Products to be found.

Since 99% of hams literally no longer scratch build anything anymore this causes the: Gee does someone make a kit for such and such application. Kit building gives you the feel of being a real ham and not just an appliance operator. Kit building while also is a Flash the Cash is less of the unboxing a completed unit from "Chine" and more of a pseudo feel of I built this.

Antenna tuners are a good example and there are a couple of companies that sell fully automatic high power antenna tuners, and many have a hefty Flash the Cash price tag. But what if you wanted a kit as this suggests having the capability but at a lesser price. So, we consulted the House of Bozos (BoJack + Bezos) and found a plethora of low-cost 100-watt automatic and a bevy of kits (mostly QRP) but some rated at 100-watts where the Flash The Cash < $100. 


Now if you are in the 1% who wants to homebrew a 3KW automatic unit then you could do it with stepper motors and Arduino code.




So, now you know where to find Automatic Antenna Tuners assembled for less than $100 or basic kits for under $50. That $35 kit just gets you in the door, but to see the fan dancer you need to spend additional $$$ for connectors, a case, a power supply and likely now beyond $100. But you get the extreme satisfaction of saying: "Look Ma, I homebrewed an antenna tuner kit."

Them that know can scratch build a high-power antenna tuner.

73's
Pete N6QW
at

A Practical Problem.

Here is the problem. You are passing by a garage sale and spot a box full of parts and the price tag says $0.50. In the box is a pretty healthy power transformer rated at 250AC CT at 0.130 amps, two 100Ufd filter caps rated at 600 VDC and a 10 Henry choke rated at 150 milliamps.




You could get quite an array of voltage outputs from these components depending on what configuration you use for the rectifiers.

Three possible configurations include:

1. Full wave rectifier (2 Diodes)
2. Full wave bridge rectifier (4 Diodes) choke input
3. Full wave bridge rectifier (4 Diodes) cap input

Drum roll...

Full wave rectifier ~ 175VDC
Full wave bridge rectifier choke input ~ 225VDC
Full wave bridge rectifier cap input ~ 350VDC

That is quite a spread but while the voltage values would seem to draw our attention there are other factors which would actually directly influence your selection. Invariably many would invoke the best looking with the biggest boobs criteria (350 VDC) but fail to look at voltage sag, ripple voltage content and current availability. 

The full wave bridge with a choke input has better voltage regulation (less sag), less ripple voltage at full current versus than the Capacitor input form. So, the highest voltage configuration may not be optimum for your application. This requires you to look beyond the size of the boobs.

Not looked at is another configuration and that is the voltage doubler circuit as found in many Heathkit supplies (HP23). That 250 VAC and two caps can be made to look like 700VDC... but not at full current. 

With an eye toward those who think math the voltages in some of the forms is involved with the number 2, its square root, divided or multiplied.

In the case of the simple full wave rectifier we have the 250 VAC multiplied by 1/(2^.5) = 175 after subtracting the diode junction drops.

The full wave bridge with choke input = 250X.9 = 225. 

The full wave bridge with cap input = 250X1.414 = 350

The Voltage Doubler is 250X2.8 = 700. You can easily see gigantic boobs, terrible voltage sag, high ripple and not full current capability. But it is a cheap way to get high voltage.

So, that 50 cents could be quite a bargain. The only concern is the transformer has a short to ground, the caps are at End of Life, and the choke is open. There are no free lunches. Kind of like what the majority of Americans did last November. 

Our garage sale bargain is but another example of Flash the Cash.

Them that know can make things go.

73's
Pete N6QW
at

The Surprises Coming for Ham Radio! More Flash the Cash.

Our hobby started 1st with Spark Gap transmitters and Coherer Detectors using CW. Fast forward through tubes, transistors, AM, SSB, FM and now Satellite, Digital and of course FT-8.

Something hiding in the bushes is Digital Voice and a new mode FreeDV 2.0 which is digital processing of a SSB signal. Take your standard SSB gear and add the free software FreeDV 2.0 and you are in the mode of pulling your hair out. A snippet from their website...


I saw that there was a demo of this mode as far back as 2018 at a RSGB convention, so this mode has been around for 7 or 8 years. I heard about it yesterday. This Digital Voice Mode is yet another omen of contests and operating overtaking homebrewing anything. Some will read this as an assault on purely hardware defined radios as computers are involved and it is just that. 

My crystal ball suggests this mode will soon be fitted with functionality and software so that your Smart Phone is now a  FreeDV transceiver. All the pieces (or most of) are there, and it just takes someone to link the LEGO Blocks.



FreeDV 2.0 Control Panel

I fired up my Hermes Lite 2.0 and downloaded the free software and got nowhere, but then again, I didn't read the manual. When I hit the PTT button on the screen I could see my transmitted signal on their control panel, so the Hermes Lite 2.0 is being controlled by the Software.

