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Saturday, April 25, 2020

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


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.  


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/



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


-- 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.


-- Thermaleze magnet wire.  First encountered in QRP GUYS EFHW tuner kit.  Very FB
Resistor kits
NP0 cap kit
Replacement Iron for XTRonic 4000 Iron.
RIGOL PROBES Why do we burn through so many of these?


-- 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


  1. My trials of woe, 4 or 5 IRF510 schematics, and 30% efficiency, 15 watts DC to make 5 watts of RF. What can I reasonably expect? Ed KC8SBV

  2. Man you have to love that juliano blue color!

  3. Bill your podcast archive is way out of date. I have been robbed twice in the past 6 months so have lost the local archive on my laptop that I was slowly working through.

    1. Mark: Sorry to hear about your trouble - that's terrible. I will try to update the archive, but I only do this from time to time. In the meanwhile, you can get all the back episodes through this blog page -- just click on SolderSmoke Podcast in the column on the right hand side of this page. Let me know if you have any trouble. 73 Bill

  4. Hi Bill,

    Believe the Xytronics 210ESD soldering iron may be a generic replacement - https://www.howardelectronics.com/soldering/handpiece-parts/xytronic/210esd-en/

    de Henrik VK2HHS

  5. Hi Bill!
    I was listening to the podcast this evening, and was pleased to hear you talk about the neutralization of a sideband in a direct-conversion radio by essentially building two receivers and phasing them. I'm on that EXACT page in K0IYE's "Crystal Sets to Sideband". I took the PDF of that file and sent it to my Kindle account, telling the server to convert it to Kindle format. That way, I can pick it up and keep reading just about anywhere, since I can read it on my phone, on my PC, on my Chromebook, and on any of my Kindles. (Yes, I have 3 of them...a Touch I got for my Mom, but inherited when she passed, a Fire tablet, and the newer Paperwhite.) I love being able to, in essence, carry a whole library with me everywhere I go. I can pull up "The Art of Electronics", "Electronics from the Ground Up", "Electronics for Inventors", and this nice book called "Soldersmoke".

    But I thought the synchronicity of happening to be on the very page in "Crystal Sets to Sideband" that discusses one of your topics in the podcast!

  6. Hi Bill and Pete thanks for the podcasts, I was interested in Pete's comments re component values for AF phasor network. My comment is if the audio bandwidth of the transceiver were very limited, ie such as digital modes like PSK31, would the phasing network not be a lot simpler. If this is the case why has no one designed a simple phasing rig for digital only modes. I've seen some pretty complex designs for PSK31 transmission. 73 Rick G6AKG.


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