Thinking Out of the Circuit Board

 A Time Long Ago, Things Were Different.

As a homebrewer (starting back in the early 1950's with a CK722 transistor) I find that today we have lost an important insight into what we do. I didn't; but many have.

Gone is the quest to learn new things and to strike out on our own. Frequent emails to me ask where is the circuit board or send me the Gerber Files. That gives rise to several questions.

1. So why do you need a circuit board and 
2. Why can't you design one yourself?

The same applies to Arduino Sketches and Code. Typically, most rigs are not totally dependent on just one set of software to run the radio. The problem maybe is that to write code, one would really have to know something beyond asking for the circuit board.

I really don't have any special radio skills. But what I do have is some processes to attack problems and processes to approach a new radio project.  I call it noodling and there is a lot of research that I do up front. The last thing I do is to turn on the soldering iron. Thank God for simulation programs like LT Spice.

That simple one transistor microphone amplifier (above) was extensively simulated and that effort has borne fruit by the number of excellent audio reports. I didn't start with a circuit board. I started by looking at a basic amplifier circuit and on from there. One soon learns how the value of the emitter bypass cap impacts the circuit performance. Now that exercise is a part of my knowledge base.

There are those who will fester over why the resistors R6 - R8? They are there to simulate a 10K output pot. So, when you build the circuit, you install a 10K pot and no resistors.  The output taken from the center wiper to the 0.22Uf cap which connects to the relay terminal. 

But as I share the circuit -- the question persists where do I get the circuit board frequently arises? Lew McCoy, Wes Hayward, Jean Sheppard and James Lamb would not even think of circuit boards! Excelsior!

This is what happens when your mind is on circuit boards and not the circuit... you Strike Out!

That has to HURT!

73's

Pete N6QW

 The PSSST is on "hackaday"

https://hackaday.com/2021/11/20/pssst-heres-a-novel-ssb-radio-design-with-only-seven-transistors/

   

Hackaday

Yes! The PSSST has "street creds" as it has been recognized by a well-read blog post. To The Tribes (BITX, TIA, EMRFD, Nano VNA and Facebook groups) it is posted there without having a link to one of your Tribes. OMG, somebody went around the Tribal system of group recognition.

But there is a huge problem with our hobby, and that is how we view things and worst of all what we have become.

So far there are two comments on "hackaday" there may be more by now. I suspicion that the two posters belong to The Tribes (BITX, TIA, EMRFD, Nano VNA or Facebook groups) as this is what they posted.

Later Input as there now are over 6 comments and one in particular has me scratching my head. The commenter denigrated the design as using musty old parts and the PC Board with squares was like doing brain surgery with a rusty spoon. But the clincher was that I did not use an accessible design. I don't know what that means and likely he doesn't either! 

You can do all the software tricks you want and include ports or WiFi to make software changes but even the IC7300 and FTdx101F have some analog devices in the loop to generate RF, amplify it and send it into the ether. Like on the front end are some DBM's with a post mixer amp that has a high intercept point and considered a strong amplifier. 

The Arduino and Si5351 are devices with accessible design features. So, is he a man talking like a man with nothing to say? When you know stuff, you can do stuff. But when you don't know stuff, you can only make stupid comments like accessible design.

One post in essence took to task the project because "it has MORE than 7 transistors" if you count what is inside the Arduino, Si5351 and the LM-380. 

Well counter to that, I can respond by saying let's make it 10 transistors as I substitute a J310 FET VFO (at 5 MHZ) for the LO, another 2N2222A as a 9 MHz BFO and use a TIP32 as an audio amp stage. That is 10 transistors! BUT now there would be the criticism that it did not use the latest technology and the audio is weak!

The second post complained that it is painful to have to listen to a radio without AGC.

Well, this poster likely has never used at Bitx20 or for that matter really sat in front of a PSSST and just listened. True it does not have AGC; but so, do a lot of other radios lack this feature. Mind you it can be added; but just adds a lot more hardware to the project.

None of the negative comments reflected on the Steerable approach, nor that it really only uses 7 discrete devices, yet has a superb frequency readout and a very stable LO. 

What have we become in that the only comments that can be made are negative! They completely overlook that indeed someone not using The Tribes (BITX, ITA, EMRFD, Nano VNA or Facebook groups) has a working radio employing really innovative concepts?

