SolderSmoke Podcast #252 -- First Podcast from SolderSmoke Shack South

For the moment this podcast is video only.  The video appears above.  Here is the URL for the video: 

https://www.youtube.com/watch?v=NeNTv3YjiHU  We will try to get the usual audio podcast version out soon. 

-- This is the first podcast from SolderSmoke Shack South:   Eastern tip of Island of Hispaniola.  Cap Cana, DR, 70 feet up, 1 mile from Mona Channel.  Seventh floor shack with view of the ocean.  Antennas:  Dipoles for now, maybe Moxons or Hex later. STARLINK

- The San Francisco case against me.  One guy thinks we DESERVE prosecution!  Get off of my lawn! 

Like the library cop on Seinfeld: https://www.youtube.com/watch?v=D9tP9fI2zbE

But one fellow wrote letter to the mayor asking for leniency.  Proposes "Bill Meara Day in SF." FB!  I fell victim myself this year:  Mike WU2D got me with WA1HLR on SSB video. https://www.youtube.com/watch?v=NLvCNJ_OnEc

-- Dean:  Fighting a spur in the sBITX.  Filters? 

-- Dean:  Exploring Class A, Class AB and the RD06HHF1

-- Dean: Extensive work on getting flat gain from FETs up through 10 meters. 

-hh- Dean and Bill:  OIP3 measurement and setting the bias on an RD06HHF1

-- Pete:  Discovers for all of us "RF Man"   In spite of all the CB stuff, he is the THE MAN!  On YouTube:https://www.youtube.com/@rfmanchannel6915

-- Pete fixes Dean's relay chattering problem: SUBTHRESHOLD CONDUCTION!  Yikes!  

-- Pete's refurb and rejuvenation of the Drake Twins, 

-- MXM news.  New docs, and ads from WD5L. All on the blog. 7030 crystals.  Why MXM? Chuck Adam's mods, Joh DL6ID's questions about VFO.  Yes!  VFO from RX.  Was Bruce Williams an early Swan Designer? 

-- Weird paradox with 25 MHz filter:  Low profile xtals have higher Q, but produce more rounded passbands.  Why?  I note that Minima's 20 MHz filter also had curved passband. 

-- Allison's wisdom on filters at higher frequencies.  The importance of physical layout.  Diodes in the dark!  It is indeed more difficult up there.  But don't let the perfct be the enemy of the good!

-- Is Bill  the only one to ever build a 10-15 Dual Bander using a 25 MHz crystal filter.  Why?  Farhan's Minima has a 20 MHz 6 pole QER crystal filter.  And it too had a rounded passband.  But it tooc WORKED.  

-- Did my receiver sound tinny due to rising frequency response of uBITX Rev 4 amp?  Yes! So I put in a  TJ DC RX Af amp.

-- Bill BLOWS UP a Tiny SA Ultra. Ooops.  But quickly got a new one from R&L Electronics.  Very, very useful.  I knew 25 MHz IF rigs were inferior, but by how much?  How much was the carrier suppressed?  Which filters worked better?  What was the opposite sideband rejection.  TinySA permitted measurement and comparison. 

-- Bill quit 15 meter SSB (for a moment) and went to the 1.22 nanometer band with a Wilson Clound Chamber.  Videos on the blog. 

SHAMELESS COMMERCE:  Thanks to new Patreon sponsors.  I am sending some additional video content to the sponsors.

MAILBAGg

-- Thanks to Bob Crane W8SX for FDIM interviews.  I will get them out! 

--Wes -- W7ZOI has a new TIA amp with variable gain on his web site: https://w7zoi.net/

-- Geoff N6GWB's Rad Receiver https://soldersmoke.blogspot.com/2024/04/the-rad-receiver-from-n6gwb.html

-- Dave K1KA sent Ensemble RTX SDR parts.   Thanks Dave. 

-- Chuck Adams AA7FO provided good background on my MXM rig, including the meaning of MXM (1990) . Again, great to hear from Chuck, a true homebrew hero.

-- Gerardo HI8P collecting info on the other HI8P, my friend Pericles (SK) 

-- Alvin N5VZH picked up a Silktronix CB VFO.  What to do? 

-- Jorgen SM4WWG listening from Sweden, and making PCBs.  FB! 

-- Mike WN2A  Wondered about opposite sideband rejection of MXM.  Not great. 

-- George WB5OYP loaned me a book from Elmer Bucher.  THE Elmer?   https://k9zw.wordpress.com/2020/01/24/on-the-origins-of-elmer-a-reasonable-theory/

-- Wes W7ZOI, Farhan VU2ESE -- Thanks for help on filter issue. Thanks too to Alan W2AEW and G3UUR

-- Josh G3MOT -- Nice message of support in our "struggle" with SF authorities. Going portable to Vancouver island in August.  VE7/G3MOT

-- Paul VK3HN -- Antipodean solidarity.  Thanks Paul. 

-- Rogier PA1ZZ -- great input and help. Thanks

-- Tony G4WIF reminded me of G3ROO's  parasets.  See Blog

-- Pavel CO7WT His experiences (building, freezing, heating) the VFO in the Jaguey DSB rig.

-- Grayson KJ7UM Sent latest ER with his Collins 51S-1 story. Thanks Grayson. 

-- Allison KB1GMX  Commiserating on higher freq crystal filters. Thanks Allison 

-- Wes W4JYK Notes that Dewey, Cheatam and Howe are based in SF. Can they help with sticky sticker problem? 

Re-building the Islander DSB/CW Tube Rig in Cuba

The VFO Board

The "motherboard" for an Islander

Islander boards recently obtained in Cuba by CO7WT

Pavel CO7WT is making great progress in re-building an Islander DSB rig, the same kind of rig that got him started in ham radio, and that was so popular in Cuba years ago.  Here are some background blog posts on this rig:  https://soldersmoke.blogspot.com/search?q=Islander  In essence, the Islander was the earlier tube DSB/CW rig; the Jaguey was a later, solid-state DSB/CW rig. 

When they get this Islander going, hams outside Cuba should definitely try to work this re-creation of an important rig. 

