Another 4th of July is upon us. Hey Sam, put the Flag right side up!
I am happy to report that the Drake PTO (yesterday's post) is cranking out RF and so that soon may be tried with one of my homebrew rigs. I did replace both transistors and now a bit of lubrication on the gears will make everything as slick as a baby's butt.
Just a bit of reflection on the importance of this day AKA Independence Day. It is not just a day where there is a good excuse to drink beer at noon or to demonstrate your skill at pitching horseshoes, but certainly a lot more than those typical activities.
It marks the birth of our nation and the high cost to maintain this democracy. Do not take this day for granted. Think of our US Service personnel who around the world are protecting our freedom. Amen brother!
Last night about 8PM local I worked 3D2USU on 20M FT-8 using my homebrew SDR running off of a Raspberry Pi4. I had to look it up as the 3D2 prefix is the Fiji Islands. Of note this station has an eye popping 1,179,504 lookups in QRZ.com.
Speaking of the Raspberry Pi 4, it was more difficult to get working with QUISK (SDR Software) than the Pi3B. A bit of a "kludge" on how I did it but I did find a way. I also have the HB SDR working on an ASUS Tinker Board and an Atomic Pi running Linux Mint 20.
Homebrew SDR
Final word -- today is also a good day to turn off the radios and just spend some quality time with the family.
Often the opener, I never thought was followed by "that the car could go that fast as you get a ticket", or "that the gun was loaded" or "that she would end up pregnant". Well, that phrase also covers today's bit of blabber.
The set up ~ Both Collins and Drake used PTOs in their radios which were hallmarked by a linear readout and excellent stability after a warmup. Collins in the rigs prior to the KWM-380 were all vacuum tube and Drake started with tubes and then went to Solid State.
My "I never thought is followed by that they did that this way" involves a Drake PTO. While rummaging around one of my junk stashes, I found a box marked Drake PTO. I seem to recall having to repair a Drake PTO and that was by installing a replacement PTO as the rig I bought had an inoperative unit.
Given my current mode of operation of trying to fix things, it was time for this PTO. There was no info in the box about what was wrong with the PTO and likely what I did was replace the unit without trying to fix the original one.
In all honesty, likely I said to myself, self you would be treading in very deep water trying to fix this PTO and took the easiest path.
Above and below are some shots of the Drake (R4A) PTO. Somewhat aghast that Drake used cheap circuit board material and that the board was not more rigidly affixed to the assembly. Well, I guess it worked.
BUT what really jumped out was the staggered pitched winding of the inductor. Before commenting more on this, the PTO (permeability tuned oscillator) consists of a fixed inductor whose inductance value is changed by inserting a gear driven powdered iron core through the windings -- id est, no variable capacitor. Back to the physical winding, the stepped pitch makes the inductor act in a linear fashion. Were it a constant winding the change in inductance would not be linear.
All roads lead to Rome and all analysis starts with a schematic. The first problem -- there are so many schematics for the Drake R4 radios. The R4 series includes ones with 13 tubes, 11 tubes and 10 tubes. The latter rigs were a hybrid mix as more solid-state circuits were included like the PTO and Audio stages. There were even two different solid-state PTOs with one a bipolar device (2N706) followed by one a JFET (2N5990).
This specific PTO had the 2N706.
Q2 (2N706) is the Oscillator and Q3 (2N3563) is the Buffer. Notice anything of interest with Q2 having a Cap (10nF) to Ground. So, if I want to test this PTO where do I connect 12VDC?
We now have the old what I see in the schematic is not what is in the hardware. R85 is a 4.75K Ohm resistor at 5 watts and that connects to an OB2 Voltage regulator which is a gas fired 108VDC regulator tube --- if R85 fails you sure smoked a 2N706. With the R85 dropping resistor you get a regulated 12 or so volts into the PTO.
But wait in this PTO the lead going to R85 appears to be encased in shrink tubing and tucked away. What does follow is that a wire is installed at the junction of R85, R104 and R54 and the diode and connects to something in a radio.
This PTO likely came from later production models whereadditional solid-state devices were present and other provisions made for supplying low DC voltage. Thus, what you see in a schematic is not always in the hardware.
Hooking 12VDC to the wire produced no output. Next steps, pull the 2N706.
So why am I doing this? Well, the first part is playing detective, and the second is I might succumb to using an analog PTO in a radio. Despite its flimsy looks the Drake gear mechanism is pretty solid.
Thanks for traveling along -- tomorrow is the 4th of July and don't forget what that stands for -- fly your flag and remember the flag etiquette. Never upside-down Sam, the proper flying hours and it must never touch the ground!
Mention Atlas Radio and immediately you think of Herb Johnson who also was the creative genius behind Swan Engineering later Swan Radio.
Atlas 180
I often wondered if the name Atlas was chosen because of the comic books ads that featured Charles Atlas. Charlie who decried that he was a puny kid used his exercise regimen to become a body builder. He is quoted as saying give me a place to stand and I can lift the world. The Atlas Radio logo appears to have a world globe cleverly hidden in the graphic.
I was an early purchaser of the Atlas 180 and installed it in my Chevy Vega. My one-way trip to work using the California freeways was about 30 minutes so enough time for a few QSO's.
One of my best ever QSO's was with a friend and fellow employee of Douglas Aircraft. My friend Dan was a pilot and for about a 2-year period was a FAA designee qualifying Japanese Pilots (JAL) to fly the DC-10. He would crank up the Collins 618T on board the DC-10 during a check flight over Japan and would look for me on my way to work. Now this was like Applebee's: Some really good eating in the neighborhood.
While its specs touted SSB and CW -- the CW was ok for a rare QSO, but the manual switch over would render it useless in a contest. The Atlas 180 tuned 160 through 20M. All-important a linear dial scale and a reasonably stable analog VFO. For operation on various bands the VFO was shifted in Frequency with no crystal mixing. The IF was at 5 MHz.
