Friday, January 18, 2019

2019 ~ Piddling in the Shack

What to do when all is does is rain?

January 22, 2019 …

January 20th, 2019. How to sample the S Meter readings.

Below I discussed The use of the LCD display and how by sampling every time through the loop that the serial processing caused the tuning knob to be essentially put on hold. I then theorized that sampling the signal say every thirty cycles through the loop would let you have the S Meter reading while not hanging up the tuning.

Mind you I am not a programmer so my solutions often seem bizarre but they do work,

  • The first thing I did was to identify "p" as an integer in the forward of the sketch. I also identified oldp as a memory of the p count. like int p = 0; and int oldp = 0;
  • In the void loop I added two lines of code The first says p = p + 1; and the second is that oldp = p; The first line simply adds the numeric 1 to the old value of p every time through the loop.
  • Next I have a sub-routine called S Meter (CheckSM();) Thus not only is a 1 added each time but the loop checks the CheckSM(); 
  • In the void CheckSM() is a simple statement that says if p = 30 (or whatever you select) then analogRead(A0) and perform some math functions. But there is more as I added additional screening software to look at the values of the math function and to display info based on the ranges of values produced -- typically it can say S3, S5 or S9+.
Undoubtedly more elegant ways to do it --- but Clunky N6QW has found a way to do it.

Pete N6QW

So OK Enough is Enough .. but more rain is on the way.

I love the Motor Trend Velocity Channel as there is such an abundance of creativity and some super cool ideas by  very clever car builders in  America's heartland. 

With all of the rain I was faced with keeping my head warm but at the same time wearing my wool beret (chick magnet) would surely spell disaster to that really FB hat. Then I thought what would the car guys do … A quick trip to the pantry where I keep the various sizes of trash bags and the smallest one cut to size made a waterproof cover for my beloved beret.

One rather attractive older woman in the supermarket check out line, upon seeing my creation, said it all: I really like men who can think of great solutions. Chick magnet works all of the time!

Trash Bag Beret Cover

The rain also caused me to spend a bit more time noodling some solutions to common problems. One problem I had as a result of the 2018 SSB Transceiver building spree was that I depleted my stock of Color TFT displays. I have some coming on a slow boat from China but what do I do today for a display? 

In looking at my bins I soon discovered I have a batch of 16X2, 16X4 and even a whopping 20X4 LCD's. I sort of gave up hope of using these as I discovered that with IDE 1.8.5 many of my older sketches hiccupped and burped as the LCD Libraries I had didn't like the new IDE. In 2018 I tried looking for some new libraries but nothing seemed to work. The rain gave me some time to once again look for new IDE 1.8.5 compatible LCD_I2C libraries. I was successful.

The next problem was that the older sketches were "clunky" and did not lend themselves to adding new functionalities like two VFO's. My newer Color TFT display sketches on the other hand did provide that capability. So the task was to meld the LCD displays with the newer Color TFT sketches. Yes Virginia not only is there a Santa Claus but I now have this..

The first thing to catch is that it is in keeping with the Juliano Blue and sports a 20X4 face. So Nice and Big! 

  • The default start up is VFO A and that is on the very first line. At the end of the line you see the word "ON" as this lets you know it is the active VFO … it is ON.
  • The second line tells the Mode and in this case a panel switch has selected Upper Sideband. That is followed by my call sign. At my advanced age it is always nice to know what is your call sign. Following N6QW, is the step tuning rate and that is changed from the push in encoder button or another SPST momentary panel switch that is in parallel with the encoder switch. Step rates of 100 (default), 1KHz, 10Khz,  and 100K are the choices
  • The third line shows VFO B and in this case the default (with USB) is on the WSPR frequency. For you FT8 guys you can make that 7.074 Megahertz. The VFO A or VFO B select is a simple grounding of one of the Arduino Pins. Now when VFO B is selected the "ON" disappears from Line #1 and now "ON" appears at the end of Line #3.It is really nice to just flip a switch and you can do FT8 without cranking the VFO tuning knob.
  • The fourth line shows an S Meter -- and this is a placeholder and merely shown as a possibility. Here is an interesting coding problem --remember I am not a coder. I wrote some math functions that sample random noise on Pin A6 and that gets translated to a numeric value. I then set up  "screening" software code that had ranges. If the answer was between such and such value then two bars appeared and if it was in a higher range then four bars appeared, At some point the display simply reads "Over S9" without any bars. That worked pretty slick! BUT! BUT! I noticed that as I tuned quickly there was no change in the frequency reading and then all of a sudden the frequency would jump by several kHz. The light bulb went on .. the Arduino was so busy making bars that it impacted the tuning changes. I nulled out the S Meter math and tuning went as normal -- remove the nulls and you have the problem back. So that is a bit more noodling on how to have your cake and eat it too. Time to think about sampling and not constant updating.
  • One other function not covered but was a clue about the S Meter updating. I also included my TUNE Tone function. Firstly I am using a UNO R3 as a development board; but then loading the code onto a Pro-Mini. Interesting first problem the Tone Library I used works FB with the Uno and Nano but not the Pro-mini. I saw this same problem with a Leonardo Board I have. But how it works with the UNO and Nano is a simple push of a Momentary Push Button which the code recognizes and for about 10 seconds a 988 Hz tone is generated and after suitable filtering (RC Filter to round out the corners of the square wave output) it is fed to the Microphone amplifier. It is a pulsed tone and makes for less strain on the IRF510 like a "Key Down" situation. In one variant I even send in Morse code my call sign. Now the clue --while the Arduino is creating and transmitting a pulsed 988 Hz Tone -- if you turn the VFO dial nothing changes on the display. Thus the clue that the Arduino is a sequential processor, which it is. In the lower right hand corner when you invoke the TUNE button the word TUNE appears on the screen so you know you are in the TUNE mode.

