Friday, February 8, 2019

2019 ~ Building SSB Transceivers

The Building of a SSB Transceiver ~ You can do it!

2/21/2019 ~ Go Daddy Now Fixed! The audio Amp Schematic is on the website.

2/20/2019 ~ Problems with Go Daddy!!

For over 24 hours I have been trying to upload updated schematics and information to my n6qw website. It seems like Go Daddy who hosts my website has some sort of issue with a windows server. One solution that offered was for me to spend more money and move over to a Linux server OR just wait until they get around to fixing the problem. Not only is it a cost issue but also I would have to start from scratch and rebuild all five of my websites. This makes about as much sense as declaring an emergency so the emperor can have his wall. 

My alternative is to wait a bit longer to see if they can resolve the problem or just post the info here. Here is one of the updated schematics. Perhaps if any of you have a Go Daddy account you may have the same problem.

Pete N6QW





2/18/2019 ~ Toroids are not self shielding!

I noted that after installing the shield on the left hand side there appeared to be a detuning of the band pass filter. Despite what many have said toroids are not necessarily self shielding. 

When I installed the side piece, I thought there was a sufficient space gap between the steel based side panel and the T-68-2 cores. There was not and so the BPF was being detuned. There just was no way with the side panel in place to re-peak the BPF to the proper value unless I followed the practice espoused by Ian Roussel (Full Custom Garage on the Motor Trend Channel) which is make a hole.. The "A" change was to cut about a 1 and 1/8 inch round hole in the side panel stiffener right over the BPF. This accomplished two things. Firstly it reduced the effects of the steel on the BPF and secondly to provide access to the trimmer caps so that the BPF can be tuned with the steel side piece in place. Worked perfectly -- the hole does not affect the stiff properties of the side bracket. We are good to go. The 2nd photo below shows the side piece without the access hole. You have got to love when a plan comes together!

Pete N6QW



2/17/2019 ~ Be sure to visit www.n6qw.com where the project is documented  and new schematics have been added over the past two days. 

Learning to Hem ~ No we are not sewing!!!


In keeping with trying to use stuff I already have knocking about the shack we now address a common problem with homebrew construction: making or buying a case enclosure. The problem is compounded by the fact the front panel is  from the former 30M CW transceiver project that was a QRP Quarterly article. But the back panel came from a transceiver that was rebuilt at least three times. 



Now for the disconnect. The front panel is 4 inches high and the back panel a mere two inches. Standing alone the front panel flexes as you spin the encoder --not a good plan. Thus to stiffen things we need to connect the front panel to the back panel to add rigidity. We essentially have a trapezoid and how to fabricate those two pieces, one for each side, and not spend a fortune on material.

One of my currently favorite TV shows is the Velocity Channel (now Motor Trend) and my new hero is Ian Roussel of Full Custom Garage. This guy uses what is at hand and often comes up with very creative solutions. In one episode he needed a round metal structure to house the odometer that was being affixed to a new dashboard. He spotted his dog's water bowl which it turned out was stainless steel and just the right size. The poor dog now drinks out of a plastic dish. But it is that sort of thinking we need to employ when we fabricate our homebrew rigs.

A trip to Home Depot yielded a piece of galvanized metal flashing that was about 8 X 11 inches. The price was $1.14 and was enough material to make two sides. But wait you are thinking that stuff is awful flimsy. True; but if you bend it over along one of the seams --it becomes rigid. A pair of Tin Snips, a metal straight edge with scribe and a bench vise is all that is needed to make these very durable side braces. The galvanized metal can be soldered as well as painted. Thus the bending over and doubling is known in the fabrication world as "hemming".

The first item on the list should be a manila folder that will serve as a pattern to overlay on the sheet metal and provides a template to scribe the outline. Keep in mind you have right and left hand pieces and thus you must flip the pattern over to draw the scribe lines for the different sides. The 1st photo below shows the template of the sides and you can see the bend line for the hemming. On either end add 1/2 inch of material that is bent over and will provide the anchor points to the front and back panel.

You might have to "play a bit" with the metal bending so get two sheets of the material. The finished rig is a far cry from the boards screwed down to work bench as it was initially built. Nice looking Rig, Pete!

Ian Roussel would be proud.

Pete N6QW









2/15/2019






2/13/2019

[2/11/2019 I have started publishing schematics for the Simple SSB on my website at www.n6qw.com. Although it is doubtful that many (if any) would take up the fabricating of this rig, there just may be one or two who have an interest.] 



