Herring Aid Error: C14

Yea, take a look at C14 in the AF amp.   At 1000 Hz 10uF is about 16 ohms.  That would put a serious dent in the AF gain.  And indeed, when I went back to my Herring Aid 5 (38 years from start to finish) and pulled C14 out, there was a dramatic increase in AF gain.  

Mistakes happen, but I wonder if anyone else spotted and reported this one.   Could someone with access to the QST archives check to see if an Erratum was ever published?   The project also appears in the 1977 ARRL book "Understanding Amateur Radio" with the problematic C14.  My guess is that it was just an error in the value of the cap.  

Can You See an Error in the Herring Aid Five Schematics?

Something caught my eye this morning.  Please take a look at the audio amplifier stages (Q3 and Q4) on the Herring Aid Five.  Can you see an error? Above is the original schematic from the 1976 QST.  Below is a 1998 update by VK1GB and KI6DS.  I see the same problem in both schematics.  Please let me know if you see an error. 

Six Stations Worked on BITX Night

I had a a good session with the BITX gang on 7277 kHz starting at  7pm local last night.  Keith N6ORS was on with his MIN-X rig (picture above).  Michael  KN4EAR's signal is much improved (Michael had worked Barcelona with his BITX40 Module earlier in the day). Randy WB5YYM's rig (featured last week on this blog) was booming in from Arkanas.  

LOG: WI1B Ken on BITX, AA4PG Pat, KN4EAR Mike in Falls Church, N6ORS Keith on MIN-X, W1LY Willy,  WB5YYM Randy in Arkansas

Hallicrafters and the Romantic Life of Private Hogarth

The world of the SolderSmoke podcast and blog are -- and will remain -- G rated.   But occassionally our discussion of ham radio technology causes us to bump up against some racy topics.  This happens VERY rarely, and that rarity probably says something about ham radio.   We have noted the alleged attractive power of Pete Juliano's French beret.  There was that April 1 story about the new SolderSmoke cologne ("chicks dig it!").  Jean Shepherd was a man of the world -- our discussions of him sometimes bring us a bit closer to the prurient boundary line.  We occassionally mention the lifestyle of the Dos Equis man.  But mostly, we stick to the circuitry.  

This morning I came across a character that I hadn't been aware of: Private (later Corporal) Hogarth.  He was the theme of a series of ads run by the Hallicrafters Company during World War II.  They were trying to sell their EC-1 broadcast receiver (essentially an All American Five).  Their advertising theme was, essentially, "chicks dig it."      

More of this here: http://www.geojohn.org/Radios/MyRadios/EC1/EC1.html

Don't blame me.  I blame Hallicrafters. 

The Road to QRO Perdition

I want to start out by saying that this is NOT my fault.  I have been TRYING to do QRP things. Remember my recent Tuna Tin 2, Herring Aid 5 rig?    I am aware of the ever-present threat of expulsion from the QRP HoF.   We all remember what happened to poor Pete back on April 1, 2017. 

But sometimes people just deliberately put temptation in your path.   That is what happened this week.  Our old friend Rogier KJ6ETL (formerly known as PA1ZZ) sent me the very LARGE chunk of aluminum that you see in the picture above.  Look at that thing.  It is practically begging to be turned into a very QRO push-pull amplifier.  

At first I told myself that it would be impossible to tap the big heat sinks on the sides.  How would I get the drill in there?  But then I realized that I can just put the threads in from the outside.  I can almost smell the machine oil. And the heat sink compound... 

Thanks lot Rogier. This is all your fault. 

  

More Stations Worked on Sunday Night with the BITXes

I worked AD0RW, AC9PD,  VE3ZBM and WB5YYM on 7277 kHz around 2345 Z Sunday 10 Sept 2017. BITX ops gather on that frequency on Sunday nights at around 7 pm local time. 

The station above is the impressive all HB 40 meter station of WB5YYM.  That's a 49er on the left, and a BITX40 on the right.  The amp in the middle has 2 IRF510s.   HB mic too.   FB

Amazing $49 Rig from QRP Labs

Hans Summers' QRP Labs has an amazing new rig -- The QCX --  that is chock-full of features and FB technology. Hans has long been one of the most innovative guys in ham radio, and this latest rig is one of his most amazing creations.  Like Farhan's BITX40 Module, this new rig is priced in the 50 dollar range. Hams who are paying many thousands of dollars for their "radios" should be asking themselves a question:  Could I be having much more fun for far less money?  This rig is in big demand and there is already a waiting list, so place your order now if you want to work on this during the winter.  Here is the link: 
http://qrp-labs.com/qcx.html

  

QCX Features:

