AmateurRadio.com

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

No, I’m not expecting any new radio related ironmongery or a new rig. Especially as this week seems to have cost me a small fortune ( I had to buy a new car but that’s another story). Bust Christmas can give you a little bit extra, time that is.

I’ve only planned on doing 2 things, one is to activate the clubs callsign MX0WRC on Sunday, something that hasn’t been head on the air for a while. After refurbishing the shack the temporary antenna came down in the strong winds we regularly get so a Delta Loop will be helping us out. The plan is to show a few of the more novice operator how to use the clubs kit in the warmth. So if you hear a feint CQ from far off Cumbria then please call back. You may make a novice’s day.

The other little job will be to give away a few points in the RSGB VHF Christmas Cumulative contest. I’ve long lamented about the poor VHF signals that make it into St Bees but with a fair breeze I should work a few stations further afield than GD land (about 40 miles across the Irish sea). I’ll probably do it from the house so the QSO’s will be less than 10 but hey its only a bit of fun.

So If I don’t hear you or work you on Sunday then I hope to try again between 26th December and the 29th December for some armchair operating. Tea and biscuits at the ready!

Alex Hill, G7KSE, is a regular contributor to AmateurRadio.com and writes from Cumbria, UK. Contact him at [email protected].

The Model One has been a huge success. But in many ways it is a daring retro design judging from all the features that are missing in this radio. I am thinking of features such as a customizable equalizer, a digital display, and memory presets. It just has a plain old analog tuning dial for FM and AM.

The radio could as far as I can tell just as well have been made in the 70’s except for some of the IC’s which are used. Actually it is easy to see the similarity with the even older KLH Model 18 from the 60’s, and yes – Henry Kloss played a role in both radio designs. But that makes for easy repairs, such as a seemingly common fault in the FM tuning capacitor, which over time may develop contact problems.

The radio is in many respects exceptionally well made. The tuning dial has a quality vernier drive. The audio section is well built with a powerful amplifier, a strong magnet for the loudspeaker, and a bass port design for the wooden cabinet. All are factors which contribute to its reputation for good audio. If one can trust measurements on the web, it has been equalized for enhanced bass and treble with the mid’s some 6 dB down. These are well-known tricks for getting a warm and crisp sound with universal appeal. Internally the tuner section, which is built around the TEA5711T chip, is well shielded for frequency stability as seen in image 2.

One weakness which manifested itself after only 3-4 years in this particular radio is that it became hard to tune, scratchy, and unstable on FM due to intermittent contacts in the tuning capacitor. According to the TEA5711T datasheet it is a varicon which for AM has 140/82 pF, for FM 2 x 20 pF, and for trimmers 4 x 8 pF. This particular unit had a Mitsumi varicon. Some say, when this fault occurs, that the varicon must be replaced and others say it can be cleaned. Who do you think I sided with?

Disassembling the radio is quite straightforward if you are used to this kind of work. The tuner is enclosed in shielding on both sides of the PCB. The shields can carefully be desoldered as shown in image 3. That exposes the varicon, and its plastic casing can be lifted as shown in the last image.

I sprayed it with contact spray and the radio came back to life. The only problem was that the tuning on FM had shifted so that a station on 100 MHz now appeared on 107 MHz. A little detective work around the circuit showed which trimmer that was for the FM oscillator and which one that was for the FM RF circuit (marked O and R in image 2). Since the oscillator trimmer was set for its maximum capacitance with the plates covering each other, it was easy to reduce the value and get the FM dial back to normal again, and then to peak the RF trimmer.

It got me wondering though to see that it had been necessary in the first place to have the oscillator trimmer set at its maximum value. It was just as if the tuning capacitor never had had its full value, even in the factory, and that it finally got it after my cleaning.

Sverre Holm, LA3ZA, is a regular contributor to AmateurRadio.com and writes from Norway. Contact him at [email protected].

As we move past the peak of this current solar cycle it seems that we are enjoying some of the best conditions on the high bands in several years. However, there does seem to be a sense of urgency to enjoy 10 meter DX since these conditions will likely last a few weeks rather than a year or two as in past cycles. I remember when I received my Novice license in 1989 that 10 meters was so busy you could hardly find a spot to call CQ in the Novice band, 28.300 - 28.500.

Since the flux has been in the 160 -170 range lately, last week's 10 meter contest was full of activity. It was a great opportunity for me to increase my QRP DXCC count which was at 160 entities worked going into the weekend. The bottom line, with the exception of V55V on SSB, I was able to work everyone I chased. It was harder work that I thought it would be, which is a testament to how busy the band was.

So with the band hopping, I fired up the KX3 and went hunting. I was able to work TK5EP, 4O3A, OX3XR on CW and ZS1TMJ on SSB. It was Saturday morning when I made these QSO's, so it was still early in the contest, I'm sure on Sunday, these stations would have been a little easier to work. I picked up four new counters on 10m and threw in FG5FR on 15m to get my QRP DXCC to 165. It was a fun weekend and it's good to hear some much activity on 10m.

So, go have a look at 10 meters, better yet, call CQ. You mght be surprised who comes back.
Mike Crownover, AD5A, is a regular contributor to AmateurRadio.com and writes from Texas, USA. Contact him at [email protected].

AmateurLogic.TV Episode 61 is now available for download.

It’s the AmateurLogic Christmas Spectacular. Join the crew and special guest for a festive holiday event.

Peter hacks his Degen SW Receiver. Tommy puts the Arduino on TV. George trudges on in his effort to use the Raspberry Pi as an Echolink node. And a hilarious look at the 2013 ALTV Holiday Gift Guide.

A 1:13:08 AmateurLogic celebration of the season and other good stuff.

Download

View in web browser: 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].

It seems to have evolved that the time I think of doing some DSTAR operating is when I’m out in the garden on a Sunday morning doing whatever chores are possible or needed (possible relates to the winter weather!). This morning, I popped out to clean out the henhouse for the girls and booted up the Raspberry Pi and DVAP.  Happily it came up straightaway, which isn’t always the case and I ventured out.

As usual, there were some nice QSOs to be had; Tom AA8RT in Dallas, talking about the winter storm they’d had last week, Ian VK6SKY who, at the other end of the temperature scale was having a really hot summer with over 40C. Another really nice QSO was with John LA2QAA on Frei Island.

John is kind enough to read this blog (hello John!) and it was interesting to talk to him about some of his satellite experiences, as a control station for Oscar-7 as well as how difficult it is to use the SO-50 satellite from his high latitude.

After I’d finished the nice QSO with John, it just came onto rain, so I finished off freshening the henhouse and ventured in.

I took the opportunity to update the G4KLX ircDDBGateway and DVAPNode software on my Raspberry Pi to the latest versions (20131001 and 20130904 respectively) as it was a little while since I’d done that.

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

Series Six Episode Twenty-Five of the ICQ Amateur / Ham Radio Podcast has been released. The latest news and Martin reviews which digital mode to use.

• Summits on the Air revitalised by involvement from "Down Under"
• Comet ISON disintegrates, no lives!
• GB3EB new Eastbourne 2m VHF repeater
• Kerry Amateur Radio Group repeater move
• New VK6RIO beacon on 144.950 MHz to beam at South Africa
• Latvian Special Prefix
• December is Ham Radio YOTA month!
• VHF Communications magazine closes
• Radio microphones changes in NZ
• Vandalism at Australian amateur radio club
• ARRL granted use of W100AW for League’s centennial
• RSGB IET Lectures available
• Could you write software for IOTA?

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