The Power of Data.

[I did get the 64-Bit version of the R Pi5 to work with QUISK. No explanation for the initial difficulty. Great signal reports running 3 watts (35V PTP).]

Believe it or not there is power in data and sometimes we ignore that data and the results are not good. Today we will talk about data and why we are misled.

I watch my blog data and find it fascinating that some blog posts simply resonate with the readers while others fall flat on their "arse". So, having data is not an end in itself but it is what you do with the data that really counts.

My recent posts about homebrew SDR are a good example where the viewing is tepid at best and the one about the new zBitx from VU2ESE was highly viewed. Both are SDR yet the disparity in hits is 5 times for the zBitx versus my homebrew SDR radio.

So, time for an analysis as to the why the difference.

The 1st may be a trust issue. Yesterday I was looking for a service on the internet and I immediately passed by anything with a less than 4 out of 5 rating. I simply jumped to the trust issue as a discriminator. One was a 4.5 rating I zeroed in on but then looked closer that was but a single review whereas a 4.1 rating had 800 reviews. 800 reviews offer a more composite rating versus a single review. Which do you trust?

So maybe my work is not trusted as certainly VU2ESE sells literally thousands of commercial units and maybe I have built one or two of the same design. So, I get it that my efforts are purely a single effort and mine is only one report on how good it is. It is human nature to think Pete is looking through "rose colored glasses". 

Then there is the data point of cost as you can have a zBitx on your bench for $178. Building one of my rigs will cost you perhaps a bit more than that as buying parts in small quantities costs more. I also have a huge junk box so my project cost will be different than someone with a small stash of parts.

But the elephant in the room is the technical skill of the builder and that only comes with time and experience. Likely the only things you need to know about getting the zBitx online is to not reverse the power leads, where to connect the antenna and where the microphone plugs in. You will of course have to know how to navigate any menus -- but in time there will be at least 20 You Tube videos to lead you through that effort.

You actually have to know stuff to build my stuff!

In scratch building my rigs I have a lot of tools not found in most ham shacks like a CNC mill and a manual mill and of course some basic test gear like DSO's and signal generators, power supplies and hand tools. Many ham shacks lack even a SWR Bridge.

Not in the data but certainly present in a ghost like manner is the FOF. The Fear Of Failure is a huge deterrent and besides if you build a Pete Rig there is a huge time investment of coming up to speed on the design and understanding that design. Along the way is figuring out how to actually lay out and build the hardware -- that only comes with time and experience.

The "look" is another matter. I shudder when I see an LCD mounted on a front panel where the hole was hacksawed in place -- doesn't everyone have a CNC. Ugly construction is not limited to circuit boards! The zBitx has a nice look whereas some of my work looks like a disorganized bowl of spaghetti. Pasta Pete has many definitions.

I also found if a posting has no photo embed that you are panned. The picture equates to 1000 words and that visual attraction is mandatory. But you simply cannot post pictures of naked women and hope to garner lots of views. Aside from being illegal, pornographic and morally wrong, those photos are not germane to ham homebrew. Comments about the 300-pound Mary Jo in the backseat of a 57 VW are to merely to frame a level of difficulty that may be experienced in ham homebrew.

Without a doubt this posting will get a tepid reception but there is a final point and that is one about human nature. My pointing out that our hobby will become more technical in synchronization with the technology advancements -- this is a stick in the eye to the many licensed hams that are extras and were essentially handed a license by the ARRL. It is a hard morning wake up call to realize that shortcoming. So, the age-old remedy is out of sight is out of mind.

So, my data tells me that I should stay the course and keep posting items that make a significant segment of the readers uncomfortable as that may just be the kick in the pants to drive up the technical skills of those participating in our hobby. While ham radio was the 1st social media vehicle it also started out that you had to have technical skills. There are many venues outside of ham radio where you can connect with social media and all you need to know is how to post items. Let's get back to our technical roots!

Them that know can make it go!

73's

Pete N6QW

Movement Forward. Raspberry Pi5 SDR and Other Electronic News

First things first with a bit of info on the world of other electronic news. Bill, N2CQR and Dean, KK4DAS have hit beyond the mark with their SolderSmoke Direct Conversion Receiver Project as "proof of life" units have been seen around the world. In a biblical sense, they have taught hams how to fish. Bravo guys! 

Every venture has a starting place and their DCR is a great vehicle to begin that journey. With a successful project the quest begins for bigger and better and that opens the door to the universe. (Like may be a HB SDR which is nothing more than two DCR's in Quadrature.)