The Atlas 180 circuitry was unique having some roots back to a military radio the RT505. Les Earnshaw ex ZL1AAX had a hand in the design of both the RT505 and the Atlas 180. I say unique as there is no RF amplifier stage to be subjected to overload.
Like many in our hobby I got an itch to upgrade to the Atlas 210X (5 Bands) and away went the Atlas 180. That was a mistake! A couple of years ago I found this unit on eBay for $100.
It was a compact radio and I think all versions 180, 215, 210 and 210X had a run of over 14000 units. Icom and Yaesu essentially put Atlas out of business with radios costing the same or less but with 10X the features.
At one time I had a very nice two-hour conversation with Herb Johnson, and he shared that the Japanese Manufacturers were selling (dumping more like it) radios on the market a cost less than just the parts of an Atlas Radio. That will put you out of business real quick.
Yesterday while doing my shift at the Board and Care I thought about that subject. If you are new to the hobby likely the answer is a radio currently being sold through one of the popular suppliers (DX Engineering, Gigaparts, Amazon).
If you been at this hobby for some time, the answer is often something you no longer own. It is with lament that you hear: "I really loved that FT-101B" and I regret ever selling it. Or perhaps your shack had one of these.
A Hygain 3750.
Atlas 350XL
Hallicrafters FPM 200
Astro 102BX
Likely the above radios are not well known to the average 1/2 the total US Ham population (those who can work HF). The offerings were aimed at a niche market but at the time touted as having the latest technology, but often priced like a King's ransom. Frequently the production runs were small in numbers. The Collins KWM-1 line only produced 1250 units.
What was so good about these specific radios? Yes, they did have sizzle with the displays or that if you owned one you would be considered in today's terms -- an influencer. In reality it was all in the marketing. They also had some quirks that were dismissed as "nothing".
I am no different than most hams although I do practice TYGNYB. I own too many radios and I too lament that I should have not parted ways with a specific radio or rig.
During recent months I have cycled through some of those radios and have come to a stark realization that each new generation of radio or rig perhaps solves an old problem while likely adding new issues.
I have no patience for drifting radios and therefore do not build analog VFO's. Yet some of my homebrew SDR rigs are good enough to detect when my neighbor flushes his toilet. Still working on that problem...
It is also a matter of never being satisfied with what we have and are always chasing the bright new shiny penny. This is where you should never be the 1st to buy a new radio offering.
I sold some radios to buy a Ten Tec Pegasus (computer-controlled radio). It went back to TT two times in the first six months, and it was Clunky to operate but I was one of the first to own one. I traded it back to TT for an Omni VI Option 3. Still own that jewel.
Perhaps some or one of the best radios often are simple in design and easy to operate with one hand. They may lack in all of the frills such as the RIT offset control in an SBE-34 that actually caused you to never be in sync with transmit and receive but its predecessor the SBE-33 had no RIT but always was in sync.
Just because a radio could spew out 200 plus watts (Swan 500) does not necessarily mean the sideband suppression was that good. Foiled again by touted power output and not signal quality.
Some radios are impressive in the sheer numbers sold and still in use. The Yaesu FT-101 may have topped 250K units sold and lest we forget the ICOM IC7300 has surpassed 100K sold. The KWM-1 with 1250 units seems like a fly speck.
So what was your favorite radio or rig? Drop me an email and let me know.
As a follow on to yesterdays post, this is hamfest and flea market season. Don't pass up a good deal on one of those old boat anchors for with a bit of "N6QW Magic" you can have a really neat new rig for just pennies.
The colorful pictorial shows how to construct a VFO/PTO to replace the LO scheme in those old boat anchors. This bit of magic selects the proper range and frequency for injection into the boat anchor mixer stages (Buttons 1-5). But the slick stuff, in addition to the encoder knob, Buttons 8 and 0 let you up down tune the radio from the keypad and Buttons * and # let you transmit 10kHz up or 10 kHz down for those DX split operations. You can also select two large step tuning ranges for a fast QSY.
Detailed documentation is available at https://www.n6qw.com. While this was built for a Ten Tec Triton II -- it would easily work with the Hallicrafters SR-160, The SWAN 240, National NCX-3 and the KW Atlanta 2000.
I bought a rather pristine NCX-3 for $70 and it is a candidate for a makeover. You get full band coverage and think about FT-8 on 20M with a very stable NCX-3.
No new exciting rigs on the air that I created and my New Year's resolution regarding weight loss has gone south. Circumstances have just sort of happened. So how to recoup what is left in the 2nd half of 2024?
The physical building of a rig, in my view, is the lesser part of the process as that is something that can be and is taught to individuals who are not rig designers, but simply skilled craftsman. The hard part of the process is actually designing a rig for excellent performance. The key is research and information gathering. That is something that can be done without a soldering iron or Nano VNA being turned on.
The other aspect is the integration of new technology and new hardware into the designs. Older technology is just that. We can now operate radios thousands of miles away using an internet connection. It is a much more difficult task to remotely tune that LC VFO from afar.
While some may pooh and double pooh an SDR radio, the fact remains that the new technology is SDR. You need only listen to an SDR radio as compared to a conventional design using say TIA amplifiers and you will get the message -- loud and clear. There is a whole new world out there and the orb is not a Bitx40.
Of note I find that I am using my Hermes Lite 2.0 more and more as a test instrument than a station rig. It is indeed a real time spectrum display and in effect a frequency counter. This can all be done using a Raspberry Pi3B as the computer resource.
