Back to the Barebones (Receiver)

My rehabilitation of homebrew 17 meter gear from the last solar cycle continues. Following the same path that I followed in 2001-2002, I will now move from DSB to SSB. I pulled out the little receiver that I put together way back when. It is a version of Doug DeMaw's "Barebones Superhet" (aka "Barbados Superhet"). I bought it on the net. It had been put together by a skilled builder on a FAR Circuits board. The fellow who built it had changed the IF from Doug's original color burst freq (3.579 MHz) to 5 MHz. He had also put in a varactor controlled VFO using a DC voltage multiplier to get more voltage variation across the varactor. I also think he had it built for 20 meters.

I converted it to a 17 meter receiver. I put in a VXO, using two crystals controlled by a panel switch. I also changed the caps in the filter so as to broaden the response for SSB.

As I was going through all these modifications, I turned to the USENET for help and advice. Dale, W4OP, came to my assistance. Little did we know how DETAILED his familiarity with my RX was:

"Bill N2CQR MOHBR" ...@virgin.net> wrote in message

news:22f6e3ee.0503292244.1b9a1481@posting.google.com...

> Dale: Wow, another Barbados RX builder. That was my first successful
> superhet project. I now have the one I built (still on 20), and this
> morning
> I got another one (the one built by someone else on a factory-made
> board)going on 17 with a VXO. I have a THIRD partially built Barbados
> RX board. If this
> keeps up, I'll soon have a BBRX museum.
>Hi Bill,

Did I sell you mine years ago? I seem to recall using a temp stabilized
varicap in a shielded enclosure for main tuning. It was done on a factory
board. Or was that a 6M xverter I sold?

Dale

Newsgroups: rec.radio.amateur.homebrew From: meara.lon...@virgin.net (Bill N2CQR MOHBR) Date: 30 Mar 2005 22:33:57 -0800 Local: Thurs, Mar 31 2005 1:33 am Subject: Re: Homebrew projects Dale: Wow, small world! Yea I think that is the one I'm working on. I think you also had a DC-DC converter to bring the voltage to the varicaps up. Very nice enclosure for the oscillator. I now have it percolating nicely as a VXO around 23 Mhz (for the 17 meter band). Bill - Hide quoted text -

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Arduino and the Techno-Hippies

Phillip Torrone over on Maker blog has a good article about the Arduino, and what you can do with it. I especially liked his comments on the "techno-hippie" aspect of the Arduino project (“Arduino: baby-talk programming for the pothead”), and how it might be "Italy's Google."

Check it out:
http://blog.makezine.com/archive/2011/02/why-the-arduino-won-and-why-its-here-to-stay.html

Will we soon see Arduino's working alongside Raspberry Pi computers?

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Homebrew Hero: Kazuhiro Sunamura, JF1OZL

In case anyone in the SolderSmoke community has not yet visited the site of Kazuhiro Sunamura... Be sure to check out his site. He has a really amazing range of projects:

http://www.intio.or.jp/jf10zl/

Here is the bio of OM OZL. As you can see, he definitely has the Knack, and clearly has the sharing attitude of a true member of the International Brotherhood of Electronic Wizards:

My name is Kazuhiro Sunamura. I am a 50 year old mechanical engineer, born in 1956. I am not an engineer in electronics. I have been interested in electricity and radio from the age of ten. For the last ten years, I have been active on my ham radio station JF10ZL. I have also written articles about my some of my radio projects in Japanese for the Japanese CQ Magazine. Now I have decided to get onto the internet and will take the opportunity of showing you my equipment and ideas. Please have a look at my schematics. I will be very happy if this material helps you with your own radio projects. I am a member of the J.A.R.L. affiliated Tsuchiura Club, the local ham club in my home town.

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DSB QRP DX on 17

The solar flux index is now above 131 and the effects are very apparent on 17 meters. (I will pull out the telescope this morning to get some direct confirmation of improved solar conditions!) This morning I worked Daniel, F5BBD, with my little DSB rig with the 5 watt JBOT amplifier. Very solid contact. He gave me a 55. I hear Japanese stations in the evening. And I am hearing guys on 17 who I haven't heard since the last solar cycle: My friend Chris SM0OWX seems to be right where he was when we last spoke.

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Find your Estes Rocket Catalog Online

On Wednesday we were all waxing nostalgic about 73 Magazine. (Did anyone figure out how to download ALL 511 of them?) I mentioned that I read many of the early 1970s editions from cover to cover. This morning I found on the Maker blog links to another publication that was burned permanently into my adolescent memory banks: The Estes Model Rocket catalog. Wow, I spent a lot of time studying the tech stats on the various rockets and rocket engines. (A8-3s!) I suspect that many SolderSmoke fans were also Estes enthusiasts.

Here are ALL the catalogs:
http://www.estesrockets.com/customer-service/full-catalog/

I think mine was the 1971 edition (above). I still feel bad about losing my Astron Big Bertha. And guilty about all the frogs I killed in the Astron X-Ray. I forgot all about the rocket with the 8 mm movie camera.

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73 Magazine -- Online!

Some of my earliest ham radio memories are of 73 Magazine. Perhaps this has something to do with the electro-erotica cover shots of the early 1970s! I used to buy copies at "Electronics 59" in Spring Valley, New York. I remember struggling to understand the magazine: Why were these guys so obsessed about going to Navassa Island? Why was there a column entitled "Never Say Die?" Why was the classified section entitled "Caveat Emptor?" In time, all this would become clear to me. Occasionally, I'll come across an old issue and will suddenly remember it from when it first came out. I must have read these things cover-to-cover. (Jean Shepherd recalled reading even the grommet ads in the old QSTs.)

I really liked 73. It always had a zany, edgy, kind of "out-there" feel to it. Of course, near the end it went too far off the reservation (Bio-electrifiers? Faked moon walks?)

This morning QRP-L brings us the news that all the back issues are available on-line:

http://www.archive.org/search.php?query=collection%3A73-magazine&sort=-publicdate

I'm hoping that somewhere in there we will be able to find that early 70's article about the varactor-tuned DC receiver that I tried to build but couldn't get working.

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A WWV Trick with the Drake 2-B

I was reading the October 1962 issue of 73 Magazine (we're always on the cutting edge here!). In the back pages a little piece from K4FQU (quite a call!) about the Drake 2-B caught my eye. OM FQU points out that by putting the bandswitch on 40 and the preselector at 10, WWV's 15 mc signal can be heard at the zero position on the 2B dial. It works! The familiar time signal beeps are coming through nicely here. It's fun to teach an old