Well, I now have a Raspberry Pi5 working on the homebrew, SDR transceiver. It was not plug and play and a few hiccups along the way.

Generically the problems were mechanical and software. The RPi5 needs 5.1 VDC at 5 amps which in simple terms means you need a heat sink -- with a fan. 

If you follow the 40-pin header at the top of the RPi5 and just behind the top two USB ports you see a small white socket. Now look at the fan connector mounted on the heat sink -- that jewel plugs into that socket. With the fan/heatsink installed not easy to get tab A installed in slot B especially if you suffer from FFS. On turn on the fan didn't work! But the heatsink alone while warm to slightly hot was good enough to load the software. 

To make a long story short when I installed the plug, I evidently pushed one of the boards pins out of the way and so no contact. The fan has four wires with two to control the voltage and two to regulate the fan speed. Long story but a cascade of events resulted in pulling the board mounted socket off the pads and no easy way to reattach. Then I cut the plug off of the fan and attempted and action similar to the Mary Jo maneuver in the back seat of the 57 VW Beetle. Mostly blind and unable to reach some very critical parts. I was unable to get all four wires soldered to the teeny tiny pads. Next trick --simply supply the voltage pins. I did that off board and 5 Volts made it run. Thus, I was able to hard wire the voltage wires to the pads and it looks like hell but now have fan cooling.

It's Like Mary Jo in the back seat of the 57VW

One Step Up From a DCR

Optimal Shop $15 Sound Card!

Spectrum Display for a portion of 20M

FT-8 QRP using the R Pi 5 and HB SDR

I don't want to seem like sour grapes, but the fan connector is a weak point of the R Pi 5 board.

On to the software. When you load the OS to the SD card you can opt for 32 Bit or 64 Bit. Inherently the RPi 5 is a 64-Bit machine. I started with the 64-Bit OS, but I was unable to get QUISK to work and as the Doors would say was unable to "Light My Fire". Then I tried the 32-Bit OS and that was successful. I cloned that SD Card and later will go back and attempt the 64-Bit OS. It is a good idea to keep a copy of what works.

Some bonus stuff with the RPi 5 -- Netflix and Prime can be watched with no glitches so when the bands are dead you can watch Season 3 of "Reacher". If you have You Tube TV given Netflix and Prime work, that should too. Kind of amazing what you can get for $70.

Them that know can make it go.

73's

Pete N6QW

Person of Interest...

Stop, as there is nothing of radio interest in today's posting. So just click off to another radio blog. But you should read this as what I am posting is just too coincidental to be something other than what is really is happening.

Person of Interest was a five season TV program that aired over 10 years ago. It is currently on Amazon Prime. Thematically a couple of billionaire nerds build a supercomputer that supposedly spies on all things world over and sell it to the US Govt for $1. The premise is KASA (Keep America Safe Again). You can see it now as some departments in the government use it for other purposes. Basically, we are all being surveilled in this show. Essentially it is AI on steroids. With binge watching it will take over 100 hours to watch all five seasons.

Fast forward to today and now one person (Mr. Tesla) can do that same action. No longer are your tax returns kept secret. He can look at them. Mr. Health will now tell you what you can and cannot eat. Education will no longer be standardized as there is no longer a Dept of Education.

What was seemingly a far-fetched TV show about the dangers of AI is now a reality. The important part is this current situation was voted into office by a majority of Americans. So, as you stand in the unemployment line think about Person of Interest and try not to dwell on being redundant or a waste by-product. Take solace -- you did it to yourself if you voted for what's his name.

73's

Pete N6QW

Ham Radio Homebrew has just moved past you!

If you are still homebrewing using analog form factors and through hole components here is but more evidence, you need to move forward to SDR and surface mount. The really big guns and illuminati are already there!

Meet the Tiny 10 from W7PUA, Bob Larkin, a co-author of EMRFD. Out of the depths of the Silicon Forest, W7PUA has created a 10 Band, 10-Watt SDR transceiver which is described here. 

I was put on to this amazing project by a blog reader also named Pete. There is more to the Silicon Forest connection with this rig aside from W7PUA and that is the use of the Teensy 4.1 MCU and SGTL5000 codec from PJRC also located in Oregon.

With absolute due credit to Charlie Morris ZL2CTM, more than five years ago he developed a SDR SSB transceiver using the Teensy 3.5 and the same Codec. I built two versions, and these two devices will indeed generate and decode SSB and CW signals. 