I spotted a less than $25 single board computer that to me looks like it could be a foundational piece in an SDR Radio. It is made by Orange Pi. (A quad core 64Bit, 1.5GHz machine.) It is from Lauren Sanchez's boyfriend (Bezos).
You will need a powered hub for more I/O and a power supply but that is peanuts. For field use, Mean Well makes a 12VDC to 5VDC, DC to DC convertor. Park this near a Wi Fi hotspot and FT-8 is at your command.
I have had great success with some small RF amplifier boards from the same source -- 2 for $9.
These are good for 30dB gain from 1 MHz to 2GHz -- for $4.50 a board. Another building block for an SDR radio.
You need only look at the SBitx from VU2ESE and it is apparent that he has moved to SDR.
It looks like the Chinese are firmly entrenched in the low end SDR radios and if not now will soon be leading the world for this market segment. Where are the US manufacturers? They are at the high end of the market and way beyond what I would spend. FLEX is out of stock for their $21oo SDR but you can get quick delivery on the $6K job.
Tour Amazon and it will blow your mind at what is available. Start your design process today.
Whether you roll your own or flash the plastic for a rig, the process has to start somewhere. Often the starting point is at the wrong end of the process. Let us define what I mean.
As hams we are often overtaken by the cosmetics. That radio is cool looking, or I want to build a cool looking radio. How many of you start out by saying I want a radio or rig that performs well? The ne plus ultra is to have both.
That plain black box with no knobs has no curb appeal -- yet perhaps it is one of the best ever performing radios. The flash is in the software!
The tangle of wires and PC boards mounted on a plank of pine can be and often is a DX machine.
The best place to start is with what often in government contracting is called a "requirements list". Let us use a real-world example: you are more than a closet POTA or SOTA guy --you are an addict! Every weekend is a planned adventure to some park or mountain top.
You scour data bases to see which parks or summits have not been activated -- one that has not been activated or only infrequently is moved to the top of your list.
It follows -- rare DX has the whole world listening for you and the same for POTA and SOTA. You make a schedule of events and if the XYL is not joining you -- you reassure her that you have only radio in focus for the time away. You are ready to go -- really, are you?
So, how did you decide what rig to use? Did your radio selection or homebrew rig consider what was required in the hardware. Things like how much does it weigh with batteries? Is everything in one box like a built-in antenna tuner or now you have to lug two boxes 2 miles straight up? How is the battery consumption?
One ham made a foray up a summit that had many radio repeater sites in close proximity. His SOTA event was cut short as his low budget Chinese box was desensitized from all of the RF floating around -- something he never thought about when he flashed his plastic.
Other concerns should be the mode. Will you do both CW and SSB or for efficiency or saving on battery consumption just CW. How about the antenna? Often simple wire antennas have a small footprint, and that smallness often results in a small number of contacts. Did you look at a pair of phased verticals to give your signal a bit of a boost. The fold down whip antennas is now looking a lot better.
Finally for a guy with FFS -- those small knobs will soon give you an acid stomach. The latest rig from Elecraft (KH1) would get a pass from me with the key and knobs mounted on the bottom -- it looks weird!
The homebrew rig presents many problems as the performance factors are not well documented as they might be with a radio that has to be type certified. Often homebrewers simply replicate already published projects and thus your mileage may vary. However, if your work is an original design then you have more control over performance.
Too much RF gain in the front end also amplifies the noise. Putting a modest amount of front-end gain with a lot of audio gain results in copying more of the weak signals. Forget those pixie style radios. Your requirements list should make clear -- 5 watts and forget 1oo milliwatts for a POTA or SOTA.
What is on your requirements list? BTW did you choke at the price point of the KH1 @$550 which is about where you can buy a XIEGU Model 6100.
Playing with the electrons most decidedly is like a British mystery novel or movie. Not unlike Murder on the Orient Express -- they all did it!
A couple of huge clues were totally missed by me in the resolution of a problem, and this also links back to the need to document everything. But 1st a bit of stage setting.
The Spilsbury Tindal SSB Transceiver
The above cool looking commercial SSB Transceiver was built by a company in Canada by the name of Spilsbury Tindal. It is all solid-state with 4 crystal channels operating in the 2 -10 MHz range.
Inside is a Collins 455kHz Mechanical Filter and a Motorola RF Transistor good for about 15 watts. This was a 1970's built radio. It was single conversion with a 455kHz IF, thus even making it to 10MHz involved a very large pair of cojones! [With such a low IF and single conversion as you go higher in frequencies images ARE a problem.]
The four crystal channels could be simplex (same frequency for Transmit and Receive) or entirely different. Internal to the set were a battery box and even a wire antenna. The primary market was the Canadian logging and mining industries. These often show up on eBay but command a pretty hefty price.
Of course, getting one would limit you to 80, 60 or 40M. But with a bit of Juliano Magic, the crystal approach could be changed over to the Arduino and Si-5351. Were you anchored down to keeping it stock then I would opt for four channels on 60M. Documentation and schematics exist on the Internet. So, the other option is to scratch build one. I did although not pure Spilsbury Tindal -- not even close!
This unit was built about two years ago but had some issues. The 1st notable point is the use of the ILI9341 2.2-inch display. This same code will work with the 4-inch display which would consume the whole front panel. If you are thinking Color TFT - get the ILI9341. A series of voltage dropping resistors takes care of the level shifting to the display.
Now to the mystery -- it just didn't sound proper on receive or transmit. The first test was to switch back and forth between LSB and USB. I added the two-sideband selection in the event I would make this into a 20/40M rig. A switch and a couple of added BPF and LPF filters and some relays would make that happen.
With any properly operating transceiver, switching sidebands should not make a huge (if any) difference in background noise. Such a state means you have the proper Carrier Oscillator frequencies, and these are placed on the filter slope at the right location. A non-symmetrical filter might result in frequencies that are not equally spaced from the filter center frequency i.e. not +/- 1500 Hz.
