The Dummyloads

Where ham brains come to fry

Where ham brains come to fry

Steve Parks

Power!

initial layout and super glue mess

Now that the board is sized its time to melt some solder.  I’m not sure what the real first step is supposed to be.  I’ve heard Eric Guth on the QSO Today podcast talk to a number of builders and answers vary from the audio amp to the Local Oscillator.  I decided to start with getting power to the chips.  Once I had that figured out I’d have a better idea of where the local oscillator would go on the board.  I also decided to add a couple of steps to the power input.  One is a reverse polarity protecting diode and the second was a 5V regulator.  Since I don’t have a real 5V power supply, I am likely to power this with a 9V battery.  The NE602 has a max V+ of 8V so I want to make sure that my V+ stays at 5V and not fry anything.

Power stage complete. . . almost

You will see on the board I’ve laid out and superglued the 8 pin DIP sockets as well as the initial pads for the power rail.  Lessons learned from this experience.  Don’t put superglue on the pad then try to place it on the board.  Put the superglue on the board and then set the pad on the glue.  If you don’t you will smear superglue on your board as you can see in my picture above.  The other lesson I learned was to be a little more thoughtful on where you run the wire from one side of the board to the other.  I think I would run it a little closer to the chips so that the Local oscillator could have a little shorter leads over the power wire to the NE602.

If you look closely at my picture and study the schematic from the initial post, you will note that I’ve wired something incorrectly.  It can be easily seen in this photo (left).  Can you spot it?  Leave a comment below when you find it.

The build has begun. . . More to come!

 

Prepping Copper

8 pin DIP socket soldered to the MePads

Now that I know how the layout is going to run its time to start planning how much copper will be needed for the circuit board.  This will likely be the post where I get the most wrong!  To be clear this is being written as the project is in process, so we will find out together if I set this up wrong. . . but a few weeks from now probably.

The circuit is set up around the two ICs, an NE602 and an LM386.  Planning how these devices will sit on the board and creating enough room for the various components supporting the inputs and outputs will determine the size of copper board needed. The full size 4″x6″ copper board seems like major overkill for this circuit.

4″x6″ copper board is probably too big for our project.

I’ve decided to do the K7QO method of using 8 pin DIP sockets.  While the socket adds ~$.15 to the build, it guarantees that I won’t smoke the IC with my soldering iron being too hot.  I purchased some MePads when building the Regen last year. They went unused as the particular IC I was using was surface mount and didn’t fit.  As you can see in the picture above, these fit the sockets just fine.  I also intend to use the MeSquares for the other shared connection points.  Now that the sockets are on the MePads, its time to lay them on the 4″x6″ sheet and guess how much board I need. 

It seems to me that you would probably only need 1/2 of the board.  Measuring 3 inches across the top and bottom of the board I drew a straight line with a black sharpie.  I carried the line around the back of the board as well.

Copper ready to be drilled for standoff holes

Cutting the board using the AA7EE method resulted in a slightly crooked cut, but ultimately successful separating of the board.

 I also wanted to do the K7QO method of adding stand offs to the board to raise the soldering level up off the table a little.  To keep the holes semi symmetric I measured 3/10ths of an inch from each edge of the board and drilled a hole where the lines intersected.

MePads and MeSquares together

The last step was to scrub the copper with some steel wool and clean it with alcohol.  Then put a couple of coats of matte Krylon on the board.  This should help protect the copper a little and allow me to build on it over a period of weeks without the copper oxidizing.

The project is well underway, the next step should be actually super gluing pads and beginning to solder circuit blocks.

 

 

QRP From the Park

KF5RY (logging) K5JTL (double checking me) and NE5DL (operating)

My favorite radio operating activity is to operate outdoors.  Once a month I try to gather a group of hams together here in the Duncanville, Texas area.  I really have two objectives.  One is to encourage other amateurs to get out and use their gear and the other is to show off our hobby to complete strangers.  We were able to accomplish both objectives in February.

In the picture you see Dave Lear (NE5DL) Justin Long (K5JTL) and Steve  (not pictured is Steve Edmonds (KZ5MSE) as he is taking the pictures).  Steve is visiting Justin and his family and thought it might be fun to see what we consider to be fun.

The forecast was not optimal for radio operation.  Lots of rain!  BUT. . . it looked like we would have a short window for operating.  Justin and I arrived first and set up my buddistick.  I was looking to have a quick put up and take down antenna as the rain was an unknown!