Larkin cites some work in progress, and I did find that on very strong signals you can faintly hear the opposite side band. Likely since the W7PUA version is a later MCU and has some features not found in my earlier version that might not be any concern. That said I did not find any opposite side band being transmitted.

February 2025 HB SDR

Just so you are not confused I have built three homebrew SDR transceivers, all using the same mainboard (Two ADE-1's). Two are of the Charlie Morris topology and one uses a SBC like the Raspberry Pi, ASUS Tinker Board or Atomic Pi.

Do not pooh, pooh the fact that SDR is here and so is Surface Mount! The Tiny 10 is here and if you get any message from W7PUA it is the all band, small size and portability features that drive the high marks for this project. Did I forget to mention how it sounds on receive and transmit. This is a perfect rig for POTA, SOTA and FT-8. BTW he uses "plug in coils" to change bands!

Still want more incentive. Farhan's (VU2ESE) latest two products are SDR the sBitx and zBitx. 

Them that know can make it go!

73's

Pete N6QW

A case for moving on...

I have been dabbling with electronics since the early 1950's, where at age 10, I was struck by the awesome power of a single CK722 germanium transistor. There were those who shouted from the roof tops: these will never replace vacuum tubes. Well, they did.

Throughout my 66 years as a licensed ham since 1959, I was witness to the many changes in our rigs all driven by advancing technologies. Now the move is from analog to digital, from conventional topologies to SDR. While it may be fun to build a crystal set or an all-discrete component analog DCR, the advantages of an SDR are astounding, which of course is mostly software based and less hardware dependent.

Several years ago, I built a homebrew SDR transceiver that at its core is nothing more than a pair of bi-directional Direct Conversion devices operating in quadrature -- even that is a topology from the 1950's only better as the 90-degree phase shift is very stable and precise owning to digital electronics. 

This arrangement was initially controlled with a Raspberry Pi 2 and the QUISK software. That worked nicely. Now I am able to upgrade that SDR rig without touching a single piece of hardware of the rig itself. 

Shortly we will be upgrading to the Raspberry Pi 5 which is 2 to 3 times faster than the RPi 4 and about an order of magnitude better than a RPi 2. The latest QUISK software while not in a league of Thetis, certainly will provide the spectrum, waterfalls and variable bandwidths, all modes including digital and a whole lot more capabilities.

One other plus of SDR is that I have also used the ASUS Tinker Board as a Host as well as the Atomic Pi running Linux Mint20. So, I have many choices and options for controlling the SDR hardware. That even extends to HDMI monitors where I can use a really big monitor or a 7-inch screen.

Stations at the other end are astounded that my QRP signal gets through the pileups and even have to admit -- it sounds great for a homebrew SDR. Give me a break -- it is a great signal!

It is time to move forward and get on the SDR bandwagon. Sure, you can keep your old analog stuff, and it will look great on a shelf. But if you want to follow the IARU convention and just plain operate or work all those contests then the ticket is SDR. POTA, SOTA and FT-8 are a few mice clicks away! 

It is entirely OK to move away from ugly construction, HB DBM's and bits of analog circuits. You will not incur the rath of the Radio Gods. They will be smiling at you for moving on and forward.

HB 5W SDR with ASUS Tinker Board and Optimal Shop Sound Card

QUISK has the ability to record and play back the signal at the other end. So, when you tell the other station you sound like crap -- you can retransmit the recording to prove it. You would find that hard to do with many analog rigs.

So, where to start your transition to SDR. There are many groups undertaking a build of an SDR radio. You can also visit www.n6qwradiogenius.us. You Tube abounds with many videos, and I just saw a neat SDR receiver project called the Pi Pico that a friend put me on to. 

Them that know can make it go!

BTW, Mr. Tesla is coming after your job if you work in the US government, so no one is safe or immune. Gosh will he try to fire old what's his name? Your Fired is no longer just reality TV! 

Those who voted for all this chaos, Cognitive Dissonance is at your office door. It will be instructive to see what happens to the future inflation rates and the unemployment statistics -- will you be one of those chosen as redundant or merely considered as a waste by-product?

73's

Pete N6QW

Manpower Management 101

 I try not to watch or listen to the news as quite frankly it's not good for my blood pressure. 

