Tag Archives: lab work

The Future of Amateur Radio

children are the futureGoing through Yahoo group posts this morning I came across something on the Ham Instructors group that caught my attention, a discussion on the demographics of new hams and whether or not the focus for recruiting should continue to be centered on the idea that children are the future of ham radio.

Many hams, maybe even most hams, share a basic story line. They got interested in radio as a pre-teen or teen, usually exposed to radio by family, friends, or social event. Most drift away from radio as they go through various stages of life when they are swamped with the normal stuff life tends to throw at us all, school, marriage, having kids, career, the usual. Later on as things settle down radio creeps back into their life. Some manage to get licensed during that early exposure, some end up waiting several decades before getting a ticket.

In my opinion, providing the young an opportunity to catch the radio bug is the best bet. They may never actually get an amateur radio license and their attention may turn down many different paths. But the likelyhood of that exposure being beneficial to the amateur radio community down the road in some other form is immense. They would at least have some understanding and appreciation for amateur radio and its benefits to the community at large.

While I think the positions presented in the Yahoo group and associated blog posts K0NR and KB6NU are certainly worth looking into in greater depth, I think there is a more pressing matter that may affect the future of amateur radio.

Why is amateur radio experiencing a huge upswing? Basic statistics show the upswing began in 2008 shortly after the FCC dropped the code requirement for all amateur licenses. Wheather or not that decision was good for the service I will leave alone for now.

My ham path followed a derivation the one I described above. I got interested in radio as a teen back in the 80s but didn’t get my license until I was 46, only in part because of the code requirement. My reasons for finally getting my license were centered on personal emergency preparedness, serving the community, and to have fun experimenting and building RF electronics.

As a Volunteer Examiner I participate in license exam sessions and it seems that the predominant reasons for taking the license exams generally follow along with the age ranges:

Retirees & Pre-retirees are either upgrading an existing  license, had a licence but it expired and are getting back into the hobby, or always wanted to but hadn’t gotten around to it till now. Or you could say, the story we are so familiar with.

20s & 30s seem to be engineering students or engineers, Makers who have projects that require a license, or preppers.

Teens and under seem to either be in a social program like a school club or scouting. A few come from dedicated ham families.

Pretty much what you might expect, but there are a couple that might have an effect on the ham future landscape. Two categories that could pose concern.

I’ll start with Makers. By in large these are folks who embody the early spirit of amateur radio, they like to build stuff. While they bring to the table that early spirit of radio, how many of them participate in the radio community? Are they here because of one project they might need to be licensed for, or are they going to keep renewing their license and play radio alongside other Maker pursuits? Either way, I am glad they are here now. They do indeed advance the science and art of radio. Down the road however the passing interest MakerHam may drop the Ham part altogether.

The other group is of particular interest, preppers. My hats off to them if they actually get licensed, many more don’t. It is common practice for prepper groups to buy cheap Chinese ham-band radios and use them regularly on FRS/GMRS radio frequencies which is illegal, at least when it is not an emergency, but they are much less likely to get busted for that than using amateur frequencies without a callsign.

One thing to consider is the term prepper. There is a massive range of people who consider themselves preppers that covers the entire spectrum from keeping some extra food and water along with a flashlight, first aid kit, and blanket, something we all should have at a minimum by the way, to the massive underground hords and compounds guarded by paramilitary groups.

Another consideration is, do they further the science and art? Do they participate? If so, welcome aboard.

I mention these two groups of people not to place judgement, but rather to ask if they are a part of the ham community. The reason for asking is, what happens if they don’t renew their licenses? There was concern that the ham community was dwindling away, leading to a loss of tribal knowledge. What happens when non-invested license holders don’t see the benefit of keeping an unused license? Or just forget about it?

Amateure radio has been experiencing an unprecidented growth spurt over the last 8 years. We still have two years to go before the early no-code era hams begin to cycle for renewal. I would imagine the first few years after the start of the second ten-year cycle won’t see much of an effect either way, but what happens in 2020? Will we start to see a roll-off?