Thanks Pavel for all the information.  I will share with the group info that Pavel sent about temperature stabilization techniques used on this rig.  

Pavel CO7WT writes: 

Great news, today I received the package from my colleague in zone 6.

Two original islander motherboards and one from the vfo!

I'm doing a search among old technical friends in the city and in the country to see if I can put together at least a transceiver motherboard.

Audio triode-pentode is easy, as is tx pentode and audio double triode.

The difficult ones would be the 6cb6 and 6bz6 of the receiver... At least according to what I have polled among my local friends...

Tomorrow some friends are going to start looking for bases and valves that can be used to build a trx islander.

All out of pure nostalgia. I intend to make it qrp, that is, up to the output pentode, which there is between 3-5W of power, that is enough for me.

I am looking for alternatives for small sources, perhaps I will use switching for the filaments and we will see what I can get for the 180-250v of the plates.

Earlier: 

CO7WT here, built a pair of the Islander back in the time, the most scary part was the power supply.

The 600V is 300ish V from the transformed DOUBLED stright from the transformer and if you look closely on the diagram the doubling capacitor need to be of good quality otherwise it will explode in the spot.

As you can imagine, using scrapped parts means that very often this capacitor explodes, even after a few months of duty, that was a common problem.

We used to use 47uF/800v from Germany that was almost easy to obtain, but exploded like fireworks a given day.

Later I learned that if you put a resistor of about 1k 5W in series and work it for a while like this [no real voltage at the end] it will behave in the future and this trick saved many, a trick that was shared with Coro CO2KK and he found the explanation on the taming/training of the dielectric after storage/inactivity will prevent it from exploding.

I think he made mention this on a DXers Unlimited program...

A Cuban Knack Story, and a Pandemic (SITS!) SSB version of the DSB Jaguey Rig -- Viva el Cacharreo!

 

First, the Knack Story.  Andy CO2AFV clearly has The Dilbert Disease: 

Hello my name is Andy. I had an interest in Ham radio before knowing that existed.  While I was a child my entertainment was building quartz oscillators that later I tried to receive on neighbors' and friends' radios. One day I succeeded in modulating two of them and I finally established a conversation with a friend about 200 meters from my home!!!

Andy with his FB HB rig

Here's a description of a version of the 7 MHz Jaguey transceiver that Andy built during the pandemic.  It looks to me as if he took the Jaguey DSB rig and added a 455 kHz filter with an additional mixer to turn it into an SSB rig.  So he is generating the SSB at 455 kHz, and mixing it with a VFO running at around 6.8 MHz.  The sum output would put you in the 40 meter band; the difference output at around 6.35 MHz could (mostly) be knocked down by a bandpass filter.  I think the Cuban Radio Federation Web Site gets it a bit wrong -- the purpose of the filter is probably to eliminate the unneeded sideband, not really to suppress parasitics. 

Federation of Radio Amateurs of Cuba Published: September 17, 2020 Viewed: 2352 Comments: 12 

Radio Transceiver CO9BIA 455 A construction carried out in times of Pandemic by its author, Andy Fernández Valdespino (CO2AFV). 

Cuban radio amateurs continue to accept the challenge of isolation caused by the incidence of COVID-19, but this does not mean they paralyze their activities. Such is the case of Andy Fernández Valdespino (CO2AFV), who for more than four months has been working on the development and construction of a new transceiver, the CO9BIA 455, a device that already works perfectly in the 7 MHZ Band. 

Andy, who is technical secretary of one of the Havana Radio Clubs, has to his credit the construction of two Jagüey-type radio models, as well as several types of interfaces for programming and Digital Modes; and various prototypes of antennas, among other elements that make up its constant “cacharreo” activities, as we say in our language. 

He has now completed and tested a new model that he has named with the callsign of his Radio Club, CO9BIA, and the model 455 is due to the use in this prototype of a filter of the same capacity. Asked about the details and other construction bases of this radio, whose transmission and reception tests using only outputs from the driver were carried out on September 14, Fernández Valdespino pointed out that his objective was to build a portable QRP equipment, of very large proportions. small, that it would be capable of being operated in the 40 meter band on both sides, by incorporating an improved VFO from the traditional Jagüey, but this with some modifications, and that the radio in question would work powered by a 7-inch battery. .2 volt, the same ones that come with most of the “Handy” used by radio amateurs. 

To complete the “portability” characteristics of the new radio, the possibility of exchanging antennas has been incorporated, and a very light variant of the telescopic type can also be used, just over one and a half meters long. Andy explained that for the development of the new equipment, he was based on studies that he has been doing on some of the characteristics of the Jagüey, a direct conversion radio with very good sensitivity, but that does not have good selectivity, so in the conditions of the current solar cycle, its behavior is not optimal. In Jagüey, the signals, after being modulated, do not pass through any band-pass filter, which causes many “spurious” signals to be released into the ether, which represents an obstacle to be solved in order to incorporate a linear that can increase its output power. All of this, the creator assures, was taken into account for the construction of this new design. For example, in the transmission step, in the CO9BIA 455, the microphone signal is mixed, pre-amplified, filtered and re-amplified, until it is delivered to the 455 kHz filter, to finally be mixed with the VFO signal; and as a result of these steps, the sum and subtraction of these mixtures is obtained, which are in the order of 6 and 7 MHz. As a final result, after these signals are injected into the input bandpass filter, only one output is obtained of 7 MHz, whose operating segments are carried out through the use of the improved VFO. Given these characteristics, with which spurious signal outputs are reduced or eliminated, in this new radio it is feasible to add a linear that can raise the power to approximately 7 watts, which would adjust to the power conditions described above.

This experienced “clunker” says that for the development and construction of this transceiver, three fundamental aspects were combined: the first, applying the experiences of having built other radio models, to ensure that the new prototype could be built by any radio amateur. with minimal knowledge of electronics, using recycled components and materials. Secondly, he used and adapted parts of the construction schemes of a radio project called LU3DY, from the Argentine Radio Club “Almirante Brown”; and finally, the adaptation of some parts of the traditional Jagüey, such as the VFO board and circuit. Although, as already explained, the radio works, 

Andy Fernández is immersed in the construction of a small linear amplifier similar to the ARARIHNA project, by a Brazilian radio amateur, as well as making final adjustments to what is already a reality: the conclusion and final adjustments of the new CO9BIA 455 Transceiver, a portable QRP device for the 40 meter Band, developed in these times when we must all stay at home, to protect ourselves from COVID-19. 