• Easy to build, single-board design, 10 x 8cm, all controls are board-mounted
• Professional quality double-sided, through-hole plated, silk-screen printed PCB
• Choice of single band, 80, 60, 40, 30, 20 or 17m
• Approximately 3-5W CW output (depending on supply voltage)
• 7-16V recommended supply voltage
• Class E power amplifier, transistors run cool… even with no heatsinks
• 7-element Low Pass Filter ensures regulatory compliance
• CW envelope shaping to remove key clicks
• High performance receiver with at least 50dB of unwanted sideband cancellation
• 200Hz CW filter with no ringing
• Si5351A Synthesized VFO with rotary encoder tuning
• 16 x 2 blue backlight LCD screen
• Iambic keyer or straight key option included in the firmware
• Simple Digital Signal Processing assisted CW decoder, displayed real-time on-screen
• On-screen S-meter
• Full or semi QSK operation using fast solid-state transmit/receive switching
• Frequency presets, VFO A/B Split operation, RIT, configurable CW Offset
• Configurable sidetone frequency and volume
• Connectors: Power, 3.5mm keyer jack, 3.5mm stereo earphone jack, BNC RF output
• Onboard microswitch can be used as a simple straight Morse key
• Built-in test signal generator and alignment tools to complete simple set-up adjustments
• Built-in test equipment: voltmeter, RF power meter, frequency counter, signal generator
• Beacon mode, supporting automatic CW or WSPR operation
• GPS interface for reference frequency calibration and time-keeping (for WSPR beacon)

Today: 40th Anniversary of the Launch of Voyager 1

https://voyager.jpl.nasa.gov/          (Thanks Joh!) 

https://www.nytimes.com/2017/09/05/opinion/pondering-voyagers-interstellar-journeys-and-our-own.html?emc=edit_th_20170905&nl=todaysheadlines&nlid=54115026

Nuclear Powered QRPp? Tritium Nuclear Batteries and Plutonium Pacemakers

OK QRPers, it is time to explore another power source.  Enough of the nails in lemons and all that mess.  It is time to go NUCLEAR! Check out the motor in the video above, then look at the video below for more info on how the nuclear battery was made.  Who will be the first to QSO with homebrew nuclear power?  Or has it happened already? 

Mike Rainey -- this seems like the perfect project for you OM.


Oh and by the way, in the course of reading up on this, I learned that we once used PLUTONIUM to power pacemakers.  Check it out:

https://www.mdtmag.com/blog/2016/01/medtech-memoirs-plutonium-powered-pacemaker

And no, today is not April 1. 

SolderSmoke Podcast 199 Eclipse, Regen, BITX, DC RX, 3D OLEDS, Iphone Boxes, Mailbag

SolderSmoke Podcast #199 is available. 

http://soldersmoke.com/soldersmoke199.mp3

2 September 2017

The Eclipse.  The Floods. 

Sawdust Regen gets John Henry off to a good start. 
Voltage regulators as audio amplifiers

The return of the Simple-ceiver (Direct Conversion)

Ceramic Resonators

3D OLEDS

iPhone Boxes as rig enclosures

Electric Radio on Frank Jones

17 Meter Contacts 

MAILBAG

VE1LEB's Ergonomic BITX Enclosure (in Juliano Blue)

Wow, Michael's amazingly cool BITX enclosure looks like you could use it to ask Scottie to beam you up. 
Put an end to those freakish contortions -- 3D print yourself an Ergonomic BITX box! Very FB Michael. Thanks. 

Hi Bill and Pete:

I thought you’d be interested to see my ergonomic enclosure for the BITX40. While operating homebrewed regen radios, I noticed that my hands/arms/shoulders were becoming uncomfortable after a while. After thinking about this for a few days, I realized that the dials on the front of these small radios were forcing my hands into freakish contortions—and having both hands on the dials at all times while tuning made matters worster faster! So I did some homework and determined that our arms and hands most naturally hold things toward each other, as though they are holding a small cylinder by the ends. But the conventional “dials-and-speaker-facing-front” radio case forces us to twist our hands up and outwards from our bodies to twist things. See my blog post http://blog.generaleccentric.net/?p=2009 for illustrations of this problem.

My enclosure design for the BITX40 re-orients the volume and tuning knobs toward the sides of the radio, making their operation much more natural—and pleasant. Although it’s not retro, it does have an unconventional appearance and should fit in quite naturally with all the other homebrewed solutions featured on SolderSmoke. 

You can visit my post at http://blog.generaleccentric.net/?p=2082; the box is available for download and printing at Thingiverse: https://www.thingiverse.com/thing:2508147

By the way, I also have a 3D printable mic for the BITX40: https://www.thingiverse.com/thing:2500483

73, Michael VE1LEB

Something else "Completely Different": Meteor Pings

Very cool.  I want to try this.  I have the RTL-SDR and the software, so all I need is the antenna.  I may try to resurrect the 5 element 2 Meter Quad from my 90's adventures in the Dominican Republic (I still have the copper tube elements!).  I know the Graves radar is out of range, but there must be a suitable North American signal for this kind of thing.  Any ideas? 

For more info:
http://hackaday.com/2017/08/27/sorry-us-europeans-listen-to-space-with-graves/#more-270298

https://dk8ok.org/2017/08/23/graves-reflections-out-of-the-blue/