My replica uses a 9 MHz commercial filter and when you switched sidebands there was a huge difference. Initially, I had the LO at 23MHz and with a 9 MHz IF nets 14 MHz. LSB sounded stronger than USB and USB sounded pinched. I checked the code and the BFO frequencies were correct for that filter. So, my jump to the gun thought was a bad filter.
The next step was to install a new filter -- two wires and two nuts. Same problem. Then I tried a test where the LO was now at 5 MHz and thus what was USB was now LSB and the reverse. A most interesting outcome -- USB was now strong and LSB sounded pinched.
Then a small light in the tunnel led me to another possibility and one often is the last thought or never looked at all. I cruised up to 15.0 MHz to listen to WWV. I was receiving WWV at 14.998.8 MHz. The frequency was off by 1.2 kHz. The Carrier Boards for the Si-5351 have either a 25MHz or 27MHz reference crystal that must be calibrated to get the proper frequencies generated. You dial in 15MHz, and you receive (or transmit) on 15MHz when all is calibrated.
Failure to calibrate the Si5351 with a proper correction factor for the on-board crystal means all three clocks will be generating improper frequencies. The code may say one thing but what results will actually be different without a proper correction factor.
There are many references on the internet as to how to properly calibrate including a software routine. In thinking back some two years ago, I seem to remember I had smoked the Si5351 board which had been calibrated but the replacement was not.
My calibration process is to use my SDR radios where I sample CLK0 and adjust the correction factor in the sketch so what frequency that is being called up matches what I see on the SDR -- that can get me to about 1Hz. Sometimes on purpose I leave it at 20Hz off -- just so the FLEX guys can tell me I am 20Hz low. A few trial runs will get you the right calibration.
So, a calibration of the replaced Si5351 resulted in that switching sidebands has no change in background noise and when you tune 15MHz WWV --the rig reads 15MHz. Mystery solved with a culprit not 1st on the list to check.
TYGNYB!
73's
Pete N6QW
PS. When I searched the Internet for a calibration routine, I found a website that had the process. When I went to copy the link --it was on one of my own websites. Scary is a good word.
Having a wheel of fortune like device in my garage I use that to select topics for the blog. Today it landed on 17Meters.
This band undoubtedly is a Hidden Gem! Typically, devoid of any contest crap like Field Day it can provide many contacts including DX QSO's, all at QRP power levels. I worked my 1st ever station on Saipan using FT-8 at 5 watts on 17M.
The bonus is it usually is devoid of those hams in call areas 5, 7 and 4 who start cocktail hour at 6:00AM -- you know the ones that lurk on 75 M.
Some 17 years ago I built my 1st ever 17M SSB Transceiver. That was my 1st attempt at building a Shirt Pocket SSB transceiver which didn't quite get there but it was small. The IF was at 4.9152MHz and used a crystal switched VXO that covered most of the phone band. The final was an MRF260 which was good for about 3 watts output.
Fast forward to 2023 and I decided that technology would move that radio from VXO to the Digital world and taking the 7X7X2 aluminum chassis enclosure it was modified to incorporate a rather spiffy looking Color TFT display.
N6QW 17M Homebrew SSB Transceiver
17M SSB VXO Version
Of note it has two VFO's with memory and the 2nd VFO boots up on the FT-8 frequency. This affords a quick way of checking band activity. If there are FT-8 signals present, then the band is open.
Couple this jewel with my Digital Adapter along with a Raspberry Pi Zero W and you are cooking on FT-8. An advantage of 17M aside from sidestepping the inebriated hams is that the antennas can be quite small so great for those small postage-stamp sized lots.
Now a twizzle on this project would be to add a second set of Band Pass and Low Pass Filters so that when you switched bands instead of 18.1MHz the rig would boot up on 40M. The SPST band switch below the display would be changed out with a DPDT switch and add the filters and you are there! One or two lines of code changes would round out the conversion.
TYGNYB. The 40M would open things up for the POTA/SOTA guys.
73's
Pete N6QW
PS: Someone will ask so best answer this up front. I used the existing on-board Crystal BFO so the change in 2023 did not include the LSB/USB select. If the two-band version is in the "idea chamber" then it would be best to actually "ON" the BFO in the Si5351. Just the value of the BFO is used in the code for a proper display and the BFO is not actually turned ON in the code. If you choose simply to run the LO at 2 MHz and sideband inversion would automatically give you LSB. NOT a great idea because of BFO harmonics slipping through the 7MHz BPF. This was covered in the link. Thus, placing the LO above 40M would be the better option and using the LSB Carrier Oscillator frequency. You would also need a USB/LSB select switch to the mix.
If you are in the less than 1% of the ham population who actually rolls their own (homebrews) their rigs, then this is the publication you want to arrive in the mail.Roll your own refers to an era where real men rolled their own cigarettes and never resorted to store bought ones. Same idea with rigs!
In yesterday's mail in addition to all the junk mail received from both political parties asking for my money, my Summer SPRAT arrived. The SPRAT is a quarterly publication of the G-QRP Club.
Talk about giant sized panty hose, this issue has something for everyone. We have rig construction for both solid state and valves (tubes), some articles on test gear and antennas and as a bonus how to build a HT (high voltage) power supply for use with tube rigs.
The articles are short and for the theory nuts, you will not find a discussion of third order linear regression. But for those who are extra class license holders this is a gap filler of what you should know to hold that license.
One really cool short article is an analog meter tester -- just a handful of parts is all it needs. So, when you spot that neat 100 microamp 2.5-inch round meter for 50 cents at a flea market -- this jewel will tell you if it works. This specific meter is perfect for a homebrew SWR Bridge which you can find described in SSDRA.
