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Saturday, April 22, 2017

VFO Tribal Design Wisdom from Joseph Carr K4IPV (SK)

I had in my files somewhere this great article by Joseph Carr K4IPV about the design of ham band VFOs, but then I lost it.  Yesterday I found it, but the paper copy was in bad shape.  Internet to the rescue!  Here it is.  Go to page 79.

There is a follow-up article the following month, on page 78:

Something I heard on 75 meter AM this morning may have gotten me thinking about VFOs: I hear that International Crystals is going out of business.  That might be the last manufacturer willing to make bespoke crystals.   If that is true, that has big implications for homebrewers.   We will now have to build stable VFOs or succumb to the siren song of the digi synthesizers.  "L and C FOREVER!"

Joe Carr K4IPV mad so many contributions to the radio art.   I have several of his books.  He had a real talent for explaining circuits.  Sadly, I find very little information about him on the internet.  I know he lived in the same Virginia town that I live in.  Does anyone know anything else about Joe Carr? 

Wednesday, April 19, 2017


This was very cool.  I got on 40 SSB this afternoon with my trusty Digi-Tia.  I heard a station saying he was running 5 watts... Hmm, could that be a BITX40?  Indeed it was.  And it was the Peppermint Bark BITX 40 of Bruce KC1FSZ that we featured a few weeks ago.   He was up in Boston.  K3MY was kind enough to let us have the frequency.  Bruce and I had a nice contact.  He told me he is working on a completely scratch-built BITX.  FB.  TRGHS.   

Tuesday, April 18, 2017

Pete Juliano's Expulsion from the QRP Hall of Fame

First, I'd like to thank the many, many radio amateurs who sent in e-mails demanding that our friend Pete Juliano stay in the QRP Hall of Fame.  Their outrage at his expulsion was palpable.  They were angry and fired up.  Many compared Pete Juliano to baseball great  Pete Rose (who also got expelled from a Hall of Fame).   They wrote to us from all around the globe.  Several saw the action against Pete as yet another example of the deep divisions that are affecting modern society -- several saw it as being connected to our recent Presidential election, and/or BREXIT. 

Some writers took a diplomatic approach and tried to suggest ways that this ugly conflict might be ended -- one fellow suggested that Pete try to redeem himself by agreeing to enter some kind of QRP 12 Step Program.  Others got legalistically combative and said we should just "lawyer-up."

A number of our correspondents took note of the seasonal nature of these kinds of events. Who can forget the April  move a few years back by the New Jersey State Legislature to ban the use of soldering irons in the home?   "This kind of thing always seems to happen in the Spring-time!" said one irate Juliano surrogate,  "It is like Shakespeare wrote:  'Beware the Ides of March' -- only two weeks later!" Another ham also spotted the seasonal nature of these stories and quoted from T.S. Elliott's poem "The Wasteland":  "April is the cruelest month, especially the first day!"

We must point out that not all those who wrote were opposed to Pete's expulsion -- one writer said, "It is about time that that Pete "KW" Juliano got what he deserved! Good riddance!" (We have sent this e-mail to one of Pete's Italian-American relatives in New Jersey for, uh, action.)

Several of those who wrote in support of Pete are prominent members of the amateur radio community (they will -- if they follow our instructions -- remain anonymous.)

One activist supporter said that Pete's expulsion should lead to a street protest movement called "Pete's Award Matters" and that the chant at demonstrations could be "NO JULIANO, NO PEACE!"  Kind of catchy don't you think?

Anyway, we sincerely hope you have ALL figured out what was going on here. For those who have not, and for all those who wrote in, let me complete the tradition by saying it: "April Fool!"   

We'd like to thank all who participated in this long-standing amateur radio tradition.  Special thanks to Preston Douglas and the QRP-ARCI for putting up with all this.  (Tony Fishpool told us that he knew this couldn't be real, because someone as nice as Preston Douglas would NEVER expel anyone.)     