This begs the question "Have these several posters really ever built anything or is their sole goal to find something trivial that can be "festered' upon within their Tribes? Is their goal to denigrate what I consider "true homebrew". OK you guys, let us see your SSB Transceiver designs?

If they are hams, may their coax get shorted!

73's

Pete N6QW

The PSSST ~ A Minimalist Scratch Built SSB Transceiver

 Talk About Jaw Dropping!

https://www.n6qw.com/PSSST_20.html

With only 7 transistors I keep being amazed by the performance of this Jewel! Yes, it is like a Crown Jewel and I regret not using the Steerable IF Module (shown below) in other projects. This will now become a staple of future projects.

[ November 13, 2021. I now think you can do it with SIX (06)  transistors. If we steer the Mic Amp with two more relays, we now can also use it as the Audio Pre-Amp as it is exactly the same circuit. Scroll to the end. So OK the challenge --can we do it with just 5 Transistors?]

Here is what makes this unique and it wasn't until I made a block diagram that I realized the impact of the design.

 

The initial thoughts on this IF Module were that it would be steered between two ADE-1 DBM's depending upon whether it was receiving or transmitting as shown below with the ADE-1's. In Receive, the signal is steered to the input side of the IF Module from the Rx Tx Mixer stage wherein the output side is steered to the (left) ADE-1 which is in the Product Detector mode and on out to the Audio Amp.

Switching over to Transmit the signal from the LEFT ADE-1 is now an DSB signal as that ADE-1 is now in the Balanced Modulator Mode. The output side of the IF Module now a SSB Signal is passed on to the RIGHT ADE-1 where it is mixed with the LO and on to the BPF.

So, what is significant is that the 1st Transistor in the Module is always a Post Mixer Amplifier and the 2nd one a pure RF Amp. The 1st is always seeing the same loading and a clue that the gain levels of the two stages will be different and are. This is where LT Spice enables you to "twiddle" with the parameters and for the whole assembly the gain was optimized. Of concern too was the gain of the stage for receiving and transmitting so that signals being received and transmitted were consistent.

I have extensively documented this project and in hindsight that was a terrible mistake and here is why I should not have done it! Too much documentation perpetuates the loss of creativity.

Many homebrewers and blog readers simply want to have all of the data including schematics, part number lists, Arduino Code, PC Board Layouts, LT Spice Simulations and performance calculation and need I say it URL Links to Source Suppliers. If it were possible, they would want me to build it too. (I have been asked in the past to do that.)

I do appreciate how documentation can help facilitate the construction of a project. But my fear is that thinking that this would encourage potential homebrewers to take the leap it in effect discourages creativity. Building it like Pete may not be the best mousetrap. Certainly, there are a few who may move beyond that but that is the point they are the few and truth be known they would probably make that move regardless.

Help is one thing enabling laziness is another. As I said before give me a schematic and my “fabrication process” kicks in to make the project a reality. An extensive documentation of a single project is not an inherent fabrication process to enable taking on other projects. The documentation of a single project is simply a by-product of the process –not the process itself.

Let me continue on my soapbox. I think in Modules and that is key to my fabrication process. Those who only want spoon feeding have missed the power of the module which is of course chunking a project into manageable pieces. With this process you can test as you go and downstream when you want to try an upgrade you deal with just a module and not destroy a whole radio to make one improvement.

From my perspective the documentation created for the PSSST is spoon feeding how to build it! Removed from that equation is an underlying process with the modular approach. Regrettably extensive documentation does discourage creativity. 

Steerable modules have been used by me for some time which caused me to get hate mail about the use of relays and why not diodes. Diode steering has been used by me but my concern is signal isolation. That said the Steerable IF Module (not just the Filter) is a 1st for me and it works.

There is another pet peeve -- despite the Herculean effort to create and include all details I still get emails --Why do you not connect R8 (50 Ohms) in the hardware but LT Spice shows R8. LT Spice also had a note R8 is a load used in the simulation; but not connected in hardware. I hope that guy gets a short in his coax! Documentation enables Laziness!

73's

Pete N6QW

Meet The PSSST ~ A Scratch Built Minimalist SSB Transceiver

 Meet the PSSST!