The Bandwidth is less than the 6 kHz often seen with the high end SDR's and supposedly the digitization of the SSB improves the signal in and out. (I am stating to you more than I really actually know.)

It was invented by hams, and the Far East radio manufacturers are financially supporting its development as this will eventually show up as an operating mode on rigs like a future IC7300 MK3. 

This is likely not something you build but takes advantage of already owned rigs and applying open-source free software and this "Good Buddy" results in a new mode of operation. One desirable feature is that you can click a link and automatically see who is on what band and whether they are just listening or actually operating. One watering hole seems to be on 20M at 14.236MHz. 


The above video is a demo of FreeDV on 14.236MHz. It must be in a stealth mode... nothing heard or seen.

Try This One.


I have used the QUISK SDR software for many years and in the last 10 years noted a button on their dashboard marked FreeDV. I never knew what that was.

If you have a plain old SSB transceiver then you will need some sort of interface wiring to the computer and likely a 2nd sound card installed in your computer. For those whose rig is controlled by SDR software some of that wiring exists in the set up for the SDR.

Alert, Alert, there is a Waters and Stanton (a major radio dealer in the UK) you tube video covering the IC7300 MarkII that now has an advertised price and a potential for Christmas delivery. Despite all the improvements and new features like a CW reader, HDMI port and USB C Port and improved hardware, the price point is not a far from a plain, now 9-year-old IC7300. The presenter used great finesse in stating the obvious, with the attractive price of the Mark II, the used market for the original IC7300's will take a downward hit. That affects 100,000 radios as that is the number of IC7300's that have been sold so far.

You better get to know as you will not get to go. 


73's
Pete N6QW


at

Test Instruments costing less than $15. Flash the Cash.

Before starting today's presentation, I would like to acknowledge a think outside of the box, outstanding ham homebrewer and might I add good friend Tony G4WIF. 

Tony is a not a Flash the Cash guy in the sense he is always tries to find a cost-effective way to execute a project. He often looks outside of the traditional ham hardware, read often expensive. In this link Tony presents a vertical antenna project that requires some special standoffs to keep the antenna wire from touching the mast support. Shazam, plastic kitchen cabinet hardware which is cheap and when installed appears like it was custom made for the antenna task. G4WIF employs a Nano VNA to test his antenna which is yet another must reason to visit the LINK 

A great big Thank You to G4WIF for sharing your work. (Regrettably 4 Meters is not authorized in the USA.)


          10 Testers /Accessories< $15

Today I am pleased to present ten test instruments and/or test accessories costing less than $15 each. 

Now the rub, as this moves the user into having to know how to read technical instructions plus have some basic understanding of electronics. The latter of course is no longer mandatory to get an Extra Class license. So, let's Flash the Cash! Search Amazon under Electronic Test Instruments.


Test Leads ~ $8.99

Murphy's Paradox... You are always short one pair of test leads. Either you lost them somewhere or they are broken.


USB Tester ~ $12.34

DVM ~ $9.99


Continuity Tester ~ $7.99


Voltage Presence Tester ~ $8.99



Resistor Capacitor Diode Tester ~ $13.99



Fat Index Tester ~$7.99
Magnetic Pole Tester ~ $11.99 (Guitar Pickup tester)

Panel Meters ~ $9.99 (Five Pack)



DVM #2 ~ $14

These are general purpose instruments usable on items other than homebrew radios built with 2N3904's. But you might have to know stuff to be able to effectively use them.

Again, we are shifting the focus of this blog in response to where the hobby is headed... The Flash The Cash mentality.

Can't wait until we hit the under $1000/item threshold. Man is there some neat stuff out there.

Four Channel Rigol Scope ~ A bargain at $999


There is a cautionary note about one of the list items and that is the low-cost Fat Index Checker @ $7.99. You must avoid use of the device in, around, or in proximity of the XYL and GF. They will think you are sending a hidden message. It is included in the list for the OM's as we enter the fat inducing Holiday Season.

Them that know, Do Know how to Flash the Cash!


73's
Pete N6QW


at

Flash The Cash.

Ten Things for your shack each costing less than $10. Ready to use, no technical content, no detailed need for pre-implementation preparation, no assembly or soldering required and no ham skills that must be acquired. (A perfect set of requirements for meeting the skill set level of a newly minted Extra Class Licensee)


Under the new Flash The Cash template you have to do some of the work. Go to Amazon and type in Electronic Tools and you can find all of these items.