Just the other day I was having a very nice QSO with Gene W6QFU and we exchanged our station line up. W6QFU is lucky in that he just recently acquired a very nice ICOM 7300 and has joined the ranks of perhaps over 100,000 other hams world wide who now have that rig sitting at the operating position. Some would suggest it is an appliance rig; but at the same time it is a great sounding rig that undoubtedly is very popular and the current price point puts it in reach of many hams. Guess there is a link to price point and the numbers in shacks around the world.

On my end --yes, yet another new rig just finished and W6QFU was the third contact on that rig. So I was anxious to see how it held up. Well I might add...

ARRL as previously reported will start a new podcast one month from now called "So What Now?" A possible answer to that question (or perhaps it is a challenge)  is to suggest you build your own SSB transceiver. Trust me what I am suggesting you build is not in the ICOM 7300 class; BUT it puts out a respectable signal with a rock solid frequency stability and it is something you built and can be built for about $100. [YMMV depending on how much junk you have in the junk box.]

But let us go back in time to review SSB transceivers starting in the late 1950's and early 1960's. BOOM there was an explosion of technology in that time frame starting with the Collins KWM-1 and KWM-2 (the cost --read a years salary for most middle class working folk) to more modest rigs that were less costly. Heathkit did much for the hobby in offering single band transceivers that could be had for about $100. I remember being on Midway island (actually two island Sand and Eastern Island) in 1963 where a fellow Navy ham on Eastern ran one of those rigs into a 13 dB gain Rhombic antenna pointed at the US. Everyone wanted to talk to him--firstly he was DX and secondly that gain antenna took that 100 watts and made it look like more than a KW (like 2KW and you can check the math [10*log(2000/100) = 13dB]) But even the simple Heathkit rigs involved some pretty complex circuitry to receive and transmit a signal using common circuit elements. 

There were many complicating factors in building a homebrew SSB rig in the 1950's and 1960's

  • Socketry --yes you had to do all of that metal bashing and mechanical engineering to layout all of the tubes and components that had to be affixed to a large aluminum chassis
  • Power Supplies. You often required Filament, Bias, LV, HV and control  power to operate the rig. We are indeed fortunate --12 VDC and we are there today
  • Front panel controls abound as does a space reservation for the Analog Dial Readout
So there was much involved aside from just a few schematics.

In todays rigs none of those issues exist as many circuit elements simply solder to a few pads. Socketry is minimized so you can feel secure in selling your set of Greenlee Chassis Punches at the next block yard sale. You won't need them. A 12 VDC well regulated supply or even batteries can run your rig. You only need to cut out a rectangular hole in the front panel for your favorite display (LCD or Color TFT). If it is a touch screen then that will reduce further the number of controls needed


Fast forward to today some 60 years later and building a transceiver is much easier and uses far less components thanks to IC's, PLL's and inexpensive commercial crystal filters. Let me take a moment to discourage the use of homebrew crystal filters especially if you have not previously built one, and two if you lack some pretty decent test gear. Sure you can purchase crystals inexpensively but that is only 5% of the task. So reject all of those claims that you only have to buy 5 crystals at 40 cents a piece and you are there --you aren't! INRAD sells a nice 4 pole 9 MHz experimenter's filter for about $30 and you can also buy 9 MHz filters from the GQRP club for about the same shipped to you. Yes I do have several rigs with homebrew crystal filters so I do speak with experience. But it is a simple decision if you do not have that experience --buy the filter!

So lets talk a minute about the SSB transceiver architecture. and  we'll proceed first to the  block diagram. 





Many rigs today are bilateral or as some prefer bi-directional in that a) signals can be routed in two directions through the circuit element and b) because of (a) you can use that circuit element in both transmit and receive.

Here is an example of one circuit element that I frequently use... a bidirectional IF Amplifier Module as shown above. This module has four transistors, a bunch of caps and resistors, two matching broadband transformers, a crystal filter and a relay to bias parts of the circuit to change the signal direction. The common 2N3904 and 2N3906 make up one amplifier stage and following the crystal is a second identical stage. The amplifier circuit was invented by Plessy and appears in EMRFD (just so it has street creds). Here is what is happening .. with one bias condition the two 2N3904's take on the amplifier role. With the alternate bias condition the 2N3906's are doing the heavy lifting. This circuit is good up to about the 6 Meter band and a single amp pair is good for 15 to 17 dB of gain. 