Pete's Simple Seven SSB Transceiver

(PSSST)

[A Plug for Jameco Electronics and My Story]

Documented QSO

The PSSST ~ You know when we want to get someone's attention we go "PSSST". Well it also is an acronym abbreviation for "Pete's Simple Seven SSB Transceiver!" Did I get your attention?

I have posted videos of how the receiver portion sounds on crowded bands and hopefully you have been impressed. I was! 

My work involved NO bilateral circuits, NO TIA amps, it has not been published QEX and there are no Facebook groups and neither are there any group.io lurkers to make snarky comments. The band of choice is 20 Meters

The best part there are only 7 transistors in the whole rig. Five of the transistors are 2N2222A's along with one 2N2219A and one IRF510. The power output is 4 watts and I have a confirmed "1st contact" (DX no less to Canada @ 1200 miles). [I now have a RD006HHF1 in the mix versus the IRF510 and have made a half dozen contacts using the PSSST.]

What sets this rig apart from other topologies is the how it is works. There are two circuit modules that are relay steered to have different signal paths depending on whether in Receive or in Transmit.

The 1st module consists of two 2N2222A's and a 9 MHz Crystal Filter. The input and output are steered between two ADE-1's. On one end the ADE-1 is either the Balanced Modulator or the Product Detector. 

In receive the IF Module output is connected to the ADE-1 in the Product Detector Mode. But on Transmit the input of the IF Module is now connected to the same ADE-1 which now is the Balanced Modulator. 

A relay on the 1st ADE-1 connects to the Audio Amp on Receive and to the Microphone Amp on Transmit. In case you are counting all this is done with three SPDT communication relays. 

Shifting to the 2nd ADE-1 on Receive it is the Receiver Mixer and on Transmit it is the Transmit Mixer. At all times the 2nd ADE-1 is connected to the Band Pass Filter. However, the 2nd ADE-1 is either connected to the input side of the IF Module on Receive, or to the output side of the IF Module on Transmit. 

Noteworthy the BFO and LO are always connected to only one ADE-1 and are not switched.

The second "steerable" circuit module is a single 2N2222A that acts as the Receiver RF Amplifier on Receive and as the Transmit Pre-Driver on Transmit. 

Stop! Up to this point only FOUR 2N2222A's are used in Receive (Audio Pre-amp, IF Module and the Rx RF Amp) and FOUR 2n2222A's on Transmit (Microphone Amp, IF Module, and TX Pre-Driver). I would call that Minimalist!

The Audio Amp uses a 2N2222A driving an LM380N-8 for more than room filling volume. The Microphone Amp uses a single 2N2222A. A good deal of time was spent optimizing (LT Spice) the Microphone amp to have lots of low frequency gain, so the sound has lots of "presence". This same circuit is the audio pre-amp. 

Note to those who don't read the print. What connects the Pre-Amp to the LM-380N-8 is the 10K Pot. Read Carefully that R6-R8 are there only for simulation and are replaced with the 10K Pot. Having R6-R8 gives the three plots to simulate a Pot. I have to say this because undoubtedly I will get two emails that say "I don't understand the schematic". Friend learn how to read!

USE ONLY THE TO-18 VERSION OF THE 2N2222A. Because they are being driven hard -- they run hot! 

A lot of effort was spent with circuit simulation and hidden in the blocks are optimized amplifiers and extensive use of circuit matching. I am particularly impressed with the 2N2222A over the 2N3904 for this application as it current limitation is 500 ma (versus 200 ma for the 2n3904) and it can be fitted with a heat sink. 

Now there are those who will go to Google and tell me immediately that the 2N3904 total device dissipation is 625 mw versus the 2N2222A at 500 mw. But it is hard to put one of those cool top hat heat sinks on a 2N3904!

Keep in mind NO BITX, NO TIA and NO QEX. This is not a kit but holds the promise of a minimalist rig goal that sounds really good. I am encouraged by the Pout (4 Watts) on 20 M and think with a different filter (like 10.7 MHz from Spectrum Comms. UK) this can be transported fairly easily to 17M.

I need to dig out my digital adapter and run this up on FT-8 and WSPR --just to quantify how good the hearing part is.

