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As the owner of a Kenwood TM-D710 I was interested to see that Anastasios, SV8YM, has developed a mod to fix the problem of the failing IF filters which causes these radios to go deaf after a couple of years. As explained in admirable detail in his original article describing the problem, it is caused by electromigration due to the fact that Kenwood omitted DC blocking capacitors on the input and output of the ceramic filters. This issue affects the TS2000 as well.

As you can see from Anastasios’ excellent photographs, the mod involves cutting some tiny circuit board tracks, bridging between pairs of them with wire, then soldering 0.1uF SMD capacitors between the bridge and the filter input. The TM-D710 has two receivers, each with two filters (one for wide FM and one for narrow FM) each of which has both an input and an output that needs to be treated. So that is 16 tracks that need to be cut and 8 tiny capacitors inserted. I’m afraid working with these tiny components is beyond me, which is a shame as it is now, while my Kenwood is still only a few months old, that it needs to be treated.

Thanks to SV8YM for sharing the details of the modification.

Version 2.0 of Xastir, the open source APRS client, has just been released. The new version now supports OpenStreetMap mapping, the same as is used by APRSISCE. I was interested to see that the project web page claims it runs on Linux/FreeBSD/Solaris/MacOSX/Windows so I thought I would try it out on my shack PC which runs Windows. I was puzzled that there was only one download file instead of different versions for each platform, but thought that perhaps they had recoded it as a Java application. I downloaded the .tar.gz file. opened it in BitZipper and found a load of source code files but no .EXE.

There is a file called readme.W32 which contains a lengthy and complex explanation of how to install the program under Windows which involves compiling it yourself using free software development tools. I seem to recall trying this once with an earlier version and failing. Most other developers of popular free software ham radio apps, such as Fldigi, WSJT and WSPR, now produce ready to run compiled versions for Linux, Windows and any other platform their program runs on. Why can’t Xastir’s developers do this? Most APRS enthusiasts don’t possess a PhD in computing so it’s unrealistic to expect them to do it.

Last week at the Waverley Amateur Radio Society monthly meeting there was a fascinating and well-prepared talk from Justin Lavery VK2CU on the history of the Heathkit company.

The scene at the front of the clubroom was not unlike this great shot from the website of Fred W1SKU.

Heathkit equipment on display at W1SKU

Only there were more pieces of equipment on display! Justin’s clearly been collecting for a while, specialising in valve gear and the SB series. He had a stash of catalogues dating back to the early 1960s which evoked memories for many of us there old enough for Heathkit – even on the other side of the Pacific Ocean – to have been a radio icon.

Justin filled in the deep history of the company, with its kit airplane beginnings through to its heyday when it actually made economic sense to build your own colour TV!

He also managed to evoke the history of the time – which is some achievement for someone who I don’t think was actually alive for most of it!

MAKE magazine beautifully evokes the times and the anticipation – those long painful delicious moments between posting the order and the kit arriving.

Heathkit times (MAKE Online)

I was especially interested in observations about how the fortunes of the company were in synch with a strong tradition of making it yourself – which seems to be a core part of both the US and Australia. We both have frontier experiences still in our recent folk memory.

I wonder what Heathkit would make of the kit market today if they were still around. They certainly set a benchmark. And they certainly sold a lot of kits over the years.

So it was an interesting coincidence for me at least that on the same day as I’m thinking about Heathkit and how I used to long to own an HR-10 and a DX-60, I received my Genesis G59 Mk2 SDR transceiver kit.

The Genesis G59 is a very exciting sounding project. I believe I’ll have a pretty impressive SDR transceiver once it’s complete.

While GenesisRadio is more cottage industry in scale than Heath – who grew so much they opened a factory in the UK – the quality is there where it counts. Part of the decision to take the plunge was an estimation of the support both from Nick Hacko VK2DX and the online community of builders on the Yahoogroup.

One step in phase 1 building the G59 SDR kit

The then and now comparison shows how much kit building has changed. Kits now can be delivered across the world in days. Speedy support from a global network of enthusiasts is available via email. Documentation is able to be kept up-to-date and builders alerted to important developments. And most amazing, of course, the firmware can easily be updated and improved.

The key to the success of all of this is the social glue of the builders online. That’s another reason not to delay the build and to glean maximum advantage of the communal energy available there.

The Genesis documentation is clear with excellent photos. Not the component by component style of Heathkit, but totally adequate.

So far I’ve completed phase 1 successfully (the power supply) and am in the middle of the second phase (the microcontroller circuit). I’m taking it slowly and really enjoying those moments at the end of the night when I can get to it. That lateness is the one reason I’m taking it slow. The other is – I really enjoy this part!

Welcome to the new home of The K3NG Report.  I’m still getting things in order, most noticeably the blogroll.  I’m going to try to get all the blogs from the Blogger blogroll that are not covered at AmateurRadio.com in as RSS feeds.  Unfortunately WordPress doesn’t seem to have a good blogroll widget like Blogger, but it’s a small price to pay.

In an earlier post, I described my K9AY loop system.  QRX for an update on the outdoor portion.  But, after returning from a short and much-needed vacation at the beach yesterday afternoon, I whipped-up this little guy:

One of the big problems I have living in the city is overload from broadcast stations in the AM band.  (This is especially true in the heavily-populated, full-of-hot-air DC area—Ed.)  But, I digress.  I also wanted to protect the preamp and receiver when I was transmitting on the higher bands into nearby antennas.  So, some sort of filtering was in order.

I contemplated a number of topologies.  But, the W3LPL filters were a good choice because they’re cheap and very good.  A good reference on what I did is the NCJ article by K3NA and W2VJN about the VP6DX receiving antenna system.  The Ducie Island system is considerably more complex than mine.  But, they had more stringent requirements, more land for Beverages, and more money than I do.