There is an update to the W7ZOI Micromountainer rig that shows how to use a substitute PUT. I will let you find out what a PUT device is -- you can Google it.
How about a three band two valve receiver or perhaps a Direct Conversion Receiver construction article. Predominant on the front cover is a Ten Tec Argonaut, the 509 version, where the author had a several decade quest to find one and make it operational.
One particular section covers member news where there are many photos of projects that have been built which includes the call sign and short description of the project. This is an eye opener to see what is happening in our hobby.
The bonus is the back cover that has a listing of hard-to-find parts that are being sold by the G-QRP club. Part alert -- they have crystals for the CW primary calling frequencies (ie 14.060MHz). The most difficult part of the purchase process is the money conversion as the crystals cost 50p. But good old PayPal takes care of that problem. The dispatch of parts is quite excellent. (dispatch = shipping).
Yes, several of my projects have been published in SPRAT and often I receive emails asking for info on a project, so I know it is being read world over.
Despite my best laid plans, I did not operate during Field Day this year! My garage shack was 94F at 1300 PDST and that was just too hot, so once again foiled by Climate Change.
Well not all bad and I think that band conditions were not so great despite the Hoopla about Cycle 25. (This is to offset my disappointment at not being able to fire up the KWM-1 on 20M for FD.)
But I did think this would have been the time to have a 2nd wireless router as I could have operated the Hermes Lite 2.0 remotely from inside my home (with AC) using a laptop. Probably need to do that. If I had a 50-foot chunk of CAT 6 cable that would have worked too. The wireless router needs to be further investigated -- summer is just starting.
Now this is where it gets interesting. Wireless routers go from around $50 to $1000. It is all about a 29A versus a 44DD.
Recently in attempt to lower my cable bill, I made some changes to my Frontier Communications hardware. This change knocked $100 off of my bill. This now included an eero wireless router so that seems to be what they use. Every so often my laptop which is 15 feet away can't find the router so that also is a datapoint.
Lauren Sanchez's boyfriend sells a refurbished eero for $55. BUT don't get that one! It is too slow for the HL2. You need 1Gbps for the HL2 and this low cost one is only good for 550Mbps. This now moves you up to $90 for this eero.
A message here -- don't be fooled by the low price -- make sure what you are buying is indeed what is required. It's an eero costs only $55 but too slow!
Any readers have suggestions for a high speed 1Gbps router for my HL2?
According to an unreliable source (The Internet) Marconi is fingered as the 1st ham. But in fact, it was Heinrich Hertz who is credited with the theory that there could be radio waves back in 1890. It also said the 1st ham club was not at MIT or Stanford but Columbia University in 1908.
But with certainty the period 1930's to 1960 produced some really cool looking radios (with some exceptions like the S-38E or the SW-54). The designs had curb appeal and for some strange reason could capture your heart just like a blonde hottie.
One radio manufacturer product line I never owned was one from Harvey Wells. The R-9A and T-9o (receiver and transmitter) were two examples.
The R9A Receiver! The knob in the middle was a band switch and main tuning.
The T-90 Transmitter. Same deal on band switching and tuning.
These two radios were small in size as one of the market segments was as a mobile rig. The transmitter had a VFO and could also be crystal controlled. The power supply for the transmitter was external and there was even a mating Z Match Antenna Tuner. I have no data on just how popular these radios were, but they sure caught my eye. Big negative my FFS and the small tuning knob.
One other product line from Harvey Wells were the Bandmaster transmitters which command a fairly high price on eBay today. They had variants such as the Senior Model and Junior Model. The variable was power rating and features. These looked like something you might home brew in your shop. Most were Phone and CW capable, but crystal controlled.
Harvey Wells Bandmaster Senior
The R-9A and T-90 show up from time to time on eBay and all you need to do is search BAMA for the manuals and you will quickly conclude to pass on the units.
Still another lusted after radio was the Hammarlund HQ-180A as that just had such a cool look.
I never owned an HQ-180A but thought this was somewhere between the SP-600 JX17 and the HQ-100. I did own a SP-600 JX17, and it worked well but weighed a ton. I bought and sold quickly a HQ-100 -- just slightly better than an S-38E. Pair the HQ-180A with a Johnson Viking Valiant II and you had a serious (hernia) radio station.
Perhaps the forerunner of the Transceiver was a jewel from Hallicrafters. This was a desk station console that included an SX-101 Receiver, HT-32B Transmitter and HT-33 Linear Amp. That thing must have weighed several hundred pounds and cost several thousand dollars. I don't have a photo of that station, but you can just imagine telling the XYL look what I bought with the charge card (forerunner of a credit card -- this was the 1950's.)
I spent a bit of time today with some radios of old as these might be what you found on the operating desks of the hams 80 years ago. Today it is either an ICOM IC7300 or a black box with no knobs.
Like a broken record I keep saying my time is very limited. This in turn leaves little time for new builds, but instead I have been hitting the "shelf of shame" and actually fixing some radios that are broken or never did work right.
This presents some special problems as there often is a significant time lapse when I last worked with the rig. Thus, what I did previously often is a mystery that has to be unraveled.
A second larger and perhaps more dangerous malady is the case where I did not follow a standard layout. Hookup often follows muscle memory which by wrote is for the standard.
Using an IF Module has worked very well for me. In a recent post I think I shared there were 7 different topologies for this module. Here is one using the Plessey approach (2N3904 & 2N3906) only fully SMD.
Deft Hands and Headband Magnifier is the order of the day. The Cores are FT-23-43
Typically, in my IF Modules I have the Band Pass Filter on the right-hand edge and right near that is the Rx Tx Mixer, an ADE-1. On the left side is the Product Detector and Balanced Modulator an ADE-1 also.