The those who never have built anything; but act as if they know everything about anything must be suffering terribly. Aside from a few block diagrams they have nothing to pounce on with the intent to denigrate. 

In time I will be publishing (note I said publish) detailed circuit, information, LT Spice simulations, and lots of photographs of the fabricated modules. But for right now I am just delighting at having been successful with the PSSST.

A ham yesterday got an email about his homebrew rig from a lurker. The email contained factual errors and it was obvious the person sending the email lacked technical skills and yet spoke with such authority. Thus, before you send me one of those emails, I have the hardware and the data. You now also have the video of a QSO.

It is like the ham who commented on a you tube video I made on the HW-101. He said if he owned one, he would never do what I did. Well friend if you owned one, you would do what I did. The bottom line -- if you haven't built the PSSST -- you can't possibly know!

73's

Pete N6QW

A Scratch Built Minimalist SSB Transceiver

A Minimalist SSB Transceiver?

November 6th Update. 

Listen to the CQ WW CW Contest. Can your radio hold up in a crowded band with lots of strong signals?

****

Now with a Color TFT display! 11/05/21

First Receive and Transmit tests. Very Promising... HD8R is an Expedition to the Galapagos Islands! 11/04/21

Just as there is a difference between a 29A and a 44DD, the replacement homebrew audio amp for the eBay module certainly points the direction and stands out in a crowd. It is superb sounding with the final device being the the LM-380N-8. This will be in the final design.

The 1st Sounds of the Minimalist SSB Transceiver. I held the phone up to the earbuds to make the recording. C Change - The eBay amplifier module is underwhelming in its performance. I will have to sub in one of my homebrew modules. But this is encouraging! It does have a formal name but not a YL's name. 

These days I seem to be reflecting on the past and harken back to 1959 with an analogy. So in 1959 (I was 18) my thoughts about an ideal girlfriend was to think in terms of the minimum requirements for a YL such as could she change the spark plugs and set the timing on a short block Chevy engine. More importantly did she know what needle nose pliers were and did she know how to solder a Western Union splice joint. Yes indeed, those were the minimum requirements.

Short Block Chevy 350 Engine

That is a 57 Chevy -- a Really Hot Car. The Girl looks OK Too ~ Healthy is a good word!

Yes , this is the official  Western Union Wire Splice!

These are not torture devices; but real Needle Nose Pliers

[ I have posted the above photos as many modern hams and many Box Top Extra's (BTE's)) who only use Facebook, would not know of what I speak.]

Likely an 18 year old kid today would have a list including: Is she hot looking, does she have money, does she drive something newer than a 2 year old car? Does she have a posse on Social Media and does she live on the better side of town?

In 60+ years the focus has shifted from skills (wrench turning and soldering) to the external environmental features (looks, money, power)

In today's world regrettably, many hams evaluate a homebrew project based on can it be found in EMRFD, does it have TIA amplifiers, does it have roots in a Bitx topology? Is it SDR based with a Teensy and Nextion touch screen display and has it been showcased on 'hackaday", mentioned in a well known podcast, has a Facebook following  or is published in QEX?  

Failing to meet any of those 2021 environmental criteria, then most of today's hams and certainly BTE's  would move on and not take a second look. Bummer! They have just missed an opportunity to experience building and using a  workable transceiver that performs well and will never see the pages of Facebook!

Unfortunately, Social Media platforms like Facebook have "trained" the modern ham to  think in narrowly defined paths which only run through these environmental aspects. That is so sad!

But suppose, just suppose you could have a design that uses the minimum number of parts with the same device in all sockets and have a working  rig, yet it never saw the light of the aforementioned 2021 Environmental Criteria.

This is a tall order; but suddenly there is now a shift back to skills and tribal knowledge! Thusly knowing stuff, you can do stuff. 

Stop looking --you can't find skills or tribal knowledge in Facebook! Today's QST won't help either unless you are shopping for a $6K transceiver from offshore!

I am taking on  this project adventure to show that you can build a proper SSB Transceiver using some very basic circuit elements. Additionally this is an in your face challenge to those who never build anything; but often speak like experts about everything. 

It does have a name; but is being withheld at this time.  You will just have to keep tuned to this channel to find out. 

In case your wondering --the YL in front of the 57 Chevy was not my girl friend!

Pete, N6QW