Sunday, April 16, 2017

Micro-Shocks (and QRP Power?) from Nearby High Voltage Lines (video)

I spotted this on Hack-A-Day.  It caught my attention because many time, while riding my bike along the Washington and Old Dominion bike path, I have felt electrical shocks from the handlebars. 
Now, before you all conclude that OM Bill is losing it and start suggesting that I wear an aluminum foil hat, realize that the bike path is directly under some seriously high voltage power lines.  And that esteemed UK newspaper "The Daily Mail"  confirms that these shocks are, as the kids say, a thing.
So think these Russian dudes are onto something.  How long will it be before the QRP community starts exploiting this power source?   (Please be careful about where you put the antenna!)

Saturday, April 15, 2017

Another Thermatron Receiver (video)

Thanks to Steve N8NM for sending this along.   He said it seems to be crying out for a synthesized VFO -- I disagree,of course. 

I like the filter arrangement -- one crystal at 455 kHz,  two tune-able IF cans and a phasing control.  This seems like a good way to get both AM selectivity (broad) while still having the ability to narrow the bandpass for SSB. 

The builder did a great job. Does anyone know who he is? 

Thursday, April 13, 2017

The Soul of the Old Machine

I continue to peruse the stack of Electric Radio magazines that Armand WA1UQO gave me last month.   Great stuff.  I'm really struck by how much of our ham radio history is captured in the pages of ER... and nowhere else.  This is a resource that should be protected.

In the last podcast I shared a few lines from the "Amateur Radio SSB -- The First Fifty Years" series or articles.  Today at lunch time I was reading the March 1994 issue, there was an article by Don Meadows N6DM entitled "A Homebrew CW Receiver."  From the last paragraph:

"This homebrew receiver as the main station receiver until 1975... In 1989 the homebrew receiver was finally mothballed... In its place I acquired an imported box that does everything.  This box is friendly and cooperative, but I have no rapport with its soul. When it ultimately falters, it will need to be cured in the manufacturers sanitarium for sick gear instead of on my own workbench.

I've always been proud of this homebrew receiver. It did its job exceedingly well. Retrieving recently this old friend from storage for photographs, cleaning out the dust and dead insects, inspecting its wiring up close --  all this evoked fond memories."

Tuesday, April 11, 2017

Stepping Inside an AM Transmitter (video)

Very cool video.  We have visited VE7ZWZ's amazing shack before. This time he takes us inside a BIG commercial AM transmitter that he has modified for use on the amateur bands.

I know that he had the plate voltage turned off, but I still felt myself cringing when he reached up to touch the plate connectors on those enormous thermatrons.  The filaments were on, adding to my unease.  Dude, don't do that! And if you are standing INSIDE the transmitter, keeping one hand behind your back might not be as beneficial as it normally would be.

His comments on his VFO were interesting.  I was kind of disappointed that he went with a varactor circuit.  A varactor?   Amidst all those bread slicer variable caps?  It just doesn't seem right.  (And BTW they are bread slicers, NOT "potato slicers.")  But I kind of liked the heater--thermistor--insulation set up that keeps the VFO at constant temperature.

I thought it was interesting that these transmitters were kept on, with the tubes glowing for years at a time.

Thanks Mr. Carlson, for another great video! 

Monday, April 10, 2017

Very Useful Toroid Info Web Site

This site provides the kind of info we need when working with toroids.  It even tells you the length of wire to cut. It links to the W8DIZ "Toroid King" website, but I can't really tell if this site is the work of DIZ himself.   In any case, very useful.  We award this site our coveted rating of "Five Soldering Irons."

Sunday, April 9, 2017

Video of a REAL Homebrew QRP Contact (by WU2D)

I think Mike's video does a good job of showing what it is really like to get on the air with simple, homebrew QRP gear.   It takes some patience and operating skill.  I guess it is sort of like fly fishing (with home made lures); there are easier ways to catch fish, but they are not as rewarding.   

Saturday, April 8, 2017

Discrete Dead-Bug O'scope Pong

Thanks to Bent KD0GLS for alerting us to this excellent example of the awesome power of discrete transistors and dead--bug construction.
Check it out.  There is a video.

Thursday, April 6, 2017

Hot Water BITX 40

Fred's idea really resonated with me.   My first SSB rig was an HW-32A, the 20 meter version of the rig shown above.  If -- as I suspect -- these rigs are anything like the HW-101, they are not aging well. Heath's drive for economy resulted in rigs that don't hold up to well over time. I remember the sound of the  plastic HW-101 dial clutch cracking when I pushed the button.