I have a plan for collecting some more parts /assemblies lying around and following in the footsteps of the Velocity Channel guys "fabricate" yet another rig (the 2nd for 2019).

Keep on building.

Pete N6QW

Saturday, December 29, 2018

2019 ~ The Year of Change ...

2019 N6QW New Year's Resolutions!

  • My Soldering Iron will always be Clean and Bright!
  • I will RTM before starting any project.
  • I will have the bins always stocked with parts.
  • I will endeavor to keep the work bench neat and tidy!
  • I will unsubscribe from certain reflectors.
  • I will endeavor to use my website as the only place to share ham related info.
  • I will wean myself from making trivial electronic videos on You Tube.
  • I will endeavor to "step up" the technical aspects of my projects. 
  • Closing Out 2018 Projects...

Happy New Year from N6QW.


Saturday, December 22, 2018

2019 MAGA ~ More Arduino's Greater Advancements

What Ham Radio Needs?

December 26, 2018 ~ The Day After ..

Well I did get one radio related gift from my middle son and his XYL. Parts! Yes I got three bags of parts... one of caps, another of diodes and zeners and the third of inductors. So not all bad.

In thinking about MAGA ~ More Arduino's Greater Advancements. I have come up with several "tools" built into one Arduino.

First would be a simple band switched RF Oscillator. This would provide outputs in the ranges 1 to 3 MHz, 3 to 6 MHz, 6 to 10 MHz, 10 to 15 MHz, 15 to 22 MHz and finally 22 to 30 MHz for starters. These would all be step tuned in increments of 10 Hz, 100 Hz, 1K, 10K, 100K and 1 MHz tuning steps.

Also being considered is fixed frequency outputs for testing IF stages like outputs at 4.9152 MHz, 9 MHz and possibly 10 MHz or other chosen frequencies (CLK2).

Next would be audio related such as Two Tone generation for Linearity testing of RF Power Amps and to provide fixed tones for use in checking audio amplifier stages.

In our age of do it fast and thinking about those who take a guilt trip about not doing CW ( I am not in that camp), four push buttons would provide the following:

  • Button #1 calls CQ in CW
  • Button #2 responds by saying your report is 599, Name is Pete, QTH is Newbury Park, CA
  • Button #3 says Rig here is homebrew running 800 watts and antenna is a droopy dipole
  • Button #4 says Tnx fer the QSO nice to wrk you 73's.
There now that would be useful and the only skill is button pushing and no sending skills required.

Possible other implementations (mind you all in one Mega2560 Arduino)

  • Return Loss Bridge
  • SWR Bridge
  • Coffee Pot Timer
  • Station ID timer
Hope you got some nice stuff for Christmas.

Pete N6QW

We Need More Simple Projects Using the Arduino Nano. Thus our new slogan:

MAGA = More Arduino's  Greater Advancements

In 2019 I hope to develop some projects that may be useful in the shack. Some may involve test instruments while others may include projects like remote antenna tuners. However, all will be Arduino based.

For those who await new projects with baited breath [or just plain bad breath], having built so many transceivers in 2018 there will be no new transceiver projects in 2019. I guess I should never say never.

Happy Holidays and may you find a gingerbread person in your holiday stocking.