When Dave arrived he opted for a much fuller sized vertical.  Dave uses a custom mount plate with a Wolf River Coil and a 17′ MFJ Whip.  He sets this all on top of an inexpensive tripod mount.  He has 4 radials that are precut to the band and hangs them off of plastic electric fence posts.

NE5DL set ups his radial

 

About 1/2 way through Dave’s set up the skies opened up.  I took down all my gear and ran for the car!  3 minutes later the rain stopped and life was normal again.  Dave never stopped setting up.

Dave was testing a slight variation on his antenna and we had a little trouble getting everything dialed in correctly.  Fortunately between everyone on hand we had enough tools to make it happen.  In the middle of all this a man starts shouting at us.  I turned around to see a pick up truck parked in the middle of a very narrow road.  Outside the truck and approaching us is a very large man in a cowboy hat shouting, “OK. . . You got my attention.  What are y’all doing? ? ? Are you talking to aliens?”

Fortunately Justin Long (K5JTL) came to the rescue on PR duty.  While that was ongoing Dave and I were able to get the antenna finished up and on the air.  We were able to operate for about an hour.  Dave made a couple of contacts while I logged.  The last contact we made was myself (KF5RY) and Don (VE4ESE).

Overall it was a great day.  If you find yourself in Dallas County and are interested in joining us let me know and I’ll get you the date, time, and location information.

Failing to Plan is Planning to Fail

Most of my parts have arrived and I am beginning the process of planning my first official scratch build.  For sure this is not a true scratch built radio like the OMs who had to learn 20 WPM CW in the 50s.  BUT my goal here is to complete a project from a schematic and learn a little about what challenges I will face in the planning phase of circuits.  I’m confident there will be LOTS of little lessons along the way….

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I Won a Tuna Tin 2

Image from www.qrpme.com

I try to attend the NORTEX QRP meeting each month.  One of the fun features of that group is that each person who attends brings some item that is excess from their junk box.  At the end of the meeting, they raffle off the items to those in attendance.  I was the first person drawn in the January 2018 meeting.  There were 2 kits to choose from.  The Tuna Tin 2 circa 2004 (link is a more modern version) and the Norcal keyer kit circa 2002.  Since I intend to build a 40M direct conversion receiver in the near future, I chose the Tuna Tin 2.  So I will hopefully make a QSO on some QRPp homebuilt gear.

Although the ultimate idea is to build and operate a homebrew transceiver while learning about radio. . . this will give me a chance to transmit a little early.

Project 1: Mission Accomplished

I said that I was going to do some homebrewing and I am.  You will see posts about that soon.  While I was waiting for parts to arrive, I have a few other projects that need to be addressed.  Project 1 is installing a Heil FS-2 foot switch for my Kenwood TS-590SG.

 

Steve — Why on earth do you need a foot switch?  Valid Question.

For the last few years I have been operating on 630M as an extension of the experimental license for KB5NJD.  As WG2XIQ/1 I’ve had a lot of fun chatting with John in the early morning hours doing CW.  Work got really busy for about a year and I got away from the habit of early morning QSOs.  Now that work is relatively sane, 630M is a real band I can operate as myself (KF5RY).  I figure not many people are on the band so I could be one of the early folks to either WAS or help someone get there.  As a result, I’m going to install an amplifier for 630M and drive that amp with my Kenwood TS-590SG.  With an external homebrew amplifier QSK is not really in the cards.  So I need a foot switch.

For my birthday I acquired the foot switch from HRO in Plano and began looking through my Kenwood box for the 13 pin DIN connector for the ACC2 plug.  I also stopped by Tanner’s and picked up a 1/4″ female jack to convert the 1/4″ jack on the foot switch to the ACC 2 connector.  All I need to do is wire it together.

After studying the manual I found that I needed pin 13 for PTT and pin 8 for ground and I’d be in business.  I studied the pins and was sure to use the mirror image as I didn’t want to get fooled by the picture translating it to my connector.  At last I took the soldering iron and wired it all up, check for continuity and went to bed feeling pretty good about myself.

Have you caught my mistake yet?

In the morning I woke up and decided to actually test the plug, in the radio.  I plugged it in and turned on the radio.  All is fine.  I stomp the foot switch and nothing happens.  I push the manual switch on the front panel and nothing happens.  I push the PTT on the hand mike and nothing happens.

