam part 19. Overmodulation and Test Equipment.

1:16:01

Download
YouTube

George Thomas, W5JDX, is co-host of AmateurLogic.TV, an original amateur radio video program hosted by George Thomas (W5JDX), Tommy Martin (N5ZNO), Peter Berrett (VK3PB), and Emile Diodene (KE5QKR). Contact him at [email protected].

Well Christmas has past and now it's the New Year that is being pushed with the full force of the media.....join a gym, loose weight and change your career. I'm good with all three of the mentioned BUT lets get back to Christmas shall we........ or to be more precise about a month before Christmas. My wife has been listening to me "mutter" now and then about my ham radio adventure. My blog readers are well aware of my purchase of the Expert Electronics Sun SDR2 Pro SDR transceiver. I was thrilled with the rig and how it preformed was amazing. I did mention how I truly missed the knobs and dials of a "real" radio but at the same time it was somewhat worth giving up for the
waterfall, SDR funtionality and 2 independent receivers. Little did I know Julie was listening to my now and then comments about radios as I read QST. My wife who is not a ham and has made it very clear she has no interest in radio what so ever but she was able to hear my interest in SDR radio and my missing an actual rig put it together and get in touch with our local ham radio dealer. The pictures tell the story of what was under the tree on Christmas morning!!
There is going to be an Expert Electronics Sun SDR2 pro rig that is just over 6 month old up for sale very soon.
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

Well G3XBM is always reminiscing about his time at PYE, I wish I could do the same for Thorn Automation days, but as most of the work was restricted very little of their products have made it into the Amateur world. .

Rogers recent ramble here made me reach for the desk drawer. Out I pulled a PF1 receiver still complete with case.



I cut my teeth on a PF1 with my first taste of 70cm receive back in the early 1980's. What I seem to remember I picked  up quite a few of these at a radio rally for about £5 each! But the crystal was about the same price again, which was required to replace the original to get them working on one lonely channel, or tuned up on a single repeater frequency, in my case being Stafford GB3ZI (433.275MHz). What I seem to remember tune up was quite a fiddle, they used to break into oscillation, as the pull was quite a bit out of the zone of where they had originally been working in the commercial world.






This one has seen better days, but most of it is still quite complete apart from the metal shield over the front end. The battery was rechargeable 9V long time expired, but soldering in a 3F23 or PP3 would make it burst into life. So as you can see I have been around quite a while to remember the older PYE generation, but not quite as long as G3XBM. :-)



Steve, G1KQH, is a regular contributor to AmateurRadio.com and writes from England. Contact him at [email protected].

Original shape of coupling loop

My last couple of posts have been dealing with extending the bandwidth of my MFJ 1788 loop antenna. With the loop the lower the SWR the more bandwidth I  have before I have to retune the loop. Up to this point I have tried moving the antenna ALL over my balcony and the best SWR at that point was at best 1.6 with the loop in the horizontal position. I then gave the loop a go in the vertical position something I had never done before. I was surprised that the loop had a better SWR, I was able to get it down to 1.4 SWR. One last suggestion given to me was to adjust the internal 10 gauge coupling loop. Today I took the section of the cover off that exposed this coupling loop and moulded the loop from it's "0" shape to more like an egg shape. with doing this I was able to lower the SWR do 1.2 to 1.3 depending on the band I was on.

New and improved shape

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

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Now, thanks to AmericanRadioHistory.com, most of those great old hobby magazines of the past can be viewed online and enjoyed once again.

As a pre-teen short-wave listener in the late 50's, I couldn't wait to get my hands on the latest edition of Popular Electronics, stuffed with its latest SW broadcast news, frequency lists and DX stories.






Thanks to David Gleason's work, I always have several of my favorite classics downloaded to my I-Pad's bookshelf for offline reading. With hundreds of recent updates this spring, there appears to be a lifetime of vintage reading now available!




As a builder of vintage-style radios, particularly transmitters, I can often find new inspiration from the magazines particularly devoted to ham radio. If your workshop library is lacking in vintage reference material, you need look no further than this site for a vast source of building inspiration....transmitters of all description along with receivers from crystal tuners to complex multi-tube designs.



So many of these early publications were the brainchild of Hugo Gernsback, a prolific writer and editor of both technical and science fiction magazines but sometimes blurring the boundaries of each! I suspect that his wide variety of radio publications had some significant role in the way radio so quickly transformed the world.
Even in the 50's, long after the 'golden years' of radio, it was not uncommon to still see radio antennas on most houses, at least in my neighbourhood!







If you haven't visited this wonderful resource yet, I'm sure you will be amazed at what you find.
Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

The slow adjustment resistor

In my last post regarding the SWR on my MFJ 1788 mag loop I was suggesting that I wanted to get my SWR below 1.6 and I did get it too 1.4. The reason I want as low SWR as possible is I have better  band width before I have to retune the loop. One reader of my blog Paul VA3ZC also lives in a condo and has an MFJ mag loop as well. He gave me some great great suggestions, one being to go into the loop's control box
(the box used in the shack to tune the loop) and by adjust a certain resistor I could slow the  tuning down and maybe fine tune the loop to a lower SWR.  He also suggested reshaping the coupling loop that is inside the mag loop. I decided to give the resistor a go first. It's much easier for me to open the control box and adjust a variable resistor than to open the loop up and start adjusting the coupling loop and put the loop cover on and give it a go.

What was left of battery holders

I was able to adjust the resistor to the point were the tuning light was flashing about 3-4 times per second as Paul had informed me that his loop had been adjusted to. Once done I gave the tuning process a go and it turned out the lowest SWR I could get was 1.7! I tried moving the loop all over the balcony and it made no difference. I found at a slower speed the SWR would jump very fast from 2.0 to 1.7 and bang back up beyond 1.7. It's not that Pauls suggestion was incorrect but these loops are very funny bunnies. I did take a picture of where the variable resistor was before I began the adventure and I decided to put it back to that adjustment. Low and behold I was back to the 1. 4 SWR. If I want  my next adventure will be to adjust the coupling loop inside the antenna housing BUT I just don't want to get myself in a "I wish I just had let things well enough alone" situation. I did find when I opened up the mag loop control box the battery hold turned very brittle and was falling to peaces as I handled it. The control box can run off batteries if need be but not this one until I replace the holders. With the Christmas season on us I will once again have to ask my readers to hold on with regards to the Sun SDR2 Pro SDR radio update.
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].