10 Meter Quarantine QSOs near Boston -- KC1FSZ's Peppermint 10

Hi Guys:

I hope all is well.  Thanks for the more frequent episodes!

I’ve not submitted anything lately but I’m still doing a lot of building.  Over the last few weeks I’ve been working to get myself on 10 meters.  There is some good local activity up here in the Boston suburbs on 10.  The result of this effort is the next in the Peppermint Line of high-performance radio products for the discerning operator: The Peppermint 10.  This rig uses digital VFOs and puts out about 12 watts on a good day.  It works in conjunction with a direct-conversion receiver that has been modified for 10 meters.  The details are described in the write-up (see link):

https://mackinnon-public-web.s3.amazonaws.com/peppermint-10/index.html 

73s,

Bruce KC1FSZ

Shortwave Dials -- Exotic Locations -- Hong Kong! Berlin! Springfield? Schenectady?

Click on the picture for a closer look. 

No offense to the birthplace of Homer Simpson, but Springfield?  And Schenectady?  This dial glass is all that remains of a shortwave receiver used by my wife's grandfather in the Dominican Republic. 

Many years ago the Boatanchor enthusiasts had a very informal "dial lights" competition.  Which receiver cast the best glow from its dial lights.  (I think my HQ-100 was the best.)

The dials of many old shortwave receivers have recently started to show up on the Shortwave Listening group on Facebook.  Some have some very exotic foreign locations.   Perhaps we should launch a similar competition:  Which SW receiver dial has the most exotic foreign locations? 

   

Applied Sciences Workshop Tour

Applied Science -- Electrical Impedance Tutorials

Part 1 appears above, Part 2 is below. 

Ben Krasnow has a KNACK for explaining technical things.   I liked his videos on impedance.  At the end of the second video, he said he'd do a third one that would focus on impedance in coaxial cables.  But I couldn't find it on his channel.  I hope it was made -- this is very interesting and useful.   

Ben's YouTube channel is here: https://www.youtube.com/user/bkraz333

Listen to Homebrew-to-Homebrew Quarantine Contact with Glenn KU4NO on his 37 year-old Homebrew SSB Transceiver

This was really amazing.  I had been feeling guilty about not getting on the air much during quarantine.  I mean, we have these airwaves and we have the gear, right? Shouldn't we be more social, more friendly and get on the air more?  I tried yesterday with marginal results (conditions were poor).  I called CQ on 40 SSB this morning -- nil, except for one grumpy guy who said I was splattering on his morning coffee clatch. Then I heard KU4NO calling CQ.  I did not recognize the call.  But when I told him I was on a homebrew transceiver, he matter-of-factly sad that he too was on a homebrew rig.  When he started to describe it  (see below), it all came back me.  His is one of the most soulful of homebrew SSB rigs.  And I realized that it may also be THE OLDEST HOMEBREW SSB RIG STILL IN USE IN THE WORLD.  (If anyone knows of a homebrew SSB transceiver older than 37 years and still on the air, please let me know.)  This was exactly the kind of contact that I needed.  TRGHS. 

Glenn put out a lot of homebrew wisdom.  He said a lot of inspiring things.  (He did also at one point talked about wanting to shoot his plasma TV, but that's understandable.)  So I recorded most of our contact.  (I have his permission to put it on the web).   

You can listen to our contact via the YouTube video above.  

For my report on an earlier contact with Glenn click here: 
https://soldersmoke.blogspot.com/2018/07/a-rig-with-maximum-soul-5-band.html

So, it is worth it to get on the air.  They are rare, but people like Glenn are out there, running very interesting rigs. And when you find them, you feel like you've hit the jackpot. 

Thanks Glenn! 

SolderSmoke Podcast #221 is available -- Quarantine Rigs, Phasing, SWL, Parts Suppliers, Mailbag

Q-31.  "Roll-bar" on cap.  Note RGS316 coax between stages. Country markings on tuning dial

SolderSmoke Podcast #221 is available: 

25 April 2020

http://soldersmoke.com/soldersmoke221.mp3

Obviously no travelogue.   QUARANTINE.  SITS.