Lost in the translation are some basic human behaviors that govern how employees react or perform in a job. Threatening or intimidating employees is a sure-fire recipe for the informal organization to strike back. You all know the tricks where the hot request is put on the bottom of the pile, or a small piece of information is omitted that delays an action. Many jobs are poorly designed from the outset and the employee is just following a deliberate written process.

I had a front row seat in such an event. In the late 1960's I started working for the McDonnell Douglas Corporation on the DC-10 program at Long Beach. I worked in the facilities organization supporting the Engineering Labs. Prior to this job I did the same sort of task at Boeing on the 747 program. 

It was an exciting job as my first task was to put together a huge buy package of hardware needed to support the engineering test program associated with the certification of the DC-10. My job was to create a support documentation package for every item that was capital equipment (at that time anything over $200). My instructions were to create a package for each item that included the item description, a photograph, a justification of why it was needed and an evaluation of alternates and of course the pricing (low bid). The package was known as an AFE (authority for expenditure).

This took me a month to assemble working 7 days a week. The bonus was I got to make the trip to St, Louis with the team who would present the package to James S. McDonell himself. The final package totaling millions of dollars fit into two briefcases. I reasoned I went along because someone had to schlep the two briefcases. 

When we arrived at the world headquarters, the team (less me) went off to meet the big guys and I was funneled off to "Harold" who would 1st review the package and insure it met their standards. Harold had a very small office that when he and I were in there it was semi-claustrophobic. It was an amazing experience to see Harold at work. His process was to remove the top sheet (AFE) and collect the remaining documents and neatly place post it notes on the remainder identifying the connection to the AFE. This process took him almost an hour. 

I of course asked why the separation as I was told Mr. Mac (James S McDonnell) read every detail. Harold said he never looks at that crap and once it gets here the only scrutiny might be a question about a single item that cost $100K. It was assumed that Harold was the final filter but now I knew he was just a paper shuffler. 

My boss did have me attend that final meeting with Mr. Mac as I was the single person in the room who really knew what was in the list. I was also cautioned to not speak to or directly look at Mr. Mac. The only questions that were asked: Does this do the job and is this full ask.

Now if Mr. Tesla asked me to explain my job or get fired, I would have to answer that my job was to create paper that no upper management looked at and was merely there for show. Guess we know what would happen to me. We did get the full authorization, but it was an important lesson for me. No one asked just what the St Louis process was -- my boss told me what he wanted in every package, and I complied. He was guessing!

As brilliant as the two-billionaire genius's purport to be, are they really that smart. Slash and burn works in the very short run but in time it fails. We already see critical employees were simply fired without understanding their real jobs. Food safety and nuclear weapons tracking are no brainers.

I saw some interesting applications of US Aid to foreign countries. In 1965 when I was in South Vietnam the aid agency supplied gasoline powered water pumps to small villages to provide a source of clean drinking water. In short order the wells were turned into carwashes and hooker hangs out. A lot of military vehicle drivers would get the mud washed off their deuce and a half truck while enjoying a short sojourn with the ladies of the night who also worked the day shift. The advertising signs were pure entrepreneur and read: Washie your Motah car, Quick, Clean, Safe and Sure!

The above radio is a Xiegu 6100, and I had a chance to work a station running this QRP radio yesterday. It was real DX on 20M (about 500 feet way). I have a neighbor who is a ham, and he got one of these jewels. He was testing out a new station configuration -- bicycle mobile. Yes, he fitted this station on to the bicycle handlebars and the whip, a ham stick was fitted behind the seat on a small platform. It sounded great and with summer coming he is looking for a twofer with ham radio and a cardio workout. This radio can be found for under $500. This would be on a consider list for me if I was looking at a functional portable rig.

Them that know can make it go!

73's

Pete N6QW

Send Me the Code!

My time is limited these days as I write this at 4AM. I often get emails, and I really try hard to be responsive for requests for information.

In one email I received yesterday, the text read " Send me the code and the schematics." Nothing more and no other clues. I sent a blistering response to the effect that while I have successfully built over 55 different SSB Transceivers one thing I have not mastered was mind reading.

Often these requests come from offshore with English being a second language. But that is no excuse for not adding just a few more words like P3ST or the MC1496 DCR. 

I also suspect this individual is a "wannabe homebrewer" with little skill in building a SSB transceiver. He thinks having the code and full schematic will make up for the deficit of actually knowing how to fabricate an SSB transceiver. In many ways it is rocket science to put a rig together and have it move beyond well it kind of works. BTW I don't do full schematics as everything I build is done with modules.