I unplug the connector and plug it back in.

The radio seems to be having a seizure.  It seems stuck somewhere between ready to transmit and not ready.  There is a lot of clacking and blinking lights.  Not good. . .

After a variety of testing scenarios and tinkering, I decide that it’s not a menu setting, its something I’ve wired wrong.  So I rewire the plug on the 1/4″ jack end.  I had become concerned that somehow I had bridged the center pin and the case . . . still have a problem.  I study the manual some more.  I read about the orientation of the pins and then I realize, while it is an image of the pins from the perspective of looking at the back of the radio.  If I solder the back of the connector, it’s actually NOT a mirror image.  You just orient the connector the same as the radio and solder.  OK — I move the solder pin 5 to actual pin 8.  Should work now.

BUT I have a new problem.

The radio seems to lock into the PTT state and I cannot get it to come out of the PTT state.  I take the foot switch plug out and all is well.  I plug-in a 1/4″ jack to 1/8″ stereo adapter and the problem goes away.  . . . Why did it go away when I put the adapter in?

I take a headlamp and shine it down into the body of the female jack and it dawns on me: This is a stereo female 1/4″ jack and the male plug from the foot switch is mono.  The ring and tip are wired together in the female jack.  The 1/4″ mono plug ground sleeve is completing the circuit when the foot switch is plugged in.  No wonder its stuck in a ready to transmit state!

I take apart my wiring and cut off the ring pin all together.  It is now floating inside the body of the connector and grounded to the foot pedal each time it is plugged in.  All works FB!

All of this took about 8 hours of messing with it, testing it, trying to isolate the problem, testing it again.  Turns out I had 2 problems, but I found them!

As promised I will be posting stories of failure.  Most learning occurs when you fail.  You can only fail if you’re doing stuff.

How Do I Even Start?

As promised this blog will share a lot of failures in 2018 as I embark on my quest to understand radio.  I want to understand through building, testing, and measuring.  I want to be able to understand what is happening in a schematic and why a particular circuit might be better suited for different applications.  I want to understand what a 2N2222 is and why its different from a 2N3904.  I am hoping a few readers along the way join me in this adventure of building and learning.

OK — now that the disclaimer is out-of-the-way you might ask yourself, but where should I begin?  I mean I don’t even have a junk box!

Good question.  Me neither!  The moment I realized that this could be overcome was after listening to Bill Meara (N2CQR) and Pete Juliano (N6QW) on the SolderSmoke podcast #201.  Bill encourages his audience to build a receiver that uses a ceramic resonator and states that he will do a blog series on the steps.  Here is step one where he lists all the parts you should buy a quantity of to start your junk box.  These parts are also used to complete the project.  I reached out to Bill to say thanks for the inspiration.  He forwarded my message to Pete who suggested this post when looking for parts to start a junk box.

But where do I order all these parts from?

Mouser,  Ebay,  Digikey, and Diz the Toroid King are all good sources.  I like Mouser because they are local.  While my order isn’t keeping anyone employed really. . . It feels good to support a local business.  Diz is the place to get toroids.  I also like to go to a local electronics shop called Tanner’s.  They don’t do web orders, but its a great store in person!  A modern-day, well run, old school radio shack style store.

I’ve ordered a bunch of copper clad board, capacitors, resistors, transistors, diodes, LM 386, NE602, NE555 timers, etc.  I’m now waiting for them all to arrive and then the building shall begin.

More to come. . .

My Journey of Homebrewing

Something weird about the month of January.  I start reflecting on the last year and asking myself, did I accomplished all that I had hoped?  Well I didn’t.  But the secret to accomplishing a lot is NOT accomplishing everything on your list.   Having a list of things you’d like to accomplish. . . Now that is where the magic happens!

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South West Dallas County QRP

It was a warm day for February. The kind of day you contemplate grabbing the sunscreen before you leave. Being fare skinned and stubborn, I left the sunscreen behind. Later I would regret this decision and wish sunscreen had been the only thing I left behind. . .

I arrived about 1:02p, Dave Lear (NE5DL) beat me to Rotary Park where we do our monthly radio outings. The park was full of kids. “I’ve never seen this many people here!” I say to Dave. “Which table do you want?” was his response. Dave’s a pretty focused guy, he has the objective in mind.

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