By Luis Enrique Estrada Hernández (CO2BK) FRC Information System Coordinator 

Circuit details.  

The VFO Board

Here is the web site of the Federation of Cuban Radio Amateurs that describes Andy's work: 

https://www.frcuba.cu/filiales-grupos/la-habana/radio-transceptor-co9bia-455.html?fbclid=IwAR1DptfJdfAS5PSBbyMMUd6zjHo2EA3SHo7hhD1hUPRdtYVF29mKPD8dgPE

And I learned a very useful Spanish word through this:  "Cacharreo" is a Spanish word that means to tinker with something in an attempt to fix, mend, or improve it. 

Thanks Andy!  And thanks to  Trevor for alerting me to this great project.  

The Super Islander Mark IV -- A Cuban DSB Transceiver Made From CFL Lightbulb Parts

Trevor Woods also sent us this report from Arnie Coro.  It is not clear to me what difference (if any) there is between the Super Islander Mark IV and the Jaguey Five (described yesterday).  But the bit about using parts from old CFL bulbs is interesting.  This was something championed by Michael Rainey AA1TJ several years ago.  See: https://soldersmoke.blogspot.com/2009/01/soldersmoke-98.html  

and:

https://www.qsotoday.com/transcripts/aa1tj

April 2010:

Today, I will be answering a question sent by listener Bruno from Croatia... Bruno picks up our English language programs via Internet, but he is now also listening on short wave too. He sent a nice e-mail message asking me about the latest version of the Super Islander amateur radio transceiver, because he wants to build one.

Well amigo Bruno, the Super Islander Mark IV is now on the air, and results are very encouraging considering that it is a 40 meters band transceiver built using recycled electronic components.

The Mark IV uses a totally different approach to the receiver design, and it adds two solid state audio filters.

Amazing as this may sound, some of the electronic components used to make the Super Islander Mark IV transceiver came from the circuit boards of broken or damaged Compact Fluorescent Light Bulbs... and that means that there is virtually an endless supply of those parts.

Here is now amigo Bruno, and amigos listening to the program at this moment, a brief description of the Super Islander's Mark IV receiver module.

It starts with a simple resistive signal attenuator that feeds a dual tuned bandpass input filter.

The filter has a limited bandwidth , chosen so as to limit response to out of band signals... The filter is followed by a cascode transistor radio frequency amplifier stage, that feeds a broadband four diodes product detector.

Low level audio from the product detector goes to the audio filtering and amplifying module, made with discrete transistors, of which several of them are also recycled from the Compact Fluorescent Light Bulbs circuit boards...

This version of the Super Islander, the Mark IV , is radically different from any previous ones, as we have now switched over to a totally low cost solid state design , that can be easily reproduced because it uses very common electronic components and straightforward , easy to adjust circuits.

In our upcoming mid week edition I will describe the VFO, or variable frequency oscillator and the transmitter module of this unique low cost amateur radio transceiver, the Super Islander Mark IV... about the lowest possible cost transceiver that will make possible regular two way ham radio contacts on the 40 meters band using either voice or radiotelegraphy modes.

The Jaguey Five -- The Solid State Cuban DSB Rig -- Circuit Description

Obviously we need a picture of a Jaguey transceiver. 

"Made in Jaguey Grande" 

Trevor Woods found this report from Arnie Coro (SK) CO2KK: 

February 2009: 

Here is now item three in detail: It was quite a long time ago, when I heard about a nice project sponsored by IARU, the International Amateur Radio Union, that was promoting the design of a kit, a simple single band transceiver kit that could be sent in a small air mail parcel to radio clubs in Third World nations which could then deliver them to would-be radio amateurs, and help them build and align the radios... But, unfortunately I lost track of the project, and as many of our listeners may realize there is still a great need of such a project... Past efforts along this line have had some problems, among them the mistaken approach of using of very sophisticated electronic components that in case of a breakdown would be impossible to replace locally; and also, all attempts seemed to try to make the transceiver an ultra- or near-ultra-miniature radio, something that won't help at all with beginners...

So, when I recenlty received an e-mail from Canada, asking what I thought about reviving this great idea, our Canadian amigo asked what we had already done here in Cuba, with our JAGUEY double side band plus CW 10 watt transceiver that went up to REVISION NUMBER 5. , This was the last upgrade, done about three or four years ago, and we named it the Jaguey FIVE, as it generates 5 watts of CW... The Jaguey FIVE was a low parts count, not miniature, easy to build single band transceiver that used readily available components, instead of sophisticated state of the art parts...

In order to please the friend who wrote about this topic, here is a brief, on the air, description of our Jaguey FIVE and by the way, Jaguey is the name of a town, actually it is Jaguey Grande, or big Jaguey, and the Jaguey is a beautiful tropical tree... The original Jaguey transceiver originated in that Matanzas province town in 1982,

The receiver part starts with a simple yet effective RF attenuator, then it feeds a bandpass
filter made of two tuned circuits... we use shielded IF transformers from old TV sets 4.5 megaHertz audio chains... A simple bipolar NPN small signal transistor grounded base amplifier feeds a homebrew double balanced mixer... and we "discovered" quote, unquote, that the antenna balun transformers used in TV sets, the 300 to 75 ohms baluns, had a ferrite core with two holes that makes a wonderful broadband transformer for the double balanced mixer...

We use computer diodes removed from defunct ISA old computer cards and motherboards and developed a very simple test jig to match the diodes... The double balanced mixer is fed on the other port from a simple three transistor oscillator, of which we have two versions, one using three NPN bipolar transistors and the other one using an FET oscillator followed by two bipolars... at the output of the mixer we have AUDIO, as this is a direct conversion receiver, amigos!!!