In the future I will not respond to such emails. It is a waste of my precious time! So, if you author an email saying send me the code without further explanation -- It goes in the trash!

Deal of the day! About $70 from Lauren Sanchez's boyfriend gets you the 4GB RAM Model. 

Raspberry Pi 5 SBC.

For about another $20-30 get the special heatsink and the 5.1 VDC 5-amp wall wart.

If you ever move from analogue ancient technology rigs and build a homebrew SDR this is a perfect jewel to host the QUISK software from N2ADR. If you own a Hermes LITE 2, this is a perfect host machine.

My Current radio is a Hermes Lite 2 (remote about 100 feet away) + RPi4

Them that know can make it go.

73's

Pete N6QW

The zBitx. A new offering from VU2ESE

 The zBitx, a 5-watt QRP all band SSB / CW transceiver can be had for $178 including Shipping and PayPal fees. Since it comes from India, it may have escaped what's his name terrible tariff.

The zBitx is fully built and tested and is battery operated and the bonus is that it uses the same software suite as its big brother, the sBitx. For those who are uncertain about software downloads it comes pre-loaded with FT-8, FlDigi plus a host of other apps and advertised that it shines like a beacon on CW. Being battery operated it is a bonus for the POTA, SOTA gang.

Size: 156mm x 80mm x 35mm (including the battery case)
Weight: 415 grams including two LiPo batteries
Display: 480×320 resistive touch screen display with an independent Raspberry Pico front panel controller.
Software: Fully open sourced and available on https://github.com/afarhan
Hardware: Hybrid superhet, open source circuit with full description
Frequency Coverage: All international ham bands from 80M to 10M
Power: 5 watts on all bands except reduced power on 15M, 12M and 10M bands.
Power Supply: 6V to 9V.
Receive Current consumption: 300 mA
Transmit Current consumption: 1.5 to 3A (depending on the Drive settings)
Modes: USB/LSB/AM/CW/CW-Reverse/FT8/Digital modes (with FlDigi)
Preloaded Apps: FreeDV, QSSTV, Fldigi and more are coming

According to the website shipping is slated for February 2025.

At this price point, fully built and tested and is both SSB/CW you would wonder why fool around building a marginal single band homebrew rig. VU2ESE's products are well known and grace many ham shacks worldwide.

73's

Pete N6QW

Cognitive Dissonance

 

Signs of Cognitive Dissonance

Everyone experiences cognitive dissonance to some degree but that doesn't mean that it is always easy to recognize. Some signs that what you are feeling might be related to dissonance include:

• Feeling uncomfortable before doing something or making a decision
• Trying to justify or rationalize a decision you've made or action you have taken
• Feeling embarrassed or ashamed about something you've done and trying to hide your actions from other people
• Experiencing guilt or regret about something you've done in the past
• Doing things because of social pressure or a fear of missing out (FOMO), even if it wasn't something you wanted to do

CD is also known as "after buyer blues". You bought that new Chinese appliance box only to find out you have Spurs and RF Feedback in spades,

But more folks are suffering from CD these days not because of radios bought, but because of who they voted for in the last election. What, you are concerned your Social Security check might stop because of that Tesla guy?

What were you thinking when you bought that Chinese radio and pulled the lever for what's his name. You mean you didn't know? So now all you have is rationalizing the decision you made.

Them that know don't buy Chinese radios nor Tesla's.

73's

Pete N6QW

Free Download of SSDRA

https://archive.org/details/SolidStateDesignForTheRadioAmateur1986/page/n3/mode/2up

February 9th, 2025. If I were to start a Podcast.

False Alarm! I am not about to start a Podcast so let that be known. I also will not be a regular contributor on any podcast.

On a recent shift at the XYL's Board and Care home, as she was napping, and I was sitting beside her I thought about the substance of a starting a new podcast. Much like a new homebrewer how do you even start such an adventure

My formal training in marketing suddenly kicked in by asking what the market segment is. The classic marketing approach considers the 4P's: Product, Price, Promotion and Place.

To be successful in marketing a product, each of the 4P's needs some "beef on the bone". A Marketers pitfall is to use his personal likes to answer the 4P's -- but the marketer's personal views don't count. It's the market segment who sets the stage for the 4P's.

The first question so you can "beef up" the Product aspect, you must ask what do hams do? According to the IARU hams do operating and contests. (No mention of building stuff.) We see how close that answer is to the real world when you think of POTA, SOTA, a contest every weekend and of course FT-8. With the ARRL sponsored dumb down the license requirements the technical aspect has dried up as has the absolute need to know CW.