Good news:   Lawyers at Dewey Cheatham and Howe report that SolderSmoke will NOT be taken off the net for brazen promotion of the S-38E receiver.

Also some good news on the FT8 vs. FT-FAKE issue.  That report itself was fake.  

PETE’S PROJECTS:

Phasing SSB

And what’s this about a tube CW rig?

Dean KK4DAS builds Pete’s Simple SSB rig. Quarantine Rig: The Furlough 40.  See: https://kk4das.blogspot.com/

SHAMELESS COMMERCE DIVISION:  NEW AMAZON LINK IN THE UPPER RIGHT SIDE OF SOLDERSMOKE BLOG. .

BILL’S BENCH:

QUARANTINE PROJECT:    Q-31 AM SW Receiver.  April 4 through April 19.   15 days of fun.   Learned a lot. 

Need to pay attention to total gain.  Need to measure.   Not always easy.  My resistor-based technique.

AM detection can be more difficult than SSB/CW detection.  Germanium diodes make a big difference.

But…I don’t have to build a BFO, because these signals bring their own beat frequency.

455 CAN BE PROBLEMATIC AS AN IF – image response, making impedance matching transformers tough at those low frequencies.   But WIDE filters available.  

LM386 AF chip make a LOT of audio.  Hard to reproduce these great results. 

Great stuff you can listen to on 31 meters (9.4 –10 MHz):

n  DX WaveScan

n  WRMI Rock and roll

n  VORW music show

n  Radio Nacional De Espana (Madrid)

n  China Radio International  soap operas and Confucius philosophy lessons.

n  China Radio International Chinese Lessons.

n  Radio Greece

n  Radio Republica (France)

n  Radio Havana Cuba

n  Radio Saudi Arabia

n  WBCQ – They advised listeners to fix up an S-38 during quarantine! !!!!!!!

n  WWV

SHOPPING BAG -- THINGS TO GET:

-- Great source for hardware (screws, nuts, bolts and more):  McMaster-Carr   https://www.mcmaster.com/ 

-- Thermax RGS316 coax.   Great stuff.   Thanks Jim  In some ways better than Belden 1671A https://soldersmoke.blogspot.com/2012/03/murphys-whiskers-shaved-with-belden.html

-- Copper Clad board:  Pete’s boards use CEM 1. CEM 1 is low-cost, flame-retardant, cellulose-paper-based laminate with only one layer of woven glass fabric.

https://www.ebay.com/itm/18-pcs-Copper-Clad-Laminate-Board-Single-Sided-4-x-6-CEM-1-060-2-oz/311756276147?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

-- BEST TEST LEADS: https://www.ebay.com/itm/BEST-TEST-LEADS-PERIOD-Hand-Soldered-MINI-CLIP-Version-32-16AWG-Ultra-Flexible/233519356767?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

NEED/WANT: 

-- Thermaleze magnet wire.  First encountered in QRP GUYS EFHW tuner kit.  Very FB

http://www.amidoncorp.com/thermaleze-coated-magnet-wire/

Resistor kits

NP0 cap kit

Replacement Iron for XTRonic 4000 Iron.

RIGOL PROBES Why do we burn through so many of these?

MAILBAG:

-- Eric 4Z1UG Episode 300 Special

-- Farhan working on ventilators. Special thanks to Dr. Gordon Gibby KX4Z. 

-- Jonathan-San working out of new shed in Seattle

-- Grayson reminds us of the Fran Lab: https://www.youtube.com/channel/UCMLgHbpJ8qYqj3CkdbvC0Ww

-- WRMI likes SolderSmoke

-- Peter VK2EMU continues to build his amplifier.  But it is NOT for 50 MHz.  It does have 6 different meters on the front panel.  But it is not a 6 meter rig!