Stripper/Cutter ~ $7.99




Digital Calipers ~ $6.88

Flush Cutter (also good for toenails) ~ $7.76
Tweezer set ~ $5.99

Test Leads ~$5.99


Pry Open Tools ~ $9.99


Mini Pliers ~ $9.49

Soldering Set (For Repairs Only) ~ $9.99


The Third Hand ~ $9.94



While many of the tools appear to cater to the ardent homebrewer, they have general applicability like when you need to open up your Cell Phone, Alexa, Computer, Tablet or Smart Watch. You are covered even when the XYL or girlfriend goobers up the lock on her jewelry box.

[BTW less tax and shipping, the cost for these 10 items is $84.01. Give this list to your XYL, GF or Partner and this could fill your Christmas stocking with usable stuff. Careful don't give the XYL and GF the same list as you'll end up with 2 sets of everything.

Just think that during the Crusades a set of tools like this would have been a boon to the average neighborhood Lothario as an aid in opening locked Chasity Belts. Excellent technology, regrettably just a few centuries too late for our Lothario. Interesting note is that the word Lothario finds it roots from the Italian. Here all along you thought Michaelangelo was just a good painter. ]

Them that know... know how to Flash the Cash.



at

Breathe Easier...

The 2N3904 rig will never happen and this is a result of the reality of the very, very small interest in building anything these days. 

It was a suggested project doomed to failure as using a 2N3904 throughout the rig, results in building in the old way of doing things that we have now replaced with modern technology. 

Who in their right mind would settle for a drifty Analog VFO when you can have a Digital VFO and the BFO comes as a bonus. 

The real negative... no circuit board and no kit. I know it can be done so I have no magic goal to personally be achieved. 

A singular benefit is teaching the very few, the tired and the brave, a process for building a true homebrewed SSB radio using a common device in every active circuit. 

Ten years ago, I along with AI6YR created a close cousin (with the same teaching goal) and it was published in QRP Quarterly under the title LBS standing for Let's Build Something. A few units were built by the ham community, but it never went viral.


So, Blog Readers you dodged an ad nauseum treatise on the Emitter is biased at this point. Lucky you.

If you know, then you really do know when it is time to go. Likely my time is better spent in making unboxing videos on radios and products from "Chine" as history has shown that is what the customer wants. Bottom line simply stated keep out the technical content and emphasize the flash and cash.

73's
Pete N6QW
at

Passing Gas!

Yesterday's blog entry had about as much appeal as passing gas in a church service. Today's posting likely would be a "double dose" that includes not only refried beans but cabbage as a starter mechanism. I go forth well knowing the disdain for today's post.



Link to Doug DeMaw


Yesterday's post suggested the 2N3904 as fulfilling the FOAM template for home built SSB Radios. FOAM of course is Filter, Oscillator, Amplifier and Mixer. 

One area "illuminated for development" was the Driver and Final Stages and how to get more juice out of a combination 2N3904's. One faithful blog reader turned to AI and furnished me a design for a Push Pull Driver stage capable of delivering 250 Milliwatts of RF (10 Volts PTP). It was a pretty simple circuit using FT-37-43 cores on the in and out ports. Thanks Bruce!

In my own thoughts about how to do it I thought of Hybrid Combiners, and this is sort of cool where you could have two or four individual amps and sum their outputs using a bit of Ferrite magic. That search turned up two references (likely out of hundreds) and the 1st is a book by Doug DeMaw, W1FB (SK). 

Doug was a co-author with Wes, W7ZOI of Solid State Design for the Radio Amateur, which I consider as better than EMRFD. Just my opinion. The book in the link reads much like SSDRA and you can download it from the link. 

One subject I covered long ago in this blog was Capacitive Matching in tank circuits. Doug covers this subject with some great lead by example information. There are even some practical circuits using BJT's and FET's with the detail to build them. I had never heard of this book before and undoubtedly, I will get emails to the effect how did you not know.

The second reference is from Helge Granberg, the RF Amp expert from Motorola and his Application Note #749. In a separate App Note Granberg presented a design for a 1KW output ham amplifier using four separate 250-watt amps and using a Hybrid Combiner summed the outputs to yield a 1KW Broad Band amp. He is the man.

Below are two examples of simple Hybrid Combiners from the #749 for two amps and you need to read the note about the 25 Ohm transformation. Another ferrite core on the output can make 25 Ohms look like 50 ohms. A Ferrite core with 10 Turns and 7 Turns will do it as 10^2 = 100 and 7^2 = 49 which giveth 100/49 = 2.04 which is close enough for government work.


BTW I have used circuit 7B in one of my homebrewed SDR transceivers to take the on the air signal from the Band Pass Filter to provide an I and Q input to the pair of ADE-1's. It is this same circuit that works when transmitting to combine the I and Q summed output to the BPF. 

Them that know can make things go!

73's
Pete N6QW
at

The 2N3904, A Magical Device.