Pete N6QW

Saturday, December 15, 2018

2018 ~ The year of SSB Transceivers

The Year is Just About Over!

WSPR Data from RIB 12-18-2018. The rig has passed the tests!

This is the "last gasp rig' for 2018.

Don't try this with your Bitx40 or uBitx!

What Drives Ham's to do insane things?

When does a Vision become an Obsession?

Who would have thought this was possible?

Does Tribal Knowledge Apply?

Would QST ever cover this Project?

When does an idea spark a project?

Does being inebriated help?

Who else has done this?

Is this just a toy?

Why is this not a published article?

Is this a dare or a challenge?

Is this a project for a newbie homebrewer?

This is a "Ship in  Bottle"

This is a "Rig in a Bottle"

Happy Holidays!

Pete, N6QW

Tuesday, November 27, 2018

2018 ~ The Year of SSB Transceivers

Why you should NOT build your own Rig!

There are many proponents of the concept of building your very own homebrew station frequently involving more than a simple CW transceiver. Often the discussion will start off by saying this is how the hobby started, or a true ham is more than an appliance operator. Still others will say that it is through the understanding of the form, fit and function of each and every component will you then and only then appreciate fully our hobby. 

Today I want to explore the many reasons why you should NOT build your own rig. This seems strange coming from me; but I do want to relate some personal experiences that support this argument. 

My published works both formally via mediums such as QRP Quarterly and the GQRP SPRAT and Hot Iron and on my websites, you tube videos and N6QW blog contains about three dozen transceiver projects with about 98% being SSB and the other 2% --you know the other mode CW. 

This sharing of knowledge has frequently generated lots of email and lots of questions. Quite often the questions reflect the real desire to homebrew a rig but too often that the prospective homebrewer lacks the gravitas to pull it off. I respectfully try to answer all questions without being derisive or resorting to comments such as "Stop you won't make it."

I have been keeping a collective of the reasons why these individuals should not attempt building a homebrew rig and this listing may serve as a roadmap of what needs to have the box checked in order to be successful. Basically you can group the reasons into lumps such as 1) Basic electronics knowledge 2) Lack of experience 3) Lack of test gear 4) Unfamiliarity with the new technologies and 5) A large Junk Box

  • Building electronic circuits requires some basic knowledge such as understanding Ohms Law, LC Circuits, DC versus AC circuits, and all important, mathematics beyond addition and subtraction. Resistors in parallel are product over the sum. Now we have multiplication and division. Capacitors in series follow the same construct. Oh and which is the collector, base and emitter pins. Did I also mention you must know how to read schematics; and being able to work with LT Spice is a must!
  • It would be something short of a miracle to successfully build one of my SSB transceivers without having previously built something. A SSB Transceiver is not a first time project! There is much tribal knowledge to building RF circuits without having them oscillate, or be subject to unwanted feedback. Often "newbies" think they can homebrew a crystal filter simply by purchasing 5 crystals and you are done. You may need to buy 30 such crystals and then proceed down the path of "black art" to finally end up with a workable filter. Again a miracle complete with a star on the horizon will not net a good filter without some large experimentation being involved.
  • A person once shared that he built a one transistor CW transmitter and couldn't tell if it worked as the only receiver he had was a crystal set.  He did not own a VOM, did not have a SWR Bridge nor did not know what a RF probe was. Dabbling with electronics today means some basic test gear like a Digital VOM, LC Meter, Digital Storage Oscilloscope, SWR Bridge, Dummy Load and test oscillators. Yes some are big ticket items but inexpensive high quality analog Scopes can be had at very reasonable prices. You also need a linear or high quality switching power supply --forget the WalWarts!
  • I can build a digital VFO with an Arduino, Si5351, and a Color TFT Display for about $20. BUT unless you know how to program the Arduino and how to connect up the Si5351 with Color TFT --all you have done is spent $20. Too many times I get an email --"your code doesn't work and when I hooked up everything nothing shows on the screen". Invariably the person ignored the documentation and simply counted the pins on the Arduino --- D3 is not third pin on the Arduino (it is actually the 6th pin). That follows that D12 is actually the 15th pin. They ignored the many project write ups that discuss the IDE being used and the need for included files. In short they never invested the time to go through the Hello World tutorial or LED On LED Off exercise. Their 1st experience should not be  is a band switching, two VFO sketch -- not for the faint of heart. Purposefully I put splash screens in my code as an irritant so that in time you get tired of seeing Seabee's Can Do which will force the user to change the code. Also noteworthy get used to surface mount parts.
  • I buy parts in bulk and have a large junk box -- you can buy 10 resistors for $1 or 100 for $4. There are many common value resistors that are used over and over. Values like 100 Ohms, 1K Ohms and 10 Ohms. A bit of judicious buying can net a nice junk box. A $20 bill will get you 500 resistors of 5 most common values. The same applies to capacitors -- the two most common values are 10nF and 100nF -- same deal only a bit more expensive as these are typically 100 pieces for $6 or $7. But unless you have been stocking up; buying parts in small quantities will make the project cost an arm and a leg.