-- Rich K7SZ – “now look what you’ve done”   Fixing up an S-38

-- Rich WD3C  Provided some great SWL links:

https://www.short-wave.info/ if you move the green dot to your location it will predict what the signal strength would be at your location and will also allow you to search by station, language, frequency, etc. 

Thomas Whitherspoon, https://swling.com/blog/  Another, https://shortwaveschedule.com/ and of coarse https://www.hfunderground.com/board/index.php all the pirate broadcasters show up here. 

-- Paul KL7FLR amazing S-38E diagnosis from afar. Paul's toroid tool (more to follow on this). 

Pete's Quarantine 6V6 Rig

Quarantine Search for Zombie Satellite in Geo-Synchronous Orbit

Nice two minute audio report:

https://www.npr.org/2020/04/24/843493304/long-lost-u-s-military-satellite-found-by-amateur-radio-operator

Scott Tilley is VE7TIL

The NanoVNA

Jenny List has a good article on Hack-A-Day about the NanoVNA.  

The ability to measure impedance would be very useful. 

https://hackaday.com/2020/04/23/so-you-bought-a-vna-now-what/

WA7SKT's Al Fresco DSB Rigs

Loren WA7SKT wrote: 

Got the balanced modulator and first RF power amp board mounted today for my 20 meter DSB transmitter (above). Still have to build carrier oscillator and final RF power amp boards yet. Coax with BNC connector is carrier osc input to bal mod. As is puts out 8.5mw into 50 ohm load.

Audio in through 2N3904 emitter follower to SBL-1 balanced modulator. Rf out to a 2N4401 Class A RF amp. Will have a final RF power amp stage and to the lowpass filter. Targetting 250mw output max for WSPR. Will add the 2N3904 Colpitts oscillator with tuned collector for carrier oscillator. Power supply will be 9 volts and 12 volts.

This is part of my fun in eventually building a 20 meter SSB transceiver. I am not interested in anything multi-band. This is my second DSB transmitter. First is larger and uses Si5351 for carrier oscillator.

I also plan on building a WSPR transmitter using an Arduino and Si5351 synthesizer so I dont need my PC.  There is a frequency shift program for Arduino to control Si5351. I use Si5351 now for VFO’s. My first WSPR transmitter uses one just for carrier oscillator.

Loren's First DSB Rig

I like Loren's self description on Twitter: 

Jonathan-san (Our Man in Japan) Now Melting Solder in Seattle

Got a nice note from Jonathan W0XO.  He and the family  have relocated to the Seattle area.  Here we see Jonathan at work in his new shed/shack.  It looks great. 

Long-time SolderSmoke fans will remember Jonathan from his previous life in Asia. See: 

https://soldersmoke.blogspot.com/2016/04/from-vietnam-to-washington-dc-jonathan.html

Please Listen: Something Wrong with Spanish National Radio Signal?

I've been getting back into shortwave listening. One of my favorite stations is Radio Nacional de Espana (Spanish National Radio) from Madrid.  It is very strong here on 9690 kHz starting around 1645 Eastern Time, 2145 UTC.  

If you can, please listen to this station and let me know if you hear any technical problems with the signal.  Please let me know what you hear.  Does the signal sound OK.  Any problems? 

  

Dean KK4DAS Builds SSB rig, Makes First Contact.

You can almost see the excitement in the notes (al fresco!)  of Dean KK4DAS.   He made his first QSO with a homebrew transceiver this week.   Not long ago Dean was taking his first tentative homebrew steps with a Michigan Mighty Mite.  Wow, he has made great progress.   

Read all about it on Dean's blog:  https://kk4das.blogspot.com/2020/04/furlough-40-first-contact.html

Congratulations Dean! 

DX WaveScan

I heard this program this morning on my Q-31 receiver.  It was on WRMI 9955 kHz at around 1330 UTC.   

It reminded me a lot of the DX listening program of HCJB.   Good stuff. 