In looking back over the last 60 years you can see the waves where hams built their rigs and then the solid state and SSB era where store bought was the norm. Curiously there was a period during that same time when the focus shifted to building big RF Power amps -- even Doug DeMaw has a Pair of Shoes design in the ARRL Sideband Handbook. Now all of this stuff (totally solid state) is commercially available and somewhat spendy. 

So, a demographic is developing that describes the target market: contests, operating, solid state, software awareness and little technical skills and maybe no CW skills but also an extra class license and possibly has $$$ to spend.

My gassing about a combo Vacuum Tube/Solid State SSB transceiver is a Pete Pet Project (P^3) and nothing more. Mention it once in a podcast to our demographic and you get a polite yawn -- keep talking about it in follow on podcasts and you lost the critical audience. I can see that in my blog readership in what gets a lot of hits and what is panned. 

Tubes are of the past and even now extensive solid-state hardware is replaced by a small amount of hardware and lots of software. Hardware technical skills amongst US hams as was mentioned is the exception rather than the rule and the pure hardware rooted hams are on the decline or SK's. Yet many newer hams and brand-new hams have software skills. A definite substantial sub-set of the US hams feel right at home with programming devices and writing simple code. Afterall, many had to program their Baofeng UV-35R's.

Then there is a division by number of years licensed. If you have been licensed for 30 years or less, then LC VFO's are not on the radar. If you have been licensed for more than 45 years, then LC VFO's are a basic staple. Hams have their comfort zone and much of that is driven by the year one is licensed. 

I had some first-hand experience about what a market wants, and it was purely accidental. In the November 1985 issue of Ham Radio, there was an exciting 75M SS SSB transceiver project from K1BQT. The heart of this radio was several MC1496 DBM's. A couple of years ago I found my lost bag of MC1496 DBM's and that was all it took to think about building the K1BQT transceiver. Some of the 20 or so devices in the bag obviously had been plugged into a socket (bent pins) while others were NIB.

My long experience in homebrewing said you better test those to see which ones work and which ones should be scrapped. I needed to build a device to test my bag of chips. Looking at the MC1496 datasheet I thought about a product detector test bed and using that as a DCR. I had an audio amp and a Band Pass Filter, and I had been wanting to try my hand at a PNP RF amp stage. I also had an Arduino Uno and Si5351 available. An afternoon's worth of work and I had a working test bed and the by-product a DCR. It was not just working -- it was amazing. It had a digital LO enabling the use on the higher bands all capped with a cool Blue 16X2 LCD.

It was then I thought about writing an article for the G-QRP SPRAT, which I did. The article was well received, and I had over 200 requests for the Arduino Sketch. Accidently I sold the sizzle and not the steak. Many request emails started by saying I don't know much about the Arduino, but this is my chance. Many requesters watched the videos and were hooked. 

I also had a big boost from two UK hams (Tony and Nick) who built the project and validated the "how good" it was, and they created webpages to assist other builders. They also ably assisted hams in the UK who wanted to dip their toe in the Arduino Pond. 

The message here is that hams licensed less than 30 years ago who want to homebrew also want to dabble with the newer technologies. Certainly, you can build a DCR without digital electronics. But adding an Arduino is a twofer and qualifies as a Double D. (DCR + Digital.)

Thus, my marketing voice says if you want to have the market segment of newer hams follow your new podcast then you need to talk Arduino or Seed Xiao RP2040 which also fits in the wheelhouse of hams who got a ticket back as far as the 1990's and want to test drive the new stuff. 1960's - 1980's technology certainly has an appeal but is somewhat dated, and realistically that market segment is certainly much smaller.

We haven't even talked about the Gorilla in the room and that is SDR. Most of the new radio appliance boxes are SDR and it is inescapable that what a ham sees and does with his store-bought rig carries over to what he may want to do at the bench. Going from an ICOM IC7300 to a Regen Receiver is likely a non-starter for the target market segment. But actually, homebrewing a simple SDR rig lights up the radar.

With a podcast (sans a Patreon Ponzi scheme) the content is free, so the Price is right. The Place is the Internet (You Tube, Zoom, SKYPE and Tik Tok) and the tricky part is Promotion and that is where X, LinkedIn and other social media platforms do the work for you.