There are some other issues such has having a few good tools including  a temperature controlled soldering iron with a fine tip so you can work with surface mount parts and an electric drill ( Li Po battery powered are nice). A variety of good quality screw drivers and needle nose pliers along with some "nippers" and an Excelite socket set round out the mix.

There are many other tools and techniques like bench vises, metal benders, Drill Presses, CNC mills and 3D Printers round out some ham shops.

Above all is the time investment to learn about the hobby, how to do things (you tube) and you will have to invest in buying reference materials. Typically EMRFD is suggested as a reference document and I can tell you my copy is doing yeoman's service as a bookend. Harder to find is Solid State Design for the Radio Amateur -- more useful. You must set up your computer so you can find stuff. You must also tune into blogs and You tube videos from Charlie ZL2CTM and DuWayne, KV4QB and of course N2CQR's SolderSmoke Blog. That is a big time sinkhole to read all of that stuff.

So why would you even think of homebrewing a rig when you can buy rigs that almost make you feel like you are homebrewing a rig as you do have to do some work to get it on the air -- but that is mostly mechanical stuff.

  • Ashar Farhan's Bitx and uBitx kits get you there ranging in price from $60 to $140. (Mostly assembled & tested)
  • Hans Summers QCX and QSX kits in the same range gets you there for about the same $$$
The value of these two kit suppliers is that they are proven kits and have web reflectors for help. Scratch building a rig and not having in depth knowledge or the proper tools or test gear ties both arms behind your back and there is a high probability of failure.

So don't even think about homebrewing a rig unless you can check off all of the boxes. I have 60+ years doing this and might add -- 60 cumulative years not one year 60 times over. Thus I can build rigs because I can and should add every once in awhile even I end up with smoked parts where a rig once stood.

So if you want to get on the air and make contacts, buy it don't build it. (unless you follow what you need to do).,

Pete N6QW

Sunday, November 18, 2018

2018 ~ The Year of SSB Transceivers

A New Transceiver ~ Dual Filter Rig

11/23/2018 ~ A case for "Troubleshooting".

Since much of the prep for Turkey Day are now over thus I had a few spare minutes to work on some radio projects. I needed to use a bigger wattage soldering iron to "weld" some copper PCB cases together. When I plugged in the iron purchased from MPJ in FL, the ON LED  was intermittent and the iron would not heat. This required a disassembly of the controller since I knew the iron itself was good. 

What a bear to get that case apart but I did manage to get the unit out of its case. Actually the soldering control box is kind of cool as it has a detachable 3 prong cord and built into the unit receptacle is a fuse assembly and upon checking the fuse discovered there was even a compartment for a spare fuse. The fuse checked good so that was not the issue,

I "jiggled" the wiring from the transformer to the board and saw the LED flash on/off. Boom, a loose connection. But interesting was that the PC board was burnt around where the wire from the transformer to the board and the solder connection looked like it was a cold joint but much evidence of burning. The wire connection evidently was loose and arcing which would cause the burning; but it would have to get awful warm to cause the solder to have that cold joint look. All other wiring to the board which went to the actual soldering iron itself looked "kosher". 

Thusly I cleaned up the solder joint and re-soldered the wire -- and before installing  back in the case tested the power ON LED -- we were good. So everything buttoned back up and I installed the soldering iron. With the fine tip point -- it worked AOK. But when I installed the 3/16"  wide screwdriver tip it would not get hot enough to melt thicker solder.

So there must be more to the reason behind the loose/burnt wire and now back to opening up the case again to do more trouble shooting.

You cannot have too many soldering irons and I have five of them. Two look like brothers --one was purchased from Marlin P Jones (detachable cord) and the other from Circuit Specialists. Same case but different logo; but the one from Circuit Specialists has an integral cord and no external fuse.

So I am at a loss --both units were under $30 and the one I use for hardware connections is an Xtronic which cost me about 2X that -- it is nothing to write home about. 

Anyone have any soldering iron recommendations?