Now we amplify the audio using discrete components and again we have two versions of audio filters, one with bipolar NPN transistors and the other using a very common operational amplifier IC... The audio power output stage also is available to the builder in two versions, one using discrete components and the other using an integrated circuit audio amplifier that is locally available here in Cuba and produces a booming 2 watts of audio, with a lot of gain and rather low noise! This is the audio IC used by the most popular TV set in use here in Cuba, so we were able to obtain them from the TV repair shops at low cost.

Well, that's why I will describe as a flexible design... again, no attempt is made to make the Jaguey single band amateur transceiver a miniature rig, as miniaturization is definitely not for beginners!!! And following up this description of the receive section of the Jaguey, in our upcoming mid-week edition of Dxers Unlimited, I will describe the transmitter section of the rig,that shares the same variable frequency oscillator with the receiver.... I think that a new more up to date version of the Jaguey transceiver could very well be made available in kit form, with large-sized and easy to assemble circuit boards. The old Version 5 uses three circuit boards, one for the receiver, one for the VFO and one for the transmitter, so the newcomer can assemble just the receiver and start listening to amateur radio communications before having his or her own ham license!!!

You are listening to the weekend edition of Dxers Unlimited coming to you from Havana on the air and on the web at our Dxers Unlimited blog.

----------------------

A video of Jaguey Grande, Cuba: https://www.youtube.com/watch?v=krblz_5o6jU

Earlier posts about the Jaguey on the SolderSmoke blog: https://soldersmoke.blogspot.com/search?q=Jaguey

SolderSmoke Podcast #246: PeteGPT! DC RX, Si5351, Franklin osc, Cuban DSB, Hex beams, uBITX mods, DX, 10 meters, MAILBAG

 

SolderSmoke Podcast #246 is available: 

AUDIO PODCAST: http://soldersmoke.com/soldersmoke246.mp3

YouTube VIDEO: (247) SolderSmoke Podcast #246: uBITX, Hex Beam, DX, High School DC RX, 10 meter SSB Rig, MAILBAG - YouTube

The AI Deep Fake Threat!  PeteGPT!

Hearing Aid info:  I can hear the cymbals in my audiogram adjusted Airpods.

Update on the TJ DC RX project – Several receivers working! https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

Sunil’s company provides Nano/Si5351 combos.  With the KD8CEC software. Very cool.  http://amateurradiokits.in They have a new SSB dual band transceiver – the Airpal.

Mark AJ6CU helping me. Sent me Nanos with KD8CEC software. His uBITX Settings Editor seems very cool. https://github.com/AJ6CU/uBITX-Settings-Editor/releases/tag/V2-beta-1  Thanks Mark.  

Franklin Oscillators. 

Cuban Islander and Jaguey info.  Send more!

Fixing up uBITX 2   How Bill blew up TWO Raduino Nanos. My results with the KB1GMX mods. (see below)

Hex Beam work:  Adding 10 and 15 meter elements.  But now I can hear AM breakthrough from WFAX 1220 AM  (5 kW during the day),  So I made a high pass filter.

Made first contacts on 15 and 10:  Argentina, Brazil, Dominican Republic.

First contacts with both India VU3TPW and China BA4TB.  SSB homebrew.

sBITX news. Taking orders!

Pete’s 10 Meter SSB Project

Mailbag:

--Wes W7ZOI provided great info and analysis on the Franklin oscillator. And lots of great tech info on other topics: http://w7zoi.net/oldtech/ponder.html Thanks Wes!
--Lex PH2LB. uBITX mods. TO-18 Heatsinks. New stickers (see above).
--Kostos SV3ORA and Hans G0UPL about the Franklin Oscillator.
--Listening to HRWB 178: Great stuff, many old friends: George KJ6VU moved to Oregon. Thomas K4SWL on the show.  Ben, an old friend of Pete’s,  mentions John Zaruba K2ZA – the guy who gave me the DX-100. Wonderful connections.
--Thanks to Todd VE7BPO for sending me another AADE LC meter. I need it for the SSSS.
--Nick MONTV planning a 15/10 meter dualband SSB rig. Me too! See video.
--Trevor Woods in W. Australia – The portrait in Artie Moore’s shack. Chuck WB9KZY – Willam Ramsay
--LA6NCA Helge three tube RX. Regen or DC? Mike Masterson WN2A and I discuss.
--Mike WU2D video on Retro QRP rigs – Steve G0FUW discusses Severn rig long in the works –started 1983 and nearly finished!
--Tim Hunkin of Secret Life fame did video with speaker made from potato ship bag. Discussed with Tony G4WIF and others. Also, Tim has an amazing video on cutting holes in metal. On the SolderSmoke blog.
--Bob Crane W8SX will be covering FDIM for SolderSmoke!
--Glen VE3DNL working on a more sophisticated DC RX.
--Craig KC2LFI from the beach on Grand Cayman. FB.
--Steve EI5DD reports We have changed our name - The May Issue of the HAM RADIO IRELAND Magazine, Ireland’s only independent magazine for the Radio Experimenter: https://docdro.id/SHH0VEy
--Mike EI0CL on 15 meters with Dean KK4DAS. FB
--Howard N3FEL of the Penn Wireless Association wants to do a group build of a DC RX.
--Martin LW9DTR in Buenos Aires looking for help with the code for an AD9850
--Todd K7TFC – always helping other homebrewers.
--Really thoughtful message from Kevin WN7Z

uBITX 2

My KB1GMX mods to uBITX 2

Arnie Coro: Jaguey Rig Designed in 1982, More info on the Rig

Jaguey, Matanzas, Cuba

Dxers Unlimited's mid week edition for 23-24 October 2007

By Arnie Coro
Radio Amateur CO2KK

...

My own personal experience with the original JAGUEY direct conversion 

transceiver, designed way back in 1982, is that when used with a well 
designed front end input circuit, those receivers provide amazing 
sensitivity, with signals as low as 1 microvolt easily detected but, 
they do have one drawback, their selectivity or ability to separated 
between stations is very poor. The direct conversion radio receivers are 
used for picking up CW Morse Code Signals , Digital Modes and Single 
Side Band, but they are not good for receiving AM signals, and can't 

pick up FM modulated signals at all...