BITX40 Modules to the rescue! Put a mono-band board inside an old mono-band rig.   There are a lot of possibility here.  Some ideas:

-- Put that Heath VFO to use.  Maybe convert it to solid state.  Or just put the LCD from an Si5351 in the window (Pete did this with an HW-101).

-- Get the S-Meter wiggling.  

-- Keep the final amplifier circuitry in there and let the BITX drive it.  This will give you a QRO option.  (Uh oh, we're in trouble again!)   

Hello Fellows,
Attached is a picture of my BITX-40 V3 adapted to a Heath kit Single Bander HW22. This is a work in progress but what a neat way to bring an old boat anchor into the present.
The only parts of the HW 22 used were the front panel and case and knobs. Modifications yet to be  incorporated include: AGC , a USB port on the front panel to access the Arduino, and a PTT/CW mode switch.
I enjoy your pod cast and web site…Best of 73 KC5RT.

Wednesday, April 5, 2017

Hearing the Roosters from Boa Vista, Brazil

The ham radio day got off to a good start at N2CQR yesterday.  40 meters was open in the morning and PV8AL was calling CQ.  Helio had a strong signal, due in large part to his 3 element 40 meter yagi.   Helio lives on a farm outside Boa Vista,  Brazil. As he spoke, I could clearly hear the roosters crowing in the Amazonian dawn.  Very cool.  It brought me back to mornings in the Dominican Republic, and in Central America. It also reminded me of one of my first DSB contacts from the Azores -- I could hear the parakeets of Amadeu CT2HGL in Coimbra, Continental Portugal.  Obrigado Helio!  Obrigado Amadeu!

Tuesday, April 4, 2017

Fast Radio Bursts and the Molonglo Radio Telescope (with video)

7,744 circular dipoles on 843 MHz  feeding 176 preamplifiers and 88 IF amplifiers!

Read about how the Molonglo Radio Telescope has recently been used to study the mysterious Fast Radio Bursts:

There is a Grote Reber connection:

Saturday, April 1, 2017

SolderSmoke Podcast #195: (We need some help!) BITX, 60, SSB History, Tribal Socketry


SolderSmoke Podcast #195 is available.  Link appears below (scroll down)

We’ve got a problem:   Pete Juliano and the QRP Hall of Fame  :-(  PLEASE HELP!

Pete Releases Smoke (wiring harness)
Pete's DifX on 60
Architecture and Dual Conversion (uBITX:   uses ALL THREE clocks on the Si5351)
The Big Kahuna
ON HACKADAY with Philco SB100 SEE!  QRP!!!!!

Cap Stack Hack mod (with leads)
Let the smoke out of an Si5351 (shorted output) Several actually.
(Same day delivery zone for Amazon -- but no drones or parachutes yet.)
Installed scanning switch
Observations on 60.  All the weird bands have a 6 in them: 160, 60, 6
The good:  100 watt limit, wire antennas 
The bad:  Kind of cliquish-- like 75, not much of a CQ band.  Channels.  Not much activity.
Met Josh KE8CPD on 40.  BITX 40!

Socketry:  How to keep BNC jacks from spinning loose?
Do you heat shrink?

Feel Tech Sig Gen might not have blocking cap at the output.
Speaking of which, when I spoke of the Ne602, I mostly meant blocking caps, not bypass caps.

How come they don't have a cable TV channel devoted to radios?  They have HGTV? Why not HBTV?

Bad weather.  Tailgaters wimped out!
Combined forces with Armand WA1UQO.
Met up with Charles AI4OT.
Acquisitions:  1/4 phono jacks, carbon mic, vero board, disc caps, weather radio,
LARGE collection of Electric Radios from Armand.  Wow.

Electric Radio notes:   1st Fifty Years of Sideband 1991 articles by Jim Musgrove K5BZH
Why LSB on 75? -- so AMers couldn't follow to top of band
W2, W6, W8s liked phasing, W3, W4, W0 more into filter rigs.
Early SSB guys turning on carrier and talking AM hams into SSB RX.
Kelvinator Refrigerator rigs.
A reading on the homebrewing of SSB rigs.

Tony Fishpool on QSO Today!  Pete mentioned prominently.
Good Hacks from ND6T on BITXHacks,   Stockton Bridge


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