The P3ST with the Left Side ADE-1 PD/BM and Right Side ADE-1 Rx/TX Mixer
Shame Shelf: Left Side ADE-1 Rx/TX Mixer Right Side ADE-1 PD BM
In the case of the P3ST the left most ADE-1 would have the Carrier Oscillator (CLK2) signal applied and the right most ADE-1 would have the Local Oscillator (CLK0) signal applied. This is more or less the standard committed to muscle memory.
So, along comes the Shelf of Shame rig which was built several years ago and has a reversedlayout. But this rig had the Si5351 and Arduino liberated from the circuit along with some other modules. Not a problem as I have many built up modules just awaiting a project. I did a quick bench test of the spare Digital VFO, and the screen lit up and the controls did their thing.
Upon hooking things up. The rig was as dead as a door nail. Luckily, I had to stop as I needed to head out for my shift at the Board and Care. This was indeed luck as it gave my mind a chance to mull over what could be the problem. I didn't come up with much during that three-hour period.
It wasn't until I was just pulling into my driveway that it hit me. Hey, dummy you wired the Carrier Oscillator and LO as in the P3ST (standard) but this one was reversed. So, the LO was connected to where the Carrier Oscillator should be connected and the same for the other ADE-1. A bit of cable reversing, and it came to life.
Then I noted the received signals sounded distorted and that switching between LSB and USB there was a marked difference in the background noise. Typically, they should be about equal -- but now the difference was huge. I looked at the sketch and using a commercial filter the BFO (Carrier Oscillator) frequencies are pretty much stock, so I tried adjusting the BFO frequencies in the sketch. There was some improvement but not enough to cure the issue.
I am now suspecting a bad crystal filter. So that is the next area of investigation. It was on the Shelf of Shame for some reason and that may have been the issue.
The huge takeaway is to keep better documentation and to make some notes on paper and stuff that in the rig before installing on the shelf of shame. I wasted precious time yesterday trouble shooting a problem I created.
Thus, the thrust of this posting trust no one least of all yourself! You think you are merely passing gas but in reality, you should have had the Depends on. It might be OK to have trust in your gut but never your butt!
So, today around 1300 PDST look for N6QW, 1DCA, somewhere between 14.2 to 14.3 MHz yelling CQ FD using my 66-year-old KWM-1. That'll show those IC7300 ops what ham radio is really about. BTW everyone is always 5X9!
Summer brings all sorts of wonderful opportunities. Some involve ham radio and some focus on the food consumed in the summer months. Things like watermelon and corn on the cobb or the tons of burnt burgers cooked on a charcoal grill.
This definitely would not get Mary Jo into the back seat of the 57VW Bug!
I mention foodie stuff because non-contest ham radio this weekend will be a bust with Field Day. So, if you just want some friendly QSO's forget it until next Monday.
This might be a good time, if not participating in Field Day to think about station accessories. I am often surprised that many stations do not have an in line SWR bridge. If you were smart enough to ditch EMRFD and acquire SSDRA, you can find some nice designs for homebrewing a SWR bridge.
For those who do not fear the Arduino you can do some code modification to include a Tune Up functionality built into the code. Typically, all of the code I develop has a Tune capability.
So why would you need a Tune function in your homebrew rig? One of the primary reasons is to provide a bit of RF to the antenna to assure you have the lowest SWR. Another is to determine if the rig is operating properly. Still another reason is that you are one of the cool guys who has this capability.
[For those forever welded to the Bitx design, I have always been surprised that a Tune Tone was not in the original design. In a Bitx40 I modified so that it does both LSB and USB (for FT-8), it also has the Tune Function.]
The theory of operation is simple. The Arduino is capable of generating tones using the Tone library. One of those tones is 988 Hz. So, firstly we generate a tone at that frequency, and next we set the code so that it is on for a certain time period and the off for a certain time period.
We ask the code to do this for so many cycles using a loop counter. We now have essentially created a pulse train of so many cycles, typically about 10 seconds. This pulse train is then introduced into the microphone circuit. Unless you add some isolation, you unplug the microphone and use the MOX switch as you don't want to back feed audio tones into the microphone.
Now a bit of a sewer backup. The Arduino output is like a square wave, so we need to set its level (trim pot for just a few watts) and add an RC Filter to turn those square waves into a sinewave. I think there might be some issues with harmonics of the generated sound wave if they are left as pure square waves.
Essentially an engagement of a momentary push button starts the tune sequence. Now in several of my rigs this also trips the PTT switch while in others I simply engage a MOX (manual switching of PTT in addition to the PTT on the microphone) and then hit the Tune button. The MOX approach also offers a way to have the transmitter on without having to use the Mic like for troubleshooting.
Once the 10 second sequence is over the rig goes back to receive. Now to be totally Kosher you need to station identify your station once the test is complete. OR as I did in a couple of rigs simply extended the code after the 10 seconds to send my call in CW. This also opens up the possibility of an automated station identifier as in a CW beacon.
OK wasted enough of your time so I will end this. If you want the code snippet for a Tune Tone, email me at my QRZ.com email address.
CQ FD, CQ FD. The station calling me, you are 5X9. Please repeat your call several times so I can log you.
Yes, that was a part of an exchange in a recent Field Day. That IS a case of Brown Shoes with a Black Tuxedo!
Field Day is upon us -- are you ready? Did you buy the several cases of Rolling Rock Beer, the three boxes of antiacid, Beano for the Spicy Chili and Bratwurst, a gallon of mosquito repellant, a new cell phone charger, SPF 100 sun block and loose pants. Don't forget the air wick and toilet paper for the Porta Potty. Long ago, JIC (just in case) if Mary Jo showed up mustn't forget some Bob's Big Boy Hamburgers.