The original JAGUEY 82 Cuban designed single band amateur transceiver, was tested against a sophisticated and really expensive factory built 

transceiver. The tests showed that our design was at least as sensitive 
as the very expensive professional equipment, registering a measured 
sensitivity of less than one microvolt per meter, producing perfect CW 
Morse Code copy of such a signal. Adding well engineered audio filtering 
to a direct conversion receiver can turn it into a really wonderful 
radio by all standards amigos. 

Radio is a fun hobby, and believe me amigos, there is nothing more 
magical than listening to a radio receiver you have just finished 
building !!!

-----

Peter Parker VK3YE Found a nice description of the Jaguey by Cuban radio Amateur Jose Angel Amador from the BITX40 Facebook Group: 

A translation.  This was apparently in response to someone who thought they'd found a Jaguey schematic: 

"That's not an original Jaguey, that was a simple, single band, unswitched, 5 watt, DSB, kit for beginners with no gear and needing something to put on the license.

Carbon microphone direct to balanced modulator, two stages with 20 dB gain, W1FB/W1CER style feedback, and final with 2 x 2N2102 class B.
The receiver was more like that of the schematic, with a TAA263, easy to get from the FRC in 1978, and headphones. No need for an RF stage: the mixer was overloaded at night with European broadcasts above 7150.
The VFO is also inspired by Solid State Design for the Amateur Radio, a Colpitts with 2SC372 and a low gain feedback buffer with two 2SC372s.
Binocular ferrites were taken from Soviet TV baluns. The conditions of Cuba 1978.
Today I would make an SSB rig with polyphase networks, mixer with 4066,  and VFO Si5351.
The big complication of BitX is the crystal filter, they either get it made, or stick to a recipe, but few have what is needed to measure and tinker with crystal filters.

Arnie Coro CO2KK (SK) Provides More Info on the Islander DSB rig

Peter Parker VK3YE found this message from Arnie CO2KK in the Wayback Machine.  We continue to look for more information on the Jaguey solid state DSB rig. 

Arnie wrote: 

Several years ago an amateur in central Cuba was approached by some of his young friends to help them build their first rig. CO7PR, Pedro, a telecommunications technician for the phone company, had a vast experience both with vacuum tubes and solid state circuits, plus that special gift of designing and building with whatever is available. After a few days, Pedro came out with the "Islander" prototype, a low parts count, easy to build single band transceiver!

Here is the circuit description of that little radio that has provided many cuban young and old, newcomers to our hobby, with their first rig... and the challenge to improve it.

RECEIVER:

It is a direct conversion, YES, a DC receiver made with vacuum tubes. The very thought of having those tube filaments fed from the AC power supply and at the same time having 80 or 90 dB of amplification made me shudder when I first talked to Pedro on the very popular here 40 meter band! You are LOCO Pedro, I told my good friend... CRAZY, those poor kids are going to hear 50 percent 120 hZ hum when they tune across the 7 megahertz band.

Yes Arnie, you are right, it has a little background hum, but by using a small loudspeaker and small coupling capacitors... it's tolerable! The receiver shares, in its original version, the same antenna input as the transmitter output stage, a PI network, but we soon learned to add a separate LC tuned circuit first and latter a bandpass double tuned input filter...PLUS a signal attenuator... a very primitive but effective attenuator... just a 10 k potentiometer!

For an RF amplifier stage the Islander uses a russian pentode, which is the equivalent of the popular TV IF amplifiers of the 50's... looks like a 6CB6, for those of you that fixed TV sets 40 years ago or so.

The 6 "little spider" five, as everyone knows that tube here,has a lot of gain, and it can be kept rather stable by a judicious choice of screen and cathode resistor values.. Noisy pentagrid converter follows!

The 6A2P... a russian 6BE6, was the first tube type used in the Islanders, later some people tried the ECH81 triode-hexode and found it works better.

The circuit of the 6A2P-6BE6 is quite straighforward... a... you guessed right... PRODUCT DETECTOR... fed from the vacuum tube VFO... and providing its audio output to the two stage audio amplifier.

Audio amplifier is made with a triode-pentode tube of which plenty are locally available from defunct TV's... the ECL82 and the 6F4P and 6F5P of east european and russian manufacture respectively provide a lot of gain.

So... that's your receiver.. quite straightforward, works on 160, 80 and 40 meters by just changing the input filter and the VFO injection, it does NOT provide very good selectivity at all, but during the daytime, when the 40 meter band is used for local and regional contacts, it puts those new hams ON THE AIR!

VFO... the big problem amigos!

CO7PR worked very hard to try to make a stable vacuum tube VFO... and he almost made it..

YES, ISLANDERS drift, some not too much, others are not so good, depending on who built the rig, and how close they followed Pedro's advice at first, and Arnie's CO2KK later (as yours truly became quite involved in the project, as soon as I found that it was THE way of getting all those guys ON THE AIR!)

VFO is made with ONE of the 6 "little spider" 5 pentodes... By the way, I am sure you will like to know why the tube is locally known like that... the ZHE letter of the Cyrillic alphabet is something difficult to pronounce to a cuban - or any other non slavic for the matter - and it resembles like a little spider on the tube's carton and... that's why it is not a 6 "ZHE" 5 but a 6 "little spider" five!!!

The VFO cleverly works at one half the operating frequency... and then it DOUBLES frequency at the plate circuit... output is via a link to the pentagrid or hexode mixer depending on which type you use.

BUT... the VFO also has a second output to the transmitting chain.. Well that's the receiver... OH YES... the VFO is fed from a VR tube, a gaseous discharge voltage regulator similar to a VR-150 or VR-105... CO7PR advises to use the VR105, but when building the Islander, special in the countryside, that's a very hard part to find, as old TV sets don't use VR tubes! So people use whichever VR they can find. ZENERS? They are only available locally for 6 to 24 volts, so they can't be used with this rig.

ISLANDER DSB AND CW transmitter circuit:

From the VFO plate circuit, you pick up 7 mHz energy (usually you must wait at least half an hour for that said 7 mHz energy to be stable enough in frequency) and feed two diodes (ex-video detectors from russian TV type D20) acting as what I like to call BALANCED AND UNBALANCED modulator!