In general, we seem to be more focused on recruiting rather than retention. Back in the day, the code requirement acted as a filter. People with only a casual interest in amateur radio were less likely to pursue it. While it worked fairly well as such, it also filtered out people interested in radio, just not cw. Now we have no filter at all. The only impediment to getting licensed is $15 and some time studying the relatively small question pool. You can be a Technician class licensee in short order.

In life, most things are more valuable when you have to pay for them, monetarily or by blood, sweat, and tears. Personal commitment to seeing it through establishes the value. This basic principle would indicate that removal of the code requirement and as some would say, lowering the bar on the knowledge test, the sweat equity has been removed or at least lessened thereby the value, at least the perceived value for the licensee.

So now we have several issues to contend with; keeping the number of licensees up, ensuring that they keep their licenses renewed, and keeping some level of commitment to the hobby and community at large.

Frankly, I have no idea how to accomplish any of these. I don’t think we have enough data. Too many things have changed in the hobby in the last decade and we still don’t have any results from what I think may be the most impacting factor, the dropping of the code requirement. In all honesty, I doubt if we can even begin to answer these questions until 2020 and the effects can be quantified.

In the meantime, we should continue to do as we have always done, inspire and encourage the youth, at any age. Encourage fellowship among the community, Elmer whenever possible, maintain the highest personal standards, and reach out and engage the radio community and the general community at large.

The Amateur Radio preservation mantra,
“Engage, Inspire, Encourage, Educate, Participate”


Solder-less Progress

Some good stuff got done this week even though I didn’t melt much solder.

I had an amateur radio testing session on Saturday. It was a busy day with lots of new hams passing there Technician, some going on to pass the General exam, and even an Extra! We also had several upgrades to General and Extra.

For me the session was also a good learning experience as a VE because I had the opportunity to get some training in another job with the group.

We basically have three jobs split among the VEs present at any given session; two administrative jobs, and a panel of test examiners.  I have been participating as an examiner for the last several months. Today I received some training for the administrative side of things.

I have been putting off the testing on the Beach 40 until I get the last few details finished on the audio and RF amps as well as the LP filter. This week I am playing beginning of the month catch-up with the day job so time is short.

Also tied to everything else is the change over from Windows to Linux. I have deleted the Win partition on the laptop and am now running full on Linux. I am loosing two programs I liked but just couldn’t get them to work with Linux native or emulated and I don’t want to run virtual machines. I still have all of the data, and I do have a Windows 7 laptop in the shop I basically only use for the web browser.

The programs I am loosing are Quicken and Business Plan Pro. BPP will just go away. I exported all of the business plans I have put together over the last decade to .doc files which I can access through OpenOffice. I can use the previous plans to build new ones as needed in document formats.

Quicken is the one giving me headaches. Supposedly you can export the data to a file for import to Skrooge. No joy. After several exports and several hours I made the contagious/stupid decision to just go back and reenter all the data for this year.  It sounds a lot worse than it is. I will just do one month at a time and by the end of this month I should be all caught up. Not to mention very familiar with the new software.

I have found replacements or versions that will run on Linux or in emulation for all of my radio software an in fact found some new stuff that looks mighty interesting. Big plus here.

Along with the radio specific software, I found gEDA Schematic Editor. WOOT! It took a little getting used to the interface and component placement, but I like the results a lot. I have been redrawing the schematics I originally did on schematics.com for the Beach 40 and think they look much better. I will be posting them soon to the build page. A good thing too because there are some errors on those schematics. Ooops!

One last update before I go, I was working on test prep for my commercial radio license a while ago but got sidetracked by all of the build projects and the day job. One of my goals for second/third quarter is to take my commercial radio exams, at least two of the three anyway, and get my commercial license. So I will be committing some of my limited time to that endevor over the next few weeks. The build will continue, I still hope to have the Beach 40 up by Field Day, but I need to budget more time to the Day Job/Future Day Job.