This is a wonderful photo of a 112-inch military style (I didn't say military grade) folding whip antenna. This has the makings of a neat antenna system whether for FD or POTA/SOTA operations.
I have one and Lauren Sanchez's boyfriend (Bezos) carries these at a cost of $45. They are well made and with some base loading coils and a matching network could work nicely with the Xiegu G106C Transceiver and the BJ-200 50-watt amp on 20M and up. Get out the plastic -- you only have 2 more days.
Baase Loading Coil. Use an Alligator Clip for the matching; Use a 3-wire counterpoise.
Use a car for an Anchoring Mechanism.
If I were to do FD, I would use an SDR QRP radio fitted with FT-8. But with a Twizzle -- I would locate outside a place that had free Wi-Fi. Then using my folding whip mounted on a camera tripod with a counterpoise, I could sit in an outdoor seating area and just enjoy the scenery -- after all ham radio IS a Chick Magnet.
This FD should prove interesting as I have noted the last two nights at around 8PM Left Coast time that the path to Russia has been wide open Several RA3 and RA5 stations were heard at a real 5X9 and no response back. Was this a boycotting of any Russian stations or a case most hams think the band is dead. Of note I frequently hear no SSB stations on 15M, but the FT-8 and CW stations are really loud. So, maybe this is a clue of where and what time to operate.
So, you have this project, it uses an Arduino or Raspberry Pi or maybe even a plain old LC VFO and now you need to have some sort of readout.
3 Inch Color TFT
You are now faced with a menu from a Chinese Restaurant. One choice from Column A and perhaps two from Column B, capped off with a single choice from Column C. Yes, that is the dilemma.
The LC VFO in the old days could be mated with a combo Vernier Drive and semi-circular dial scale where you hand printed the frequency info on the scales. National and James Millen made such units.
James Millen Drive and Dial Mechanism
Today's version is a 3X5 File Card marked with a fat black sharpie pen. Crude is a great word! Or if uptown you could use one of those packaged LED counters that can be offset by the IF. (San Jian about $15 for a six-digit unit.) Besides whom in the proper frame of mind would use an LC VFO when the Digital VFO is so much better.
Moving to the Digital Side we have the Chinese Menu. At the shared top tier, we have the 16X2 all the way to the 20X4 LCD's. Needing only 4 connections if you use the Backpack adapter, a lot of information can be displayed and in fact using some menu tricks the 16X2 can be turned into various screens and thus not just a single 16X2. In passing I have also used an 8X2 which is really a challenge which is shown here with an early Bitx40 that did not come with the Raduino.
8X2 LCD. It drew so much current it needed a separate power supply for the LCD
If you use the Xiao RP2040 MCU, you are somewhat limited to a lesser number if IO pins, and thus the 4 wire LCD is likely the 1st first (and maybe only) choice.
The LCD's come in backlit and non-backlit (bad choice) as well as various coloration such black lettering on a seasick green background or my favorite, Juliano Blue background with white lettering. [The non-backlit are really cheap but hard to read in direct sunlight.]
A word about ease of implementation and cost. The 16X2 is like the old camera ad (point and shoot) -- point to one of 16 locations and tell the code "Print here". A bit tricky is that the spaces are numbered 0 - 7 and 8-15 and Line 0 and Line 1. The LCD's can be found much cheaper than the Color TFT's. The backlit versions can be really power hungry so having the display lit all the time in a portable setting can drain your battery in short order.
Of note the LCDs operate on the I2C buss and therefore share the same 4 pins as the Si5351. Information in the code must designate the I2C buss location of the LCD such as 0x27 (pretty much the standard). And of course, Adafruit in some of their offerings use a custom code. If your LCD doesn't display and is wired correctly, there is a good chance it is your I2C address in the code.
The other side of the Digital Menu are the OLED's and the Color TFT. This is where the menu becomes a fold out road map. The OLED's have limited color choices but can be really small. The equivalent to the 16X2 is 1/2 inch high by less than 1-inch-long OLED. This takes up very little panel space and the current drain is better.
Now on the menu is the Color TFT (Thin Film Transistor) LCD technology. Short answer better image quality and faster addressability. Another huge plus --screen sizes up to 5 inches that don't require a home loan. I have Color TFT displays less than 1 inch square to 3.5 inches. For us older folks -- the 3.5-inch job sure makes things easy to read.
But the Color TFT's need about 7 to 8 wired connections and more panel space because of their size. The big bonus is colors and viewing area -- the big negative -- you have to have some programming skills and patience.
One huge problem is what I call overwriting. Let's use an example. I often display the mode such as USB or LSB. A couple of ways to do this is to have one location where you simply change the letter U to an L and the SB is always fixed. So, you hit the switch for LSB and the U changes to an L. Going the other way on USB the L changes back to U. Unless you make some provisions in the code you will see U and L simultaneously.
So, in the code if you are switching from USB to LSB, the code will first say the print color in the "U" space with the background color (usually black) and then the code says print the letter L in the normal print color. Thus, the overwrite is in black and the next overwrite is the proper color. In transitioning back, same set of code for the L and U.
I frequently just use two separate blocks of space where I write USB or LSB but use the same overwrite by calling out the print color as black or the proper color.
The programming is a time-consuming effort for the Color TFT and likely for many the 16X2 is the answer.
The sensibility of displays all comes down to the effort needed or required. For just basic info it is hard to beat the 16X2 which also likely costs the least and involves rudimentary programming. While I did not previously mention it, many of the Color TFTs are touch screens and this give the user a more hands on control of functions. This is kind of a curse for those of us with FFS.
A shift from vacuum tubes to solid state also created a seismic change in how we built things. Some of us witnessed that change firsthand especially in things like a chassis and cases. Want sticker shock go look at Jeff Bezos website and search on aluminum chassis?