You can listen to the programs on-line at:  https://awr.org/program/engmi_wav/

Q-31 Quarantine Receiver -- All Boxed Up, Almost Done

Almost done.  A few odds and ends remain, but now I have all the circuitry in their boxes. 

As I was taking my walk the other day I was thinking of how I didn't have to build a BFO for this superhet. That's because the signals coming in on this rig bring with them their own BFO signal (the carrier).  

Q-31 Quarantine Receiver -- +30 db and a Germanium Diode Help a Lot (video)

Today I added two additional stages of IF amplification.  This added 30 db to the receiver's total gain.  That helped a lot.  I also discovered that Germanium (1N34A) diodes work a LOT better as AM detectors than do silicon diodes.   This receiver is starting to sound decent.  Currently listening to the VORW program on WRMI Miami.  

Walter's VFO

Main VFO board under plastic -- buffer board off to the right

There is a lot of tribal knowledge in this short article by Walter KA4KXX.  (The most recent issue of SPRAT has a picture of a SPRAT cover from more than 30 years ago, announcing an article by Walter.  OM has been at this for quite a while.)  Walter's advice is similar to that of Doug DeMaw, especially on the air-core coil.   FB Walter,  thanks for sharing.  

Regarding the last line in Walter's article, please direct any complaints about drifting analog VFOs to Peter Juliano.  He will be delighted to receive these complaints, and will promptly provide all correspondents with very succinct advice on how to overcome the instability.  

My Way to a Low-Drift Analog VFO, by Walter KA4KXX

I recently built a digital VFO (from a QRP Labs Kit) to see what everybody is talking about, and it has been quite handy for my first two-band homebrew transceiver, but by the time one adds the low pass filter, a low-level RF amplifier to boost the weak output, a 5 VDC regulator, and a hefty +12VDC power line filter to the beast to keep the digital noise out of the rest of the radio, for a single band project I still prefer a low-drift analog VFO.  

My approach to minimizing drift is very simple and works well for a VFO range of 3 – 7.3 MHz, which is all that is needed for the 20 to 80 Meter bands, either direct conversion (adding a doubler for 20M) or single conversion with approximately a 10 MHz IF.  

First, see my schematic (adapted from Small Wonder Labs 40+ transceiver, original BITX40 Analog VFO, and other sources) and wind an air core inductor with stout magnet wire such as 24 or 22 AWG.  Use a thick, rigid plastic form of a diameter so that you need about 12 turns, and single coat with water-based sanding sealer, Q-dope, or similar.  Use hot glue to mount the coil firmly to the single-sided circuit board, and build a cover of some type, especially if the radio is to ever be used outdoors.
   
Second, all the VFO capacitors (except power supply bypass) should initially be the modern C0G type, which can be obtained from Mouser (such as TDK FG28C0G1H681JNT06 or the like), which I trust more than those labeled NP0.

Then, power up the VFO and tweak the coil, tuning arrangement, and range capacitor to get the frequency range you desire.

Next, monitor the drift from a cold start to see how fast it is moving as it warms up, and whether it stabilizes nicely (my goal for SSB Phone use is less than 20 Hz drift during any 10 minute period) after 10 – 15 minutes maximum.  If it does not stabilize to your satisfaction, then start substituting polystyrene caps for the C0G units one at a time until you are happy with the performance.

[Also remember that a stable BFO is important as well, and if you use the BITX 40 crystal oscillator design, I recommend installing a dedicated 78L09 power line regulator.]

If you build this VFO at the higher (7 MHz) frequency end, just change the inductor value to about 0.5 uH, with everything else about the same, but expect to do more tweaking to get stability, and the warm-up time may be closer to 15 minutes.  After years of experimenting, this is what has worked for me.  If it works for you, please send me an email (see my QRZ page) of thanks.  If not, file a complaint with Soldersmoke. 