Following the K3NA/W2VJN/W3LPL topology, I constructed a little diplexer filter for 160 and 80 meters that splits my K9AY to two receiver ports.  This splitter is the first thing after the K9AY coax passes through the station ground bulkhead, requiring a preamp on each port.  Since I don’t have a TX antenna for 160 yet, that port will go to the SoftRock-160.

I’ve only tested the 80-meter portion (since I didn’t get the 160 portion done until this morning before work).  But, it works like a champ and there is no overload from broadcast stations.  Although there are some curious mixes coming from some of the big AM stations in the area that seem to be external to the receiver (this has been confirmed by N3OX—pretty amazing stuff); but, that might deserve its own post at a later date.

Yep, it is confirmed now for sure. Compulsive Antenna Disorder has haunted me since I was first licensed and ran a coax fed 80 meter dipole on multiple bands without a tuner.  The first time the symptoms were noticed by my family and friends was when I got a couple OO tickets for out of band harmonics. Hmmmm… what’s up with that? So a bit of reading and the antenna tweaking began and that’s when it all started.

Soon thereafter I tried to load up a nifty pin from my Junior Prom Boutonnière that reminded me of a triple stacked halo for 1296 Mc (MHz for the newer ones amongst us).  Then it was the handheld yagis for 432 Mc that we used with some military surplus gear that used dynamos so we could chase tornadoes. (We thought if it bounced off the moon, it should bounce off of a tornado!) The saucer sled that became a parabolic for listening to satellite telemetry and on it goes… Compulsive Antenna Disorder has had a firm grip on me for some time now.

Am I dreaming? Thanks wiki images!

As a QRP operator, I am always looking for more antenna power. I know that somewhere out there simply MUST be a silver bullet, that magic QRM and pileup busting antenna that makes my 2 watts output sound like a full gallon.

I can say one thing for sure, I know a lot of non-silver bullet antennas, as I have a box full of them.

But they still make a few QSO’s at times and I’m having fun along with a bit of frustration and disappointment as I deal with my CAD affliction.

I’m told that much like telegraph key collectivitis there is no known cure or relief. I share in your grief brothers and sisters…

72,

Kelly K4UPG PB #173

Over the last few days a North American ham has been operating a beacon at the top end of the 30m band on the frequency that has been used for many years for HF APRS. At times this has made HF APRS operation impossible. After some difficulty, due to the fact that the beacon operator’s contact information was incorrect, someone managed to get in touch with him to point out the problems he was causing and ask politely if he would move the beacon. This is part of the reply that was received, copied verbatim from an APRS mailing list:

“Last week I  moved the beacon when  some other hams we’re bitching at me  about ‘their’  all important!!!   ham activity……   PSK,  RTTY   what ever!!! . 

I move AGAIN then another cry baby bunch CRIES about ‘THEIR’  ALL IMPORTANT    activities  like weak signal CW QRRS CW  whatever!

We have to SHARE the frequencies   I will think about the  QSY  …..  if I get Bitching from so other ham ‘group’ like the DX cluster folks who are  ‘DXing’  fish in a BARREL for some  ALL IMPORTANT  ‘certificate’     What am I to do???  I am an experimenter /builder  when do I get to use a frequency????????

WHY is ‘APRS’  more important than MY activity?  I look in the regs and I  see NOTHING about one  ham activity has  priority over another!”

I have left out the individual’s details as I don’t want to start a personal attack that could be counterproductive by leading him to entrench his position. But whatever happened to good manners, politeness and consideration for one’s fellow amateur? When, as a young teenager, I first began listening on the amateur bands, I used to be impressed by the politeness and courtesy of the conversations I heard. No longer is amateur radio a gentleman’s hobby.

This OM is quite correct that we have to share the frequencies. It is a common courtesy that if a frequency is in use then you don’t use it, even if you have a net that has been meeting on that frequency every day since Marconi invented the spark transmitter.

But in the digital parts of the bands which can be used for more than conversations between two or more people, checking whether a frequency is in use may involve more than just sending “QRL?” or listening for a couple of minutes. Activities like APRS, packet radio, Winlink and so on are effectively nets that operate 24/7. If you don’t hear anything for a while that may just be because propagation isn’t sending anything your way at the moment.

This is how Chris, G4HYG prepared to select the frequency to use for APRS over PSK. He recently wrote: “Before I released the HF version of APRS Messenger I spent some time checking  various frequencies on the 30m band. I found that the section from the 300 bd APRS frequency to the band edge appeared to be clear. I then started a period of monitoring the band from 10.1494 to 10.150 on a receiver with a digital mode program running with a very slow waterfall to catch anything I heard. This ran for a month from mid January to mid February.” It’s a pity the developer of the ROS digital mode that has caused so much disruption to other established activities could not have been as thorough and considerate in selecting operational frequencies.

To those who will trot out the response that activities like APRS have no more right to use a particular frequency than anything else I would say first of all that some types of activity need a specific frequency where other users can find it. It isn’t a matter of one activity being more important than another. If you had to hunt to find what frequency everyone is using today, some types of worldwide net operation would not be possible. In any case, a frequency that was clear in, say, North America might well be occupied in Europe. Allowing legitimate activities sole use of an established frequency by gentleman’s agreement is the only option. There is still plenty of room for other activities including ad-hoc beacons.

In activities like APRS, many dozens of stations all use the same frequency, making this a very efficient use of bandwidth. If users are driven off these frequencies or prevented from using these modes the result would be even less space left for other activities.

What people who object to this argument really mean is “I don’t have any interest in that mode and I don’t give a fig about those who do.” Is ham radio a fraternity? Yes, we are like a family of brothers who are forever breaking each other’s toys and beating the shit out of one another.