When used for DSB, it is certainly a DSB generator... but when you want to work CW, it must be UNBALANCED.something easy to achieve with just a resistor from the +12 volts line and a switch!

The balanced modulator receives its audio from a carbon microphone capsule salvaged from an old telephone, and conveniently connected to same +12 volts with some additional filtering via biggest possible electrolytic + small ceramic dogbone from TV set IF amplifier as RF bypass... no dogbone capacitor there... strange howls on Islander audio as RF leaks into balanced modulator you know.

So dogbone ceramic capacitor is a must! No, disk ceramics are not locally available, so people must use the next best choice... dogbone ceramics in the 100 pf to 5000 pf range, usually rated at 300 volts or so... (that 300 volt rating we learned the hard way, but more about that later.)

The original version of CO7PR's Islander ran with the carbon microphone, no MIC LEVEL control option, as he really wanted to keep things simple... later versions have audio preamps of various designs, and some even have a sort of primitive compressor.. From the balanced modulator the DSB (plus a little carrier leak that is always there) drives the rig's one or two transistor low level RF amplifier, which is made using whatever NPN silicon transistor is available, usually KT315's salvaged from TV's too. the KT315 is sort of a russian version of the 2N2222, so you understand why we use it here!

RF voltage reaches then the grid of an ex-video output amplifier vacuum tube, and there you are... about 2 to 5 watts of either DSB or CW on 40 meters and a new cuban amateur ON THE AIR!

Before I forget... keying... a little chirpy always because of so many interactions between simple circuits, sometimes not too well shielded, first time builder etc.

BUT... ISLANDER is ON THE AIR providing that young kid from the local junior high school or that doctor that always wanted to be a ham, or maybe the fresh out of school electronic technician, with the fascination of their first ever rig. YES, they drift, and some drift badly, when the frequency determining capacitors in the VFO are not too good... (most of the time), as I said they are a little chirpy. and the receiver's selectivity makes working 40 meters at night almost impossible (although some wizards do make nightime contacts at the low end of 7 mHz) BUT. YES, they are ON THE AIR.

Today there are a few Islanders still on the air, and some are even still built brand new (with many of CO7PR's and CO2KK's mods), but the trend is for all solid state rigs centered around CO5GV's and CO2JA's prototype the "JAGUEY," a design that draws a lot from Wes Hayward's Solid State Design for the Radio Amateur, and as of late, with lots of ideas coming from SPRAT, the G-QRP club magazine and QRPp from NORCAL, the Norther California QRP club!!!

In a future posting I will describe the "Jaguey," too.

-------------

More info on the Cuban DSB and AM rigs can be found here:

https://soldersmoke.blogspot.com/2023/04/more-info-on-cuban-jaguey-solid-state.html 

https://soldersmoke.blogspot.com/2023/03/homebrew-am-from-cuba.html

https://soldersmoke.blogspot.com/2023/03/more-cuban-homebrew-from-80s-and-90s.html

https://soldersmoke.blogspot.com/2023/03/schematics-for-cuban-islander-double.html

https://soldersmoke.blogspot.com/2023/03/the-islander-homebrew-dsb-rig-from-cuba.html

https://soldersmoke.blogspot.com/2023/03/needed-more-info-on-cuban-islander-or.html

More Info on the Cuban Jaguey Solid State DSB Transceiver

ZL2BMI Transceiver Layout (not full size here!) 

Continuing our search for information the Cuban "Jaguey" DSB rig, Trevor Woods pointed me to Dick Pascoe's QRP column in the (below) July 1998 issue of Ham Radio Today.  I think the first SPRAT article about Eric Sears' ZL2BMI DSB rig was in SPRAT 83 in the summer of 1995.  This fits well with the sequence described below by Arnie Coro CO2KK. 

I am still looking for a schematic and pictures of the Jaguey rig: If you can help in this, please let me know.  

SolderSmoke Podcast #245: Cuban DSB, DC Receiver?, Can you spot the AI? (Prize), Winterfest Loot, Gina's Podcast, 6BA6 buy, MAILBAG

 

DC RX Example by KK4DAS

SolderSmoke Podcast #245 is available for download: 

Audio Podcast:  http://soldersmoke.com/soldersmoke245.mp3  

Video:  (68) SolderSmoke #245: Cuban DSB, DC Receiver?, AI, Winterfest Loot, Gina's Podcast, 6BA6 buy, MAILBAG - YouTube

Travelogue: Cuba DSB and AM. Jose CO6EC and the Islander. We need more info, especially on the solid state Jaguey rig.

Bill’s bench:

Will the High School DC receivers get finished? Future uncertain. But the project was technically interesting. Great working with Dean KK4DAS. Battling AM breakthrough from Radio Marti. We joked that Dean has been listening to Radio Marti so much that even though he doesn’t speak Spanish, he has noticed an increased urge to liberate Havana.

Audio amps: Harder than we thought. Lots of variation in Hfe of 2n3904s. Oscillations.
Not using feedback amps nor LM386s, nor push-pull. Simplicity is a design goal.

Fixing the tuning (bandspread) problem on the VFO was fun.

Antennas? A quarter wave with ground or counterpoise works well. We tried it. (59) An Antenna for the TJ 40 Direct Conversion Receiver - YouTube
----
Back to work on the uBITX. I chickened out on replacing the predriver with a BFR-106, but then – Just in time Todd K7TFC and his Mostly DIYRF came out with BFR106 boards! TRGHS. I will do the mods on two uBITX transceivers. I even bought a solder-sucking iron for the second job.

Winterfest Hamfest. Big success. Thanks VWS. HERRING AID FIVE! Simpson 260! QF-1, Another Radio Shack DMM, Eamon Skelton’s Homebrew Cookbook, Knobs, SWR meter.
----

SHAMELESS COMMERCE: 

-- Todd’s Mostly DIY RF and the BFR106 boards, and much more: https://mostlydiyrf.com/

-- Become a Patreon sponsor of SolderSmoke: https://www.patreon.com/join/4785634/checkout?ru=undefined

----

Pete's Bench: 

Technical Note: Skype problems. Pete's Skype kept dropping out. Bad in the last podcast (#244). Three minute gap. I was ready to scrap the whole podcast when Dean KK4DAS offered to help. And he is obviously well qualified: https://potomacofficersclub.com/speakers/dean-souleles/ Dean went to work with AI. And he was able to fill the audio and the video gaps. Can you spot the three minutes of AI? Send me an e-mail with the time segment of the AI/Deep Fake portion of SolderSmoke 244. The first one with the correct answer will win a prize. 