Q-31 Quarantine Receiver -- First Signals (Video)

It still needs a lot of work, but today it pulled in its first shortwave signals.  See video.

Quarantine Rig Q-31 -- Putting the Stages Together (Most of Them)

I've been recording short videos on my progress with the Q-31 Shortwave AM Quarantine Receiver.  

Yesterday was a bit of a milestone -- I put five of the six sub-assemblies together and did some testing.  You can see the video above. 

All the other videos are on my YouTube site: 

https://www.youtube.com/user/M0HBR

Please subscribe and give me a "thumbs up." 

SITS!  Stay in the shack!  Flatten the curve.  Hang in there.   73  Bill

Other Kinds of Knack: Woodwork Wizard! (video)

This guy has some amazing tools, and even more amazing skills.  I find it inspirational to occasionally take a look at other kinds of workshops.   Check it out.  Video above. 

Along similar lines, the young Englishman Leo was in Washington state with his girlfriend when the lock-down and travel bans kicked in, so his work on Tally Ho (and his videos) continue.  See:
https://youtu.be/zXV0ywqj7zY

SITS! or Stay in the wood-shop! 

Brace Yourselves: DK7IH's New Transceiver -- The Gimme Five

Lock-down is bad enough, but now we will also have to cope with the feelings of homebrew inadequacy that Peter's rigs always cause.  But look on this as an opportunity for inspiration.  Peter once again raises the bar.   

https://radiotransmitter.wordpress.com/2020/04/11/gimme-five-reloaded-a-compact-5-band-qrp-ssb-transceiver-in-smd-technology/

This looks like it is the first in a series of blog posts. Just what we need in quarantine.   Thanks Peter.  

Videos on the Q-31 Quarantine AM SW Receiver Project (and some pictures)

I've been making some short, stage-by-stage videos of my Q-31 receiver project.  So far I have seven videos.  They are here: 

https://www.youtube.com/user/M0HBR/videos

Please subscribe to my YouTube Channel.  And give me some "thumbs up" if you like the videos. 

Thanks.  SITS!  FlattenTheCurve!  73 

Pads from Pete, toroids from Farhan

The diode ring

Altoids-sized tins will hold the circuit boards

Stay In The Shack -- Or in the front yard. 

Blog -- "Chinese Electronics Products Tested"

I was looking for information on my  FeelTech FY3200s Signal Generator.  I came across a very informative blog; it covers a variety of other Chinese gear and parts.  

Here is the Feeltech FY3200S article: 

https://chinese-electronics-products-tested.blogspot.com/p/fy3200s-function-generator-tested.html 

Here is the home page of the blog: 

https://chinese-electronics-products-tested.blogspot.com/

And here is backround information on the author: 

Thanks Jos! 

WB9IWT's Quarantine Mighty Mite and N3FJZ's "Hiram Percy Maxim Recognition Factor"

Leif WB9IWT has, during the emergency, been working on a Michigan Mighty Mite (See pictures above and below).  FB Leif.  

But also check out the very astute comment from Rick N3FJZ (below) .  I am, of course, all in favor of the HPMR Factor.  Almost all of my rigs would score quite high.    Others, I know, would seek a low score.  To each his own.  This is all for fun.  

Leif,

Great work.  If a ham from the 1920's were to see this rig, they
probably wouldn't recognize the actual components right away (but
knowing hams, they would no doubt figure it out), but the breadboard
layout circuit flow would be immediately recognizable; e.g. the plug-in
crystal, the coil, binding post.  The transistor and variable capacitor
may baffle them at first, but seeing there are three leads on the
transistor would start to give them clues.

That's the cool part about analog discrete component radio, no matter
how many years go by, and the appearance and size of the actual
components change, the physics of what's going on at the electron level
stays the same (SDR not withstanding).

