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.