SolderSmoke #244:

https://soldersmoke.blogspot.com/2023/03/soldersmoke-podcast-244-pete-is-back-tr.html 

Thanks Dean!

----Interview on his Pete's daughter’s podcast. https://soldersmoke.blogspot.com/2023/03/listen-to-pete-juliano-on-his-daughter.html

-- 6BA6 e-bay buy. Will we see an all 6BA6 rig from Pete?

-- The NCX-5 on e-bay

PETE’S NEW BLOG: https://hamradiogenius.blogspot.com/

Mailbag:

-- A New SPRAT arrived in the mail. PH2LB’s Gluestick on the cover.
-- Will KI4POV – Awesome homebrew – on the blog.
-- Sands, VK9WX listening to SolderSmoke on Willis Island! Wow. 
-- Andreas DL1AJG in Germany continues with the Electronics for Biologists DC RX build.
-- Dean KK4DAS and his homebrew 10 meter DSB rig.
-- Jim W2UO built a Michigan Mighty Mite and made a contact.
-- Dave K8WPE and the E in IBEW. We need new stickers.
-- Bob KC4LB – Surface Mount is SMALL.
-- Bruce KK0S on the Herring Aid 5 Board.
-- Chuck WB9KZY on Nuclear Monopole Resonance very cool video – on the blog.
-- Alan WA9IRS wants a CW editor for his phone. Really.
-- Vic WA4THR also working on uBITX power out improvement.
-- Tobias weighs in on Kludge. As in Fudge.
-- Tony G4WIF notes that when he changes his oil he often removes sludge, not slooge.
-- Consultations with Lexicographer Steve KB3SII.
-- Walt AJ6T says CW operating declined after FCC ruling in 1970s about callsigns.
-- Ramakrishnan VU3RDD now VU2JXN has joined the VWS. An old friend of SolderSmoke. Urged us to launch a blog back in 2008. We announced his daughter’s birth - - now Ram is getting ready to build a DC receiver with her.

Schematics for the Cuban Islander Double Sideband Transceiver (Please Send More Info)

 

Jose CO6EC has been digging up 30 year-old Islander schematics for us.  Thanks Jose.  This one shows a VFO for the Islander.   Note that it runs on 80 meters, but they select the second harmonic at 40 meters.  This was a smart move that surely helped with VFO frequency stability. 

Jose sent this printed circuit board pattern for the VFO.  Obviously they were making many of these rigs. 

Here is the power supply.  Jose reports that the transformer came out of a Soviet Krim 218 TV set.  As a kid, I also pulled a transformer out of an old TV -- I did it to build a power supply for a Heath HW-32A. 

Here is another version of the Islander.  Click on the image for  a better view.  Jose reports that this version was circulating during the time Islanders were being built.  He says this diagram many have been done by Arnie Coro CO2KK (SK), and may have been circulated on the internet. 

Here's the first schematic that Jose sent.  Again, click on the image for a better view. 

I will continue to gather information on the Islander and the Jaguey.  If you have any info please send it to me.  

Here are some earlier posts on these rigs: 

https://soldersmoke.blogspot.com/2023/03/the-islander-homebrew-dsb-rig-from-cuba.html

https://soldersmoke.blogspot.com/2023/03/needed-more-info-on-cuban-islander-or.html

Thanks to Jose CO6EC!  

The Islander -- A Homebrew DSB Rig from Cuba

 

This article, the pictures, and the comments are all so cool. They really capture the spirit of homebrew. Obviously we still need more information on  the Islander and the Jaguey.  If you have it, please send it to me and I will disseminate it via this blog. 

From: https://www.frcuba.cu/filiales-grupos/villa-clara/contra-el-olvido.html  with translation by Google.  

I've been in touch by e-mail with Jose Campos CO6EC (the guy in the picture above).   He sent me this partial schematic of the Islander (we still need the VFO circuit and the RF amplifier) .  Thanks Jose! 

Published: 06 August 2018

Views: 2274

Comments: 6

Remembering

By José de Jesús Enríquez Campos (CO6EC)

Next 2019 will be the 30th anniversary of the first convention of radio amateurs in the province of Villa Clara, in Campismo de Ganuza, municipality of Corralillo, on the North coast, about 100 kilometers from Santa Clara, the provincial capital.

This convention was held on a national basis and colleagues from all the country's provinces participated at that time. We did not reach a thousand members throughout the national territory and most of the radio amateurs worked in the 40-meter Band in Amplitude Modulation Then the Lateral Side Band (SSB) was the privilege of a few and the 2 meters was something rare, which did not yet exist in our environment.

At that meeting, a project for a Tube Transceiver was presented, quite simple, with just six vacuum tubes and a BF310 transistor. It was possible to work in HF in Double Sideband, achieving a greater efficiency than the transmission in Modulated Amplitude (AM). This project became known as the Islander.

In only two printed plates, one for the VFO and another for the TX and RX part, which by the way were printed for distribution, in a company in Villa Clara, due to their easy construction and acquisition of the components (almost all of them came out of a Krin-218 TV), a large number of such equipment were manufactured by radio amateurs from all over the country. Like everything made at home, it always comes up with a little problem that later is necessary with tinkering, correcting it.

I remember listening to an old radio amateur from Havana (whose callsign I don't remember) in a pleasant QSO with another colleague, who jokingly said, "... some "Bugs" have now appeared in the band, called Islander, which is worse than the invasion of the Vikings…”, which gives an idea of ​​how many were built at that time, when if you wanted to make radio, you had to manufacture it, something unusual in these times.

As soon as we saw the project we decided to build it, because at that time we had an AM “transmitter” with modulation by “Carrier control” with four tubes, a 12AX7 preamplifier; an ECL82, as a modulator, with cathode output to the final tube Screen grid, a 6DQ6 and a 6BH6 as VFO; and to receive, an old Russian receiver from World War II.
 