Anyway, I have 0.5TB of files syncing with Google Drive and a pile of accounting stuff that needs to find a new home in Skrooge so that’s it for today.

Until next time, 73,

Back to the radio

KK6GXG-MakingWavesTo keep domestic peace I have not been building on the Beach 40 non-stop as I might otherwise do and there is a side benefit… By taking some time away from the build I can clear out the cobwebs and refocus on the greater project to check my thinking and my work.

I still need to do testing on a few of the sections. However I have all but two sections assembled with only minor followups. I need to figure out the value of the common emitter voltage limiting resistor on the Audio Amp and I need to wined and connect the two bifilar toroids in the RF Amp.

T_R Switch
Not a literal schematic, just a rough idea

The last two sections to build are the Low Pass Filter and the T/R Switching sections. The bit that I have been burning cycles on is the T/R Switch. I want to do something that consumes the least power overall at-rest, something basic and bulletproof.

My current thinking on the T/R Switching is a pair of relays, one NO and one NC. RX on the NC and TX on the NO. This way everything is normally in the at-rest state and I only need to run one power lead from the TX momentary switch to both power leads on the relays. Since I don’t have the relays in stock I will need to go get a pair. Sounds like a trip to HSC. 🙂

Once I have the relays I will draw up a new schematic for this section and get it posted on the project page.

While not working on the Beach 40, I did do some radio stuff. I picked up some parts for stock from Jameco one day, a bag of varactor diodes, then two days later went back to pick up voltage regulators, a bag each of 5, 9, and 12 volts.

The XYL went with me to a local Radio Shack that is closing down. We picked up a bunch of zener diodes, a pair of bridge rectifiers, and some mechanical connections at 80% off. There wasn’t much left to pick through. I also found a pair of NO SPST relays which got me thinking more about the previously mentioned T/R switching circuit.

I also ordered a few bags of various op amp transistors that are frequently used in radio circuits. Purely a stock order, and I’m pleased to say the parts bins are slowly filling up and I am getting to the point I think I could actually build my next radio without going out and buying any parts. This is a good thing and I’m fairly certain my wife will agree.
Sneak Peak: I’m thinking about a Beach 20…

Also radio, not Beach 40, the beginnings of research on VFOs. I have been looking at a lot of material on VFOs without finding what I am looking for. I want something small physically, low power consumption, as close to all discrete components as possible, all readily available parts, stable, and a wide tuning range. A tall order I think.

First pencil sketch, next into the lab book and beyond

A first design only slightly out of specifications is this one I worked up from a test circuit diagram from N6QWs VVC page and the NE/SA602 spec sheet. It will be my VXO-X01 build. 😉

An Experiments page has been set up to keep a log of these kinds of long-term projects. I haven’t created the page for the VFO research yet but that will be up shortly after I update the Beach 40 build page.

One other non-radio, well mostly, is the slow planned migration to Linux. I have been wanting to this for a long time but the last time I tried it wasn’t so well planned. This time I am running both Linux (Ubuntu) and Windows (8.0) side-by-side rather than one virtual. It will be a long protracted process this time but it should result in a much better transition.

That’s it for now. Trying to keep the smoke inside the parts where it belongs until next time,


The AADE L/C Meter IIB

If you don’t work with RF electronics the need for an L/C meter may not be readily apparent. If you work with RF, you have likely found capacitors and inductors in the junk pile and played hobb trying to figure out the value, unless of course they were marked.

My first homebrew toroid inductor. Aint she purdy?
My first homebrew toroid inductor. Aint she purdy?

If you wind your own inductors or make your own capacitors the need for an L/C meter is a no-brainer. I bought a cheap Chinese manufactured meter and it was no bueno. No redeeming qualities what-so-ever.

Within the Amateure Radio world AADE (Almost All Digital Electronics)  and the L/C Meter IIB has earned an almost legendary reputation for being just the piece of equipment the homebrew ameture needs.