Pete N6QW

Only 6 weeks left in 2018 --need to get cracking if I want to build at least three more rigs this year. Keep in mind that I reuse many of what I call standard building blocks. Thus using these standard circuits enables fitting together what I call electronic Lego Blocks. Having the Digital VFO/BFO vastly reduces the prototype time.
A Bit of WSPR & FT8 on a Totally Homebrew Station. 11/20/2018

Earlier this year I cobbled together a dual filter rig and sort of just put it on the shelf after getting some early results. By dual filter this topology means that there are separate LSB and USB Filters and to switch sidebands the BFO frequency is fixed and the filters themselves are switched to either sideband. Drake used this method as well as many commercial manufacturers. This has some charm in that you only need to contend with coming up with one BFO frequency.

Late in 2017 I spotted a surplus crystal filter board that contained a set of the filters as well as a 3.6 KHz AM filter and the center frequency is 9 MHz. The surplus board is sold on eBay by a firm in Israel. The filters are made by KVG (Germany) and are quite excellent. The specifications for the filters appear as a later photo. See the link below --now about $38 delivered. I paid $34

The amazing thing is that I got the board shipped to my QTH for $34. The filters are installed on a circuit board that contains many useable parts --some are unobtanium! These boards I think are still floating around and the price is roughly the same. I decided to make the rig a multiband rig but currently only the 40M BPF and LPF installed. I am impressed at how good it sounds.

The line up is as follows:
  • It is a bilateral rig that uses the Plessey amps (2N3904/2N3906) ahead and following the dual filters. For the Rx Tx Mixer I used an ADE-1 and for the Product Detector/Balanced Modulator, a second ADE-1. To switch sidebands.I used diode steering. It works very well. 
  • The audio stage is a 2N3904 and LM386 and the Microphone amp is a 2N3904
  • The Rx RF Amp and the Tx Pre-Driver use the same stage which is a pair of J310's configures as a Dual Gate MOSFET. A couple of relays steer the signals through this single pass amplifier. 
  • The Driver stage is a single 2N2219 and the final is an IRF510. 
  • Recently I built a an Arduino/Si5351 into a repurposed copper PCB box that formerly housed a RF linear amp. This now is the control panel.
  • The rig puts out 5 watts but I can put two RF linear amps in line for a whopping 600 Watts +. With that configuration I worked EA3JE, Lou in Barcelona in the middle of the day on 40 Meters. Lou said I was 10/9. So this rig will run with the big dogs. Then today I worked Hawaii during the SS contest running QRP. My antenna is a sub-optimum 40 Meter dipole on a postage stamp sized lot.
  • The rig uses two 4X6 copper PC Boards that are stacked on top of each other. The  bottom board has the filters, the Rx Tx Mixer and PD/BM. The top board has the Audio/Mic Amp, the single pass J310's, the BPF , Driver stage and the TR relays
  • External to the stacked boards are the Control Panel, the IRF510 and Heatsink and the LPF.
  • Controls Include, MOX, Tune Button. USB/LSB Select, Band Select, Main Tuning Audio Gain, Microphone Jack and Audio Jack.
  • This rig like others I have built provides a 988 Hz Timed Tone for Tune Up. Sure beats screaming Hola into the microphone. A screen display of TUNE in Red is shown when in the Tune Condition. How cool is that?
  • This is not a compact rig but does facilitate experimentation which is always a desirable goal.
There is just something amazing about fielding a totally homebrew station and this new dual filter rig is just that -- totally amazing. But the icing on the cake is that you can run the digital modes --that too is also homebrew. Many in our hobby can do also do this same feat. So my skill set is not totally unique or one of a kind but it does speak volumes to learn the "how". It is simply too easy to whip out the plastic and you are there. There is also a tribal knowledge factor --I have been doing this for 60 years which flies in the face of some response such as I am too old. You can do the math -- I got licensed when I was 17. Back in the old days you had to build much of your own station and plastic was not in widespread use. So make yourself a New Year's resolution to totally homebrew a rig for 2019. Sideband would be nice but CW will suffice.

Pete N6QW

PS Still on the bench are at least three more transceivers projects including one not unlike what Peter Parker, VK3YE built as a single channel 40 M SSB rig only on 7.2 MHz. I am noodling a really small, trail friendly, portable rig using surface mount technology and no VFO. Thanks Peter for the inspiration. Another is to rip out the crystal switched VXO from a  the 17 Meter rig and install a Pro-Mini and 8X2 LCD. The 3rd is a mystery project. Can this all be done in 6 weeks?

2019 ~ Piddling in the Shack

What to do when all is does is rain? January 22, 2019 … January 20th, 2019. How to sample the S Meter readings. Below I discussed...