Here are some notable items. This is a broad band circuit --there are no IF transformers and there is nothing to peak or tweak. The resistor compliment for a single amp stage is 22 Ohms, 2 X 100 Ohms,. 2X 680 and a 1K. For caps -- six each 100 Nano Farad. The power source is actually 6 VDC but I run mine on 8 VDC through a three terminal regulator. Add in two FT-37-43 matching transformers [19 Turns solenoid wound tapped a 6 turns. The 19 turns squared is 361 and the 6 turns squared is 36 --thus 361/36 = 10. So this transformer matches the 50 Ohms of the Plessy to the 500 ohms on the GQRP filter.]

Including the Linear Amp control ( another 2N3904) there are eleven transistors and FET's along with two packaged ADE-1 Double Balanced Mixer's an Arduino Uno R3 (because it was in the junk box) a 16X4 Seasick Green LCD (also a junk box refugee). BTW I was looking at some 16x4 Blue White LCD's --$8 shipped from the USA. Lest I forget the GQRP 9 MHz crystal filter. If you use the INRAD it is a 4:1 match as the INRAD's are 200 Ohms.

This may be a good place to stop for now… but to whet your whistle:



Interesting note this front panel was cut out of the front panel that was used for the 30 Meter CW transceiver that originally was a QRP Quarterly article. I should tell you that I was encouraged by QRP Quarterly to design and build this CW rig so it would appeal to those QRPer's who dominate CW. I did as was suggested and did make one contact to prove it works . The rig then went into the never to use again and possible use in other projects bin. There it has sat for five years. Now is the time to use it!

The panel was reversed as it was double sided PCB. The Key is now the Mic jack and where the analog dial was --it was cut out for the LCD. The audio amp stage was cut out of the original main board. There are three empty holes in the new panel. Above the red knob the audio gain control will be installed and the hole in the lower right hand corner will house the audio output jack. and the small hole next to the mic jack will be filled with a bolt and nut. The original panel was 8 inches long and with a bit of juggling and cutting material off of each end the size is now 6 inches wide. 

Thank you Velocity Channel for giving me some really great ideas! Yes Virginia having a CNC sure makes life a lot easier when you are fabricating radios. The part that was cut off included the former part containing the volume control and headphone jack. The two bolt holes nearest those were enlarged to house one of the toggle switches and the new headphone jack. 

New panel controls include MOX and TUNE button (red button), Volume control, Main Tuning, USB / LSB Select and VFOA / VFOB Select, Microphone Jack and Headphone Jack. Lest I forget the 16X4 LCD.



Below is the rig screwed down to the top of the work bench. In the very bottom is the IF module, Audio amp and Microphone amp. To the left of the IF module is the BPF and above the IF the bidirectional J310 amp and the single 2N2219 feeding the IRF510. To the right of the IRF510 and the microphone amp is the LPF. The junk in the center is my power buss and some relays used for TR. The RCA plug/cord above the J310's is the linear amp control. The "T" line feeds a 1K resistor into the Base of a 2N3904 with the Emitter grounded at the collector goes to the control line in the follow on linear amp. 

Take a good look --aside from looking like crap --there are not many parts. I did use it on WSPR and FT8 as well as a few SSB contacts. the future work will involve some packaging to sanitize the look. 
!



It is a shame that many hams think building a rig is too difficult. Drop me a comment if you would like to see more detail on this project. Oh should mention portions of the design are LT Spice simulations so there is solid science behind the modules. These include the BPF, LPF, the J310 Bi-Directional amp, the 2N2219 driver stage and the microphone amp circuit. Oh --the mic amp design is now the same design used in the audio pre-amp stage. The circuits not simulated are the Plessy amps (from EMRFD) and audio final stage LM386 and the IRF510. 

I was asked a question about how the Simple Transceiver compared to the Sudden Transceiver Project. There are two areas of comparison the first of which is performance and the second the circuit elements themselves. Performance is equal and thus I am pleased; but the circuit elements do differ and the following explains the differences.



There is some circuits which are alike and some not so. Physically the Sudden is a smaller footprint. Some circuit differences include:





  • The IF Module uses the Plessy amps and external DBM’s. The Sudden using the NE602 provides the mixer stage and the balanced modulator on the input side and the mixer and product detector on the output side. The LO & BFO are switched whereas in the  Simple SSB rig they feed the same DBM regardless of T or R. The Sudden is a single pass whereas the Simple is bidirectional.
  • The simple SSB takes the pre-driver used in the Sudden and makes it bi-directional so it is the Rx RF Amp on receive and Tx pre-driver on transmit. The Sudden has a separate Rx RF Amplifier stage
  • Only one BPF versus two in the Sudden
  • The Driver and Linear Amp are the same
  • The Mic Amp is the same but the Audio Amp different
  • The Sudden uses a Color TFT and Nano and the Simple the Uno R3 and the 16X4 LCD
  • The LPF’s are the same.