20150518_173544Being a homebrew ameture and a recycler of electronic components, I decided to buy the L/C Meter IIB kit and build it. The kit itself is very straight forward. Assembly is well documented and easy to follow.

I have been generating a lot of solder smoke lately so I may have an advantage here in assembly speed but I went from shipping box to functioning test equipment in about 4 hours.

20150518_194352Starting with full parts inventory I went right into construction. The parts list is only one sheet and it is very detailed. After checking in all of the parts and tagging them to the parts sheet I fired up the soldering iron  and started melting metal. Filling the printed circuit board didn’t take long at all.

Th20150518_212344e only hiccough was technician error. I got all of the components soldered in, mounted the board in the back of the case, mounted the LCD, and plugged in the battery. When I turned on the power switch I got nothing. I knew from reading the instructions fancy that that a common oversight is that the contrast pot should be turned fully clockwise. When I went to check the pot I noticed something missing, I forgot to install the IC’s in the sockets. Doh!

A great product that supports a US, family owned and operated business AADE L/C Meter IIB

After installing the IC’s I checked the pot and Voilà! A working L/C meter.

At $100 a kit that looks as simple as this one does you may be tempted to buy a cheaper factory assembled meter. I would strongly advise against it. A comparable factory manufactured meter will set you back at least twice what the L/C Meter IIB will, probably more.

LC meter
Save yourself the time, trouble, and expense of having to return this piece of junk, don’t buy it in the first place

I purchased a cheap meter for $38, paid $6 for shipping and another $8 to return it. Sure, it looks nice but it is complete garbage.

And if you need something else to push you over the fence on this purchasing decision, buying from AADE supports a family run US business that takes pride in the work they do. Now that’s a bargain at any price.

Solder smoke is filling the air as I continue work on the 40 meter Beach 40 DSB transceiver so check the build page for updates. I will be making an update tomorrow!

73 for now,

New-To-Me Signal Generator

120 kc (kHz) to 200 mc (MHz)
120 kc (kHz) to 200 mc (MHz)

On Saturday I picked up a few things at the De Anza Electronics Flea Market. The most impressive acquisition would be the Lafayette Signal Generator for $20.

I have been needing one and I was dreading the prospect of having to build one and having a tough time without the right tools for calibrating it, so this was a great find and a steal of a value, though I didn’t know it for sure until today.

One thing I have learned about buying used electrical/electronic equipment, particularly in at a flea market, is that you have to take your time and open it up, get documentation, inspect and clean the equipment before attempting to use it, or plug it in for that matter.

20150414_075130 Sunday was opening day. I noticed right away that I would need to replace the power cord grommet as it was in two pieces. I didn’t actually get to anything else until today.

Today I inspected all of the wiring and components, looked for hot spots and anything that would indicate an over heat. Having found nothing of the sort I moved on to cleaning, which there was surprisingly little to do. I made sure the tubes were cleaned and had no fingerprints on them. Now that I have a piece of tube equipment I will need to get a tube tester. 😉

With the cleaning done it was time for the plug-in and smoke tests. No pops and and no smoke! I let everything warm up and burn in for a good twenty minutes before starting any tests.

Testing with the oscilloscope began with the AF (audio frequency) side of the generator. After the twenty minute warm up period the “approximately 400 cycles” audio tone as specified in the manual turned out to be stable at 388 cycles (Hertz). I can work with that.

“kc” is kilocycles. The term is essentially the same as the more familiar kilohertz along with “mc” megacycles being the same as megahertz. The change over in terminology occurred slowly from the mid 70s to the mid 80s. Many hams still use kc and mc. I use them interchangeably depending what I am referencing or who I’m talking with. This piece of equipment has frequency labeled on the dial as kc and mc.

20150417_152319Moving on… The generator did its first diagnostics job with a portable amplifier I have had for a very long time (the one on the right). I clipped on the amp to the audio out and it turn out the volume control on the amp is trashed from banging around in my tool bags for a couple of decades so I will need to replace the potentiometer in that this weekend.