Certainly, some of that cost is in the metal as often the aluminum is from offshore. But another is the old supply and demand. Of course, one answer today for one aspect is the 3D printing of plastic cases but another may be this jewel.
An 18-Inch-Wide Metal Break~ Harbor Freight
My shop has one of these and today's price is about $45 but long ago this was only $27 when I bought it. Now you will need some things like large C Clamps and some short pieces of metal to bend small parts, but you can build a chassis or case using this very tool -- I did. Also, Home Depot sells galvanized metal flashing really cheap which is the source metal.
350VDC Power Supply
Now not everyone who home-brews will need a HV power supply but certainly this would work for a 12VDC supply. What may not be obvious but the whole chassis is only 3 pieces, two of which are bent up.
Two sides and a top piece.
A couple of notes here include laying out the metal and locating the holes for the final assembly. All holes are drilled while the metal is flat and not bent.
The small metal pieces mentioned earlier are used as an auxiliary bending bar to make that small right-angle bend. The sequencing of the bending is also important, so you don't bend over stuff already bent.
The galvanized metal seems flimsy but when bent over and assembled is surprisingly solid. This has something to do with metal pieces in tension and compression. That power transformer weighs several pounds, and the metal does not buckle. The top plate is of course thicker and more rigid than the sides. It is solid from the get-go and contributes to transferring any loading to the sides.
A small chassis
The Transmitter portion of a Paraset.
The 350VDC supply was used with this Paraset transmitter. This chassis was a bit flimsy because the bottom is open and should have had a bent over lip. Yes, I was short on material and a bent over lip would also support a bottom cover. Next time...
So, a small investment from Harbor Freight yields a tool that can be used for making cases or a chassis.
Let me not fool you that just because you found another place to spend the plastic, it does take some knack to be able to pull off making a chassis or a case. You have to be able to visualize the final product and mentally sort out the bending sequence.
That is a skill not everyone has so now open up a browser, search Amazon and buy it now. But if you made it yourself you would have bragging rights -- even the chassis and case are homebrew! WYKSYCDS!
It is a siren's call! It is burning a hole in your pocket and almost as good as Mary Jo after a feast on a Bob's Big Boy Hamburger.
So yesterday was Father's Day and I announced that if any presents should pass on to me that the wording Amazon Gift Card should appear somewhere. That worked well! Maybe blog readers were clever enough to use my ploy and you too have some gift cards.
So now I am flush with resources and a visit to Amazon produced this jewel.
This 50 Watt CB "leenear" good from 3 to 30 MHz can be had for $70. It has two (not one but two) 5 Star ratings.
This is certainly tantalizing especially with the ARRL Field Day coming next weekend. Or you POTA, SOTA, IOTA guys can get the Xiegu GC106 and with BJ-200 operate at 50 Watts from that exotic location.
But just like a blonde hottie likely the looks belie what may be under the hood. There are some telling things just from the outset -- so before you flash your Amazon Gift Cards -- what are you buying? The write up is certainly scant. There is a caution about not using high and low voltage -- the Vin is 13.8 VDC so I see a flashing red light and have no idea what that means! The Model Number is BJ-200 which is maybe a clue -- Bad Joke #200.
Firstly, the packaging and size (and cost) make you drool. But there is no band switch so likely one (or none) Low Pass Filter in the mix. But that is OK as you can always add external LPF boxes.
Next, a real RF Device will cost more than $70 to produce 50 watts. Thus, some IRF510 type devices (maybe IRF530) are in the mix where likely you could see 50 watts on 20M but if lucky only 25 on 10M. But that may be OK as on Field Day everyone is 5X9.
Has the "RF in a Box" passed by the FCC and is it type certified. Like the Baofeng UV35R -- many are sold and if you get a pink slip from Friendly Cousin Charlie (FCC) it is on you for using the device without 1st checking its legality.
But you argue -- it was sold by Amazon!
On the other side the new technology and improved manufacturing processes plus Chinese dumping of products could in fact bring viable products that sort of work for a price of $70.
I would not rush to buy this although terribly tempted by this red headed hottie until it was clear what is in the box and how good of an amp it is. But if it does pass the smell test this would be a great afterburner for a QRP radio.
So, OK the temptation is too great for you -- after you get it working let me know how good it is.
I call this a "regret rig" as this jewel had some really nice features. It was a Trans-receiver and used a Varactor Tuned Oscillator which was shared between the Receiver and Transmitter.
The receiver is a Superheterodyne with a 4 pole filter and of course the now unobtanium 42IF123 10.7 MHz IF transformers (BPF) padded down to 40M. It had a IRF510 in the output stage and a sprinkle of NE602's for the Product Detector and Transmit Mixer. Single Sided Copper Vector Board was used as the main circuit board.
Now the regret part. I gave this to a new ham who had no station equipment. In short order he smoked it and then salvaged the parts.
This design was not documented and few photos were taken. It was a small footprint and operated much like Mary Jo after a Bob's Big Boy Hamburger.
I believe in trying to help out fellow hams, but my eagerness must be tempered with what I call an appreciation factor.
The new ham just didn't appreciate what he had and I didn't even think that someone who was given such a rig would not have my appreciation of what it took to design, build, test and get it working.
Both of us would have been better served if I had just given him the parts, with a documented design and offer of help. This would have been a better learning experience for him and no regrets that my effort was smoked and permanently damaged. Well at least this ham didn't trade the rig for an RC car like one ham did with the homebrew Bitx20 I gave him.
It is biblical in a sense -- give a man a fish or teach him how to fish. I keep seeing how I have failed to realize that as an OT it is better to not give away radios/rigs but to encourage those who have no rigs to build one. Building this radio could have been such a great learning experience for the new ham. Likely now he has an ICOM IC7300 which he would never open up.
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