I guess this could be a litmus test for us analog radio builders.  It
could be called the "Hiram Percy Maxim Recognition Factor" or "HPMR
Factor" with a range of 0 to 1.  After you  build your rig, take a look
at it and pretend that you could present it to Mr. Maxim and the more he
could understand the circuits, components and circuit flow on his own,
the closer to a factor of 1 your radio would achieve.  For example, an
SDR might only achieve a factor of .1 or even maybe 0, where as your rig
may achieve a factor of .8, and one of your crystal receivers would
definitely get a 1.

Someone could even workout a check list or formula where you would add
or subtract some fractional numeric values for each component you used;
e.g. you would subtract some value for every IC chip, microprocessor or
LCD display you use, and add some fractional value for each hand wound
coil, vacuum tube/valve or open air variable capacitor, et cetera.

Fun to think about.

Keep building.

Rick - N3FJZ

Quarantine Reading: Tribal Knowledge: Two Gems from Pete Juliano N6QW

WB9FLW recently reminded us of two very useful documents that have been kind of buried on one of Pete's web sites.   I think these documents are just the kind of thing we all need during these dark days of quarantine.  So just sit back, StayInTheShack,  and soak up tribal wisdom from the Wizard of Newbury Park.  

http://www.jessystems.com/Homebrewing%20for%20QRP%20SSB.pdf

http://www.jessystems.com/How%20To%20Stuff%20A%20Junk%20Box.pdf

Here is the message from WB9FLW that unearthed these gems:  

Morning Pete,

Three cheers for posting the Simple SSB Transceiver as a possible project during the pandemic lockdown.

Suggestion, folks that are new to your Website may not have seen some of your earlier posts especially on jesssystems.com. 

"Homebrewing For QRP SSB" is a gem and a great lead in to the simple SSB Transceiver project.

http://www.jessystems.com/Homebrewing%20for%20QRP%20SSB.pdf

There is a lot of wisdom in those pages, perhaps you can add a link for those interested in building the rig.

"How To Stuff A Junk Box" is good as well.

http://www.jessystems.com/How%20To%20Stuff%20A%20Junk%20Box.pdf

Hope you and the family are doing well.

Pete  WB9FLW

ZL2CTM Charlie Morris on "QSO Today" with Eric Guth 4Z1UG

Eric Guth 4Z1UG had a really nice interview with our friend Charlie Morris ZL2CTM.  Charlie shared with Eric a lot of wisdom about how to homebrew radio gear.  I especially liked Charlie's comments on keeping most of his rigs on the wooden prototype boards.  He said something important when he talked about the benefits of taking a break from a difficult problem, then coming back to it with a rested and refreshed mind. I noted, however,  that he said most of these frustrating problems have to do with software.  

I got got several chuckles out of Charlie's comments on the difficulty of building stable analog LC VFOs (here he seemed to be channeling our good friend Pete Juliano).  I chuckled because as I listened I was happily building the analog LC VFO for my Q-31 Quarantine receiver.  The centerpiece of this project is a variable capacitor that Pete gave me;   Pete took it out of an old  Galaxy V transceiver.   Believe me guys, no rotary encoder could possibly look as nice or have as much soul as that capacitor from Pete, with all its gears, reduction drives, and anti-backlash mechanisms.  It even smells of machine oil.  Call me a Luddite, but I will stick with the coils and capacitors.  

Listen to the interview here: 

https://www.qsotoday.com/podcasts/zl2ctm

Thanks to Charlie and Eric. 

The Low-Cost, Open Source COVID-19 Ventilator that Farhan is Helping to Build (Video)

While many of us are just trying to pass the time by building Quarantine ham radio rigs, our good friend Farhan VU2ESE has been hard at work on a really serious project:  He has been working out how to use an Arduino microcontroller as the electronic core of a simple ventilator that could save thousands of lives in the current crisis. See video above. 