My marketing meanderings also turned up it would be hard to carry on a hypothetical podcast on a solo basis and to keep it from being in a rut, it is clear that guest participation is key. A segment with well-known POTA guys would certainly attract a crowd as would those who actually designed and built a Digital VFO. Undoubtedly a new and simple SDR design from someone who has actually done it would be huge. Easy SMD techniques covered by a guest would certainly address the parts that are now available only in an SMD Version.

So, my back of the envelope market study suggests that a futuristic podcast should delve into Digital Stuff, SDR, SMD and projects that have software (for updating features) and as a bonus the frequent guest expert. Our hobby is continuously evolving, and the crowd follows the technology. 

You only need to look how many ICOM IC7300's have been sold, and that is a piece of the proof of the changed hobby. The current estimate is 100000 worldwide sales with 50000 sold in the US. That says 1 out of every 16 US hams own a 7300. But if we only look at US hams with HF authorization that is 1 in 8 hams. I did not look at the Yaesu or Kenwood data, but that ratio would only grow to 1 in 5 or maybe 1 in 4 US Hams have an embedded SDR radio in their rigs.

Them that know can make it go.

73's

Pete N6QW

February 8, 2025. Beating a Dead Horse & Obscure DBM's

The idiom "beating a dead horse" is a common term across the world but what does it mean?

A trip to the internet suggests the following explanation: To waste an effort on something when there is no chance of success.

Those who are Democrats should internalize that phrase and rethink the next four years. That guy has you by the cojones and there is no letting go. The chaos and path of destruction is just starting! Don't get mad but get even by playing smart and laying a foundation for the 2026 and 2028 elections. This approach bypasses trying to do a tit for tat on a daily basis. Besides by being silent and in a stealth mode will raise his paranoia level about the hidden state.

For those with bravado and large cojones who think simply buying four crystals and a handful of 68pF caps and hoping by simply connecting those parts will result in a superb four pole filter you are beating a dead horse.

What exemplifies not beating the dead horse is getting smart and that entails learning. Do some research and get a copy of Solid State Design for the Radio Amateur (SSDRA). This book is chock full of learning!

This publication is far more user friendly and useful than EMRFD for a new homebrewer. A tour through the appendix shows you how to hand calculate a Band Pass Filter. Now that sure is handy. It is chock full of projects covering receivers, transmitters and transceivers. There is a great section on practical homebrew test gear which is low cost and easy to build. It would be my recommendation, if I was charged with only recommending one publication. It is really written to include someone with entry level skills. Regrettably EMRFD is not!

Choosing to go with EMRFD as the only one is like beating a dead horse. 

It is an observation of mine that experienced homebrewers always seem to cite their material source as occurred this morning with an email I received. Reference was made to the work of Todd (The Popcorn Blogger, [Vasily]) and Alan who has a prolific stable of you tube videos. Often you will hear Wes, Farhan or Doug as the source. Mere mention of all of these names creates an air of credibility to the subject being discussed. Without question all of these names are the illuminati of the hobby, and they certainly know their potatoes.

This next part to be discussed was in a schematic from Wes in SSDRA for a double balanced frequency mixer circuit that uses the SN56514. So, this next piece is Wes + SSDRA, thus it must be creditable. That particular DBM IC has a changed part number and that is now TL442C. Now that is not a household name but even shows up in a piece of Ten Tec gear.

The TL442C specs are not as tight as the MC1496, but the advantage with both IC's is no cores to wind or diodes to match. Regrettably trying to find a TL442C to tinker with is like beating a dead horse. Homebrewing a DBM is like beating a dead horse when you especially have superb tools such as the ADE-1 or MC1496. I personally am more interested in performance. 

Them that know can make it go!

BTW SSDRA COSTS MORE TO BUY TODAY, THAN EMFRD AND HAS A HIGHER RATING LIKE 4.8 VERSUS 4.5. That tells the tale!

73's 

Pete N6QW

February 6, 2025. Homebrew, homebuilt, and home fabricated.

In the last SolderSmoke Podcast I participated in the subject of Homebrew Versus Kits was covered. One aspect discussed in that session was the totally built homebrew everything. Certainly, to be able to say ALL homebrew would be a high-water mark.

However, there is a huge chasm between something barely working to something that comes close to a commercial element built on a production line. Homebrew elements like LC VFO's, DBM's and Crystal Filters fall in this chasm. 