Bottom line ~ not a lot of parts! For those who wonder this is not a Bitx40 repackaged. The Dual J310bi-directional  stage configured as a Dual Gate MOSFET has some interesting possibilities. The stage has a manual gain control pot built into the circuit board so that stage gain can be adjusted. This opens up some potential for adding AGC and ALC to this stage so now we can add more additional refinements. One comment I made arising from the Sudden Transceiver fabrication  was the opportunity for experimentation. With a change in the BPF and LPF the Simple SSB Transceiver can traverse to other bands. A simple DPDT toggle switch on the front panel could with 1/2 the switch  controlling the VFO range and the second half controlling 4 SPDT relays would switch in the proper BPF's and LPF's for each band. One switch, four relays and a few more toroids and caps and you are on two bands. 






73's
Pete N6QW

Wednesday, February 6, 2019

2019 ~ Retrofitting Old Boat Anchors with New Technology

Turning an Old Boat Anchor into a Silk Purse. Yes it involves the Arduino!!!!


I frequently tour eBay looking for bargain "Boat Anchors" that can be easily retrofitted to work the bands with rock solid frequency stability. Most of these old boat anchors suffer from drifting "ANALOG" VFO's. Yesterday I came close to acquiring such a rig. Early on Yaesu marketed some rigs that pre-date the highly successful FT-101 series of transceivers.

One such model is the FTdx-100 and I had one of those about 7 years ago and you can see how I "worked on that rig" on my website www.jessystems.com. Recently I spotted a Sommerkamp FT-100, virtually the same gear marketed by Sommerkamp in Germany along about 1966.



My complaint about the FTdx-100 was that it lacked DFMA.

[ For those who did not spend half their life in aerospace manufacturing DFMA is defined as Designed For Manufacturing & Assembly. Bottom Line you can service what you build without a total disassembly of what is built. I go into detail on my jessystems.com  website about how I was unable to replace the HV electrolytic caps because it meant removing a significant part of the under chassis wiring. Guess in true Japanese fashion they reasoned this will never have to be repaired because the quality was built in. Well caps get old and need replacing!]

But is was a marvel in that it was a hybrid rig that used HF Germanium transistors in the lower level stages and three tubes for the output stage. A 12BY7 driver and a pair of 6JM6's are in the output stages. BTW you can buy a matched pair of output tubes for about $25.

The FT-100 was particularly appealing in that it had a panel switch to select an external VFO or you could have crystal control of the receiver and transmitter.(Same for FTdx-100)

Now for the bonus part (and the Arduino). The primary analog VFO had a range of 8.9 MHz to 8.4 MHz. Yes it was a backward tuning VFO! There was a circular analog dial that had two sets of markings and these were 0 to 500 and 500 to 1000. On 80 and 10 meters you used the 500 to 1000 dial reading and on 40, 20 and 15 Meters you used the 0 to 500 scale. Thus if the dial real 250 that meant on 40 Meters you were on 7.250 MHz or on 15 Meters then the dial read 21.250. But at the same location if you were on 75/80 Meter you would read 3.750 MHz and for 10 Meters that would be 29.250 MHz for the reading. 

So now the trick is how to do that with an Arduino and an LCD display. Actually the effort involves building an external VFO that would have a 5 position band switch. The use of the band switch does two things: first is to signal and display what band it is on and secondly to choose one of two constants to perform some math functions. The only interconnect to the Boat Anchor rig is a small chunk of coax.

So how can we make the display (I chose an LCD) read 0 to 500 on some bands while reading 500 to 1000 on other bands. Keep in mind no matter what band, the VFO is on a constant range (8.9 to 8.4 MHz) and secondly works backwards (for the newbies that means at the low end of the band the VFO is at a higher frequency). 

A little time with an excel spreadsheet reveals the two numbers 8900000L and 9400000L. (The "L" is for large numbers that you identify in the sketch). 

So if you were on 40 Meters and wanted to read 250.000 (7.250 MHz) you would subtract the actual generated VFO frequency from 8900000L. Since .250 is half way between 8.9 and 8.4 the actual VFO frequency is 8650000L. When you are at 7.0 MHz then the subtraction is 8900000L - 8900000L = 000.000. So for three band positions the constant is 8900000L.

Now for the problem with 80 and 10 Meters. There we have to have a higher reading on the LCD for the same actual VFO frequency. Let us pick 3.750 MHz for our example. Yes the actual VFO frequency is the same as for our 40 Meter example 8650000L. But our LCD would have to display 750.000. Thus our constant would now be 9400000L. Thus if we take 9400000L - 8650000L the answer is 750000.