Here is background info on the project (from ARRL): 

03/23/2020

Amateur radio volunteers from around the world have volunteered to assist University of Florida Professor Sam Lampotang and his engineering team in their quest to rapidly develop an open-source, low-cost patient ventilator that can be built anywhere from such commonly available components as PVC pipe and lawn-sprinkler valves. The amateur radio volunteers are developing Arduino-based control software that will set the respiratory rate and other key parameters in treating critically ill coronavirus victims.

Multiple volunteers responding to a call for help from Gordon Gibby, MD, KX4Z, included noted software developer Jack Purdum, W8TEE, and  uBITX transceiver maker Ashhar Farhan, VU2ESE. University of Florida physicians are working to address the critical legal aspects as the design moves closer to fruition.

The ventilator’s valves would precisely time compressed oxygen flow into patient breathing circuits under Arduino control, allowing exhausted patients with “stiff” lungs impacted by viral pneumonia to survive until their body can clear the infection. The software design team is also adding simple features such as an LCD display, encoders to choose parameters, and watchdog safety features. -- Thanks to Gordon Gibby, KX4Z

It is important realize that in countries around the world, many victims of COVID-19 will have no hope of getting anywhere near the kind of $50,000 ventilators found in U.S. or European hospitals.  That is one of the things that makes this low cost, open-source project so important. 

More details on the project here: 

https://github.com/afarhan/osventproto

Please pass the word on this project.  Please forward on Facebook, Re-tweet, etc. 

Quarantine Project: An AM Receiver for the 31 Meter Band. The Q-31.

During this StayInTheShack (SITS) emergency, it is good to have something to work on.  I decided it would be best to try to build something using only items currently in my parts collection.  I've been getting into shortwave listening again, and I've discovered that the 31 meter band (9.4 - 9.9 MHz) is my favorite. Thus the "Quarantine On-Hand 31 Meter AM Receiver."  A big part of the inspiration for this project comes from the AM receiver of Paul VK3HN. 

I propose that we all designate rigs built during quarantine as "Q" rigs.  This will be the Q-31. 

I had an old chassis on the shelf.  It held my WSPR DSB rig in Rome, and various other projects over the years.  It has so many holes in it that it looks like it has been used for target practice.  

A while back Pete N6QW sent me this really magnificent variable capacitor with at least two reduction dries and an anti-backlash gear.  I've been looking for a project that will allow me to use AND display this beautiful part.  It will be the main tuning cap for the Q-39. It will stay -- like the tubes in the rigs of days-gone-by --  above the chassis. 

While in London many years ago I picked up an old regen receiver at the Kempton Park rally.  The parts are still in my junk box.  A very nice 1.7 uH plug in coil (with socket) was there.  That will be the main coil in the Hartley Oscillator that will be the VFO.  I will add a few turns for the feedback coil (see circuit diagram below).  I wonder of that Eddystone coil was around for the Blitz? 

On the recommendation of our old friend Rogier (originally PA1ZZ), a few years ago Elisa got me a set of grey Altoids-sized metal boxes.  I will have three of these atop the target-practice chassis (they will provide shielding and will cover up the holes): 

-- One will hold the bandpass filter (designed with the Elsie program) and the mixer (probably diode ring, with transformers from Farhan). 

-- One will hold two IF amps with a 10 kHz 455 kHz IF filter between them (thanks to Bruce KK0S for the filters). 

-- One will hold the AM detector and the AF amplifiers. 

-- A fourth box will be under the chassis and will hold all the powered parts of the VFO circuitry.   I base my VFOs on this simple circuit from page 34 of Solid State Design for the Radio Amateur: 

This quarantine looks like it is going to last a long time, so it is best to take your time on projects like this.  I might work on the VFO today.  No need to rush... 

I am shooting videos as I go along and will at some point start putting them up on my YouTube channel.  

So, I suggest that any of you who are feeling bored and confined (that would be almost all of us) fight back by launching a Quarantine "Q-Rig"  project.   Send reports to me -- I will try to put them on the SolderSmoke blog. 

Remember:  StayInThe Shack!   #SITS!  #flattenthecurve. 

73  Bill