 We got involved in the construction and improvements of the project and we managed, with some changes, to improve its performance and quality, because among the modifications to the original, we added: 

 -A switch, with which you could change the transmission mode to DSB -CW-AM.
-A "Pi" Filter at the input of the RX, which considerably improved its quality.
-An automatic volume control, because since it did not have AGC (Automatic Gain Control), when someone nearby came on, it would break your speaker.
-A filter for the microphone input, which improved the quality of the modulation.
-A final power stage, with a 6146B, with 750 V on the board, for about 70 W of  output, taking advantage of the 6P15P as Driver.
-The chassis was built from scratch using aluminum trays that were sold at the hardware store for “four pesos” each and that were special for making cabinets for these purposes.

After the construction was completed in one afternoon, with Reinaldo Martínez Domínguez (CO6UK), from Manicaragua, the balanced modulator was adjusted, since the good transmission of this type of equipment depends on the relationship between the amount of RF and audio that are mixed At that stage, it took us a long time to adjust, until Reinaldo with his expert ear told me, “leave it there, don't touch it, it's 99% complete”.

There were many international contacts that I was able to make with this very simple equipment, with very good reports, many of them with Europe, the American continent, that was very normal, since the propagation conditions in those years had nothing to do with the today, you could do half the world in AM, with about 100 W.
 
Many colleagues at that time asked me what equipment I was using.  When I told them it was an Islander, they asked me to send them the plans of the improvements made, they were many modified plans, mimeographed.
 
Perhaps the youngest do not know what that was and the photos taken by colleague Joel (CO6JC) that helped to illustrate the distribution of the components in the chassis, were sent to radio amateurs from the different provinces, in the interest of contributing modestly to migrate from AM to the Double Side Band, today it is a rarity to listen to someone on AM, there are already few who appear in Double Side Band, which shows that we have developed in these almost 30 years, despite the difficulties, which We went from just under a thousand to about 8,000 throughout the country today.

From time to time, a colleague in the 40 meter Band, from another province, has told me that he still keeps the plans and photos that were sent to him at that time, or as "Kike" (CO6GO) that he still has a Islander as a relic.

Ours passed away a long time ago and part of its components went to other projects, thanks to Joel (CO6JC) there is a graphic record of it, and that at that time I had hair, which I have lost in these bustles.
 
With this brief comment, we only want the new generations to know what radio amateurs were like in those days and the older ones to remember it.

Nothing, to remember is to live again.

Here he left you some images.

• (co6ec) Jose de Jesus Enriquez Campos

  Monday, 06 August 2018 19:30

  The first Image was the prototype presented at the Ganuza meeting, the rest of the photos were the ones we built with the improvements, and the photos and plans were sent to many colleagues, the colleagues who went to that meeting will remember, well, they still have to there are many left, because that was almost 30 years ago,
  greetings CO6EC

• (co8zz) Raul Verdecie

  Monday, August 06, 2018 23:12

  Magnificent photographs!!!... They seem to have been taken today with some digital "super camera"!!!
  Really, from what I can see now, the CO6EC Islander was the perfect example... mine (my first radio and built by me) was also made like this, with the plates that the FRC sold and it was good, but very ugly ...HI... The AGC worked wonderfully as it came, I don't know if Jose's improvements were later! With it I made my first hundred or so entities only in 40 meters / CW (between 7,100 and 7,150) when it was CL8ZZ. I gave it away so that someone would have their license and now I regret not having kept it... I would have liked to show it now to those who regret not having a radio!!!

• (co8zz) Raul Verdecie

  Monday, August 06, 2018 23:43

  Ah, I can never forget those headphones!!!... my external hearing aids (read ears) are much smaller today thanks to them, they exerted tons of force on the operators' skulls!!!

• (cm6vml) Vidal

  Tuesday, August 07, 2018 23:40

  Very good article, I hope that one day, with a good teacher, I can build my own team, congratulations Jose, regards Vidal.

• (co7wt) Pavel Milanes (CO7WT)

  Wednesday, August 08, 2018 09:52

  Sure...
  
  My first radio and with which I got my CL7WT license back in the 90's an ISLANDER, like that in capital letters.
  
  I remember that the CL only had a small 40m segment (like now) and that it was full of broadcasts as soon as the afternoon fell, it was an odyssey to speak on the radio... you had to find a "little hole" between the Broadcastings where it wouldn't bother you " a lot" to be able to talk.
  
  I remember that the old CO7OC (he is no longer a radio amateur) and CL7HU (now AC7HU) helped me build it with a board I bought at the radio club. I took almost all the valves from the deceased KRIM 218, then I found a store in Camagüey that sold idle things from the workshops...
  
  Turns out they had such a large inventory of "idle" tubes that they couldn't put it on the counter...they let me through to the warehouse...huge...stack of tubes, if I remember correctly I ended up with Chinese or Japanese tubes that they were more sensitive in the receiver... the driver went from a 6P14P to a more robust 6P9, by the end that was a humble 6P44 it became two 6P7s that were a Russian version of the RCA 607 if I remember correctly... in the end it had like 80W.
  
  It goes without saying that when I said on the radio that there were valves in that place "they flew"....
  
  The VFO was the one from the Jagüey, not the original from the Islander, I never knew about the AGC modifications.
  
  I would like if someone has the plans with the modifications to send them to me, just for nostalgia...
  
  My email pavelmc@gmail.com
  

• (co2jc) Carlos Alberto Santamaría González

  Monday, August 13, 2018 00:21

  Brother, your article is very good, because of the nostalgia and also because it talks about what we radio amateurs like: tinkering. I didn't have an Islander because what I started with in 2000 was a Polosa to which two colleagues helped me adapt it with VFO for 40 and 80 m. But I talked a lot with colleagues who did it with an Islander or a Jagüey and participated in the Rueda del Behique that I started in the 80 m. Others in the Hurricane Wheel that started a little later and were heard well. As you well say, the propagation at that time had nothing to do with what it is now, but it was very good to listen to the colleagues who came out with the equipment they had built. Thank you once again for your article. CO2JC