A seasoned homebrew veteran has no qualms about saying homebrew the LC VFO, the DBM and the Crystal Filter. This veteran says DON'T given that this may be a first venture into homebrewing and the first time building something more than a Michigan Mighty Mite.

Now, to defend my position on those elements and along the way I will provide a solution to those new to the art. Creating that huge gap is tribal knowledge. 

The Double Balanced Mixer is first up and remember I don't use Single Balanced Mixers. In a homebrew DBM the parts are sparse consisting of two cores and four diodes. Each core consists of three windings. Hey, what could be simpler? A lot is going on with those components and not so simple unless you know some things going in (Tribal Knowledge). 

As it turns out how you physically build the DBM and what components you use drives a good DBM versus one that sort of works.

Cores are a starting place. One ham had no ferrite cores and popped in a couple of powdered iron units and his DBM sucked! A good basic starting place is to use the FT-37-43 Ferrite Core. 

The next question is how many turns to use? That is a question driven by the frequency of operation. As a starting place 10 to 13 turns per winding will get you there with the 13 turns to cover the lower frequencies. 

The next issue is how you wind the wire on the cores. Start by using three different colors of wire and twisting the wires to 8 twists per inch. The winding on the core itself must be spaced evenly around the cores. The whole thrust of different colors is to track the phasing of the wires and the twisting and "even spacing" is to assure a coefficient of coupling approaching 1.

I created three you tube videos on how to build a DBM and you can see the how it is done. The above video is part 2 of 3. The videos even show how to add a "balance pot" and how to use that feature to unbalance the DBM for tune up purposes.

The next performance degrader is the choice of diodes and are they matched. Some hams will suggest you don't need to match the diodes -- well if you want the maximum performance you do. The videos were created for the LBS project and used the readily available 1N914 -- if you want max performance use Schottky diodes!

Short leads and tight spacing between the components are another success factor. I actually found a way to lay out the diodes that are a ring, but don't look like a ring but keeps the leads short. 

For a 1st time builder this is more than wind a couple of turns on a core and slap in a bunch of diodes. This suggests buying a couple of ADE-1's and the second unit you build can have the high school science project DBM.

Crystal Filters are the next subject area where you can get really wrapped up in your underwear. Building a high-quality filter is difficult if you have never built one. Difficult in the sense of having a great filter versus it sort of works. 

There are a couple of basic parts to a filter that determine the final result. These include the Crystals themselves and how close the frequencies are to each other, the stability of the crystals in PPM, the number of crystals used in the filter, the coupling capacitors and the matching networks.

The coupling capacitors determine the bandwidth with larger values inversely affecting the width. The number of crystals affects the skirts (bottom width) and the matching transformers the ripple. It is only here that we want the ripple to look like a pair of 29A's and not 44DD's.

There is a rigorous process to determine certain parameters that when popped into software will give you capacitor values and impedances for the matching. Often a homebrewer new to building crystal filters skips over the small steps and the filter sounds like crap. Buy a filter for the 1st project and then you can play science project on the second rig you build.

Next is the LC VFO. A ham recently created a totally homebrew DSB transceiver using an LC VFO. He was excited by his 1st contact using DSB and low power only to be told your signal sounds good -- but you are drifting all over the place. Building a stable LC VFO entails a lot of tribal knowledge including the components you use, the physical layout, the physical construction including shielding for RF and temperature and in the end, you are limited to a single VFO range that often is in the range below 10MHz. 

True there are some tricks like using a higher frequency crystal filter with a low range VFO, but you also have to carefully study the spurs that get generated. The LC VFO inherently is limiting in a single conversion design. So again, build a Digital VFO for the 1st outing and then you can try your hand at LC VFO's if only to say I have built an LC VFO.

Immediately you ask where I can buy the DBM, Crystal Filter and Digi VFO. You are in luck as not only can you buy these parts at one place but they come mounted to circuit boards so they can be easily interfaced into your build. Check https://www.mostlydiyrf.com  Todd K7TFC has the goods where you can buy Mounted ADE-1's, the 8 Pole QER Filter and a Digi-VFO. 

There is nothing like a bad experience to cause one to change hobbies like from ham radio to stamp collecting. Being a new homebrewer and attempting to build stable LC VFO's, Crystal Filters and DBM's that will result in a good sounding station is on par with winning a 3 Billion dollar lottery. Possible but not likely. So, to have a great 1st experience think home fabricated with a goal of totally an all-homebrew rig.

Them that know can make it go.

73's

Pete N6QW