So our sketch logic would be to generate frequencies in the range of 8.9 MHz to 8.4 MHz and to limit the tuning range to that 500 kHz segment. There is a range limitation code in the software but you do have to make it 1 higher and 1 lower so that the display will in fact subtract and essentially read 0 to 500 and 500 to 1000. The other aspect is to decode the band switch so that the proper band is shown on the display and that the correct constant is used for displaying the range. As you tune the encoder the top line will show the operating 80 Meter frequency and the 3rd line the actual VFO frequency. As you change bands the 80M will change to the band selected and as you tune the encoder depending upon the band the top line will range between 0 to 500 or 500 to 1000.



Too bad I was not the successful bidder as the addition of the digital VFO would have made this a great boat anchor. The reason for the last line --later on Yaesu did make an FT-100 in a solid state version. I do not think it was around for very long.

73's
Pete N6QW/

Sunday, January 27, 2019

2019 ~ News from a Knackster

ARRL Announces new Podcast.

[BTW Michelle and Joe, your new found audience may actually want to build some hardware like this totally homebrew FT8 station . But that may put your advertisers in a snit as it means build not buy. Sorry for being so snarky!]


Boom, seems like the ARRL is trying to play catch up... A new Podcast is about to start on March 7, 2019 aimed at the new hams who have questions. It is called "So What Now".

The show premise is Michelle (the newbie) has questions of Joe (the OT) and is sponsored by LDG. Wonder what the ratio of plugging antenna tuners to actual technical content will be.

The show runner states this is the first ever podcast aimed at helping new hams (and ostensibly keeping them in the hobby). N2CQR has been doing this for over 10 years  on his Solder Smoke Podcast and for the past three years I have been riding along with Bill. So maybe ARRL is not the first.

For many segments of Bill's Podcast the subject has been the Michigan Mighty Mite Transmitter ala CBLA (Color Burst Liberation Army) and using this as a jump off point to learn about the hobby. 

So if you are an ARRL Member and SolderSmoke Podcast listener you might want to drop the ARRL a short note and suggest they listen to back segments of Bill's Podcast.

Any effort to keep the ham community strong, vibrant and growing is most welcome and so is this effort by the ARRL. Good Luck Michelle and Joe.

My gripe is that there are many other podcasts (aside from SolderSmoke) that are aimed at helping the new hams get a solid grounding and have been doing so for a long time. It is the arrogance of the ARRL to suggest they are the first that is bothersome.

73's
Pete N6QW  



Knack News!

What happened to FT-8?


I like to use some of the digital modes not for contacts; but for rig testing. For instance if you place a QRP Rig under WSPR control you can have a record of what you are hearing and who is hearing you. It also tells you much about your antenna as to directivity and if what you have actually is more than a "wet noodle".

So it was a natural event to take the rig shown below and to do some testing using WSPR and FT-8. I have the WSJT-X software loaded on a Windows 7 Netbook and  Windows 10 computer that is the size of three stacked CD cases --read small footprint. In doing my tests I started with the Netbook and WSPR did FB and then I decided to test FT-8. Hmmm strange --I could see the signals on the waterfall and I could hear the signal in the external speaker BUT nothing decoded. Back to WSPR and all worked well. So next I went to the Windows 10 machine and the same problem WSPR OK but FT8 --Nothing!

So having been around the pole I thought about a Windows update from Microshaft that might be the culprit; but ruled that out as the WSPR probably would not have worked. So it had to be the WSJT-X. I had downloaded the WSJT-X in the fall of 2018. Well it turns out that in December, 2018 WSJT-X 2.0 was released and so if you want to decode anything you need 2.0. A quick remove software and add WSJT-X 2.0 and we now are decoding the stations. 

The new software looks complex as there are many versions to download -- it seems like they even have a version if you want to sit on the toilet and work DX via FT8 from a iPhone there is a version for that too!

So if your FT8 has stopped working -- check your WSJT-X version number it has to be 2.0 or greater. What a waste of an hour!!!!!!!




Pete
N6QW

Friday, January 18, 2019

2019 ~ Piddling in the Shack

What to do when all is does is rain?




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.

73's
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.

73's
Pete N6QW

2019 ~ Building SSB Transceivers

The Building of a SSB Transceiver ~ You can do it! 2/21/2019 ~ Go Daddy Now Fixed! The audio Amp Schematic is on the website. 2/20/20...