Today's Blog posting is a result of an email I received commenting on yesterday's post on introspection. 


I am at this point uncertain whether the input was a tongue in cheek comment (maybe even cheeky) or perhaps a serious input. Essentially it said are we done looking at tubes, transistors, loop antennas and perhaps wean myself from 12AU7's and 2N3904's and focus on where the rigs are headed. You know FPGA's, digital signal processing, pre-distortion, SDR and external audio panels using Sennheiser Microphones.


2N3904 as sold by Jameco Electronics

Shazam, I thought I get it, the input is suggesting I come up with a SSB radio that uses nothing but 2N3904's. Yes, someone has done an all 2N2222 CW transceiver (Jim Kortge, K8IQY) and the PSSST came close with 5 out of 7 transistors using a 2N2222A, but how about a transceiver using nothing but 2N3904's. 

First and foremost, the 2N3904 is a very common device and really cheap. As a reference, the Jameco 100-piece price is $0.06 apiece. Stay away from the Amazon BoJack variety as likely they are duds... I found that out with the IRF510's I bought from Bozos, (BoJack + Bezos).

The 2N3904 could fit the architecture of the P3ST but the real challenge is the Driver Stage and Final Amplifier. These circuits would have to be developed using only a 2N3904. Keep in mind the Bitx 20 used the 2N3904 in the lower-level stages but stopped short in making it all 2N3904's in the rig. Why even the die-hard TIA aficionados could get their 2N3904 day in court. Luckily mostlydiyrf.com sells the TIA as a kit.

The idea of using a single device in all circuits is something I saw in a CQ article where during WWII, the Germans used the same tube everywhere in a simple field radio. Neatly packed in the case was one spare tube... usable in any socket.


The above specs for the 2N3904 define why it would be a good choice for the proposed rig. 

For those with an itch in your shorts, the audio amp would not use the LM386 or LM380N-8. The BFO and VFO would be fabricated using the 2N3904. I likely would use a crystal switched Super VXO rather than fiddle with a drifty VFO. The VXO and BFO would use but four or five 2N3904's.  After all we bought 100 pieces of the 2N3904.

A Sanity Check on expectations. At best the rig could do maybe 1 to 2 watts out and that would come from something other than a single 2N3904. But let's start first with driver stage as that would need to deliver a minimum of 250 milliwatts and an interesting approach might be a push pull driver stage. This would need development. 

I remember seeing in the G-QRP SPRAT where a whole bunch of 2N3904's were paralleled to develop greater than 1 watt output. That again would need development. But that sort of effort is what makes this a worthwhile project. I have worked DX running two watts on SSB.

The only thing left is to distinguish between tongue in cheek and cheeky. 

Tongue in cheek we know is to say something knowing full well it is likely untrue. Mary Jo is svelte. Cheeky is British slang which is close in meaning but pointed with an added twist of being disrespectful or impolite.

There is no question in my mind that it was tongue in cheek. I only mention this because I was once called out for being cheeky for calling a rig a piece of crap. What the person didn't realize is I use the term CRAP as shorthand for Cool Radio And Project.

Them that know can make things go. (That is sort of cheeky)

73's
Pete N6QW
at

A Time for Introspection?

At times it is really good to look inward and ask some of the hard questions. You know, like should I build yet another radio or for many hams do I need to buy another Chinese radio? Maybe what I have is plenty and I should just operate or join contests.

I guess in the land of plenty we have developed an attitude of more and better. The Chinese marketing experts are counting on you to be "unsatisfied". Sadly, it may be more but not necessarily better.

On 40M yesterday I heard two local hams banter about their very high end SDR radios. Each had one but one was a Flex and the other an Apache Anon. They were somewhat arguing "mine is bigger than yours". The argument had as a locus the "pre-distortion" functionality.

I am about to share much more than I really know or understand. But I imagine the pre-distortion feature is to cure a problem. It seems when you do a wide-band SDR signal (3Khz) and pump that through a legal limit amp (for some this is 5KW) what cometh out the other end is not so clean. Supposedly the pre-distortion of the signal, magically makes that signal sound clean. (Again, I do not know of what I speak.)

The primal argument was the Anon guy said his radio had real pre-distortion, but the FLEX had a claim of this function, but it did not exist in the 8000 series he was using. 

So, I guess harkening back to old times how about a 2.5 kHz wide signal with no speech processing, a good quality microphone and a real legal limit amplifier and of course something more than a wire laid out on the garage floor as an antenna.

This prompts yet another introspection: Did what is his name really need to spend hundreds of millions of dollars on a ball room makeover? Explain that to those out of work and about to lose their food stamps. Yes, the answer always is: Mine is really bigger than yours. 

Them that know can make it go.

73's
Pete N6QW
at
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