I then moved over to the RF (radio frequency) side of the generator and clipped on the oscilloscope. The RF side is divided into 5 switchable bands. I checked each band by referencing the frequency on the dial with the frequency on the O-scope. All five bands checked out very closely to the dial. A little lead or lag here-and-there, but overall pretty close for this equipment and its age which I’m guessing is about as old as me (made in the mid/late 60s).

20150417_152206The frequency counter I purchased last year has been giving me problems. New equipment, cheap (figuratively and cost), and no manual. With the help of the new sig gen and the oscilloscope I managed to fix a couple of minor problems and figure out the modes on the counter in the process. Looks like the electronics bench is finally coming together.

Now that I can check the receivers I build I can also check the transmitters I plan on building. I can also check portions of the radios as the construction moves forward. I plan on building more of my own test equipment but it’s nice to have a reference point or two to calibrate off of.

I also did some diagnostics on the 40 meter direct conversion receiver project and updated the project page… some very interesting results, you should take a look. 🙂

A productive day I think.


Fresh Prespective

Over the last few days I have been working on a direct conversion receiver project I found in the book Experimental Methods of RF Design last month. I had been planning and even started a very similar design back in February. I was having problems with that project so I picked up the EMRFD book to help figure out what the issue was.

EMRFD-40m-ReceiverThere in the first chapter was this design and I decided to scrap the other project and started working on this one.  It wasn’t like “oooo, a new shiney…” because they are very similar designs and the goal was to build a direct conversion receiver for 40 meters, not specifically that receiver.

Now that I have finished unnecessarily defending my position on hitting the reset button on the project, we can continue.

This time I decided to go with the “ugly” method of prototyping. I was not aware of the induction issues with the plastic pinboards or the other problems that can arise with high-speed or precision circuits. I had seen a few things on ugly construction and comments on its superiority over the plastic breadboards, along with other similar prototyping methods like “Manhattan.”

Since I had never done ugly before I was a bit nervous about it. I have used perfboard successfully on other projects and while perfboard does not have the same negatives as pinboards, it doesn’t have a ground plane ether. This can be problematic in RF circuits.

Any hoo. Yesterday I finished soldering the board and started mounting stuff. The project is screaming along and I have been pulling back regularly to make sure I don’t rush to finish. I have been going back an checking the new additions for physical problems, shorts, cold soldering, and the like. So far things have gone nicely.

20150401_193337This morning I sat down and looked at the partially mounted project box and some things crossed my mind. If I only put an antenna port on the back, instead of including a power port, I could actually have an internal battery pack. I could even add the power port and include a charging circuit for the internal battery…

I nixed this idea on this build because I intended to use a battery pack / solar charger that I already have so the power possibilities will be saved for later.

I do plan on adding a transmitter to this case. This brought my attention to the front panel. I am installing a power switch and headphone jack for the receiver, but I would need a jack for the cw key and a TX/RX switch. I could fit both of these components in the front panel integrated with the receiver parts without a problem. I could even install them now to prepare for the inevitable. I even have the parts in stock.

What I didn’t think about last night was the tuning of the transmitter. I don’t have the room for the tuning components on the front panel. I don’t know if I could modify this oscillator/mixer to work in conjunction with a transmitter thus converting the whole thing into a transceiver. I will have to get back to the book and read on.

In all honesty there are a couple of other things too. I would want a beat oscillator which would need a momentary switch and some other logistical elements to think about as well.

I spent a lot of thought on keeping this board small. I didn’t want to crowd things too much, but I wanted a small planform. I got what I wanted and I learned a few things about experimental design.

Planning ahead is not just about where the rest of this circuit is going. It includes thinking about the likely evolution of the project. Would I convert this project to a transceiver? Probably not. I would more likely build a new project ether from a different design already established, or take a lot of time and build modular circuit clusters testing them as individual units and working out the logistics of placement, interfaces, and housing configurations as the project developed.

I am actually surprised at how much I have learned from building this little DC RX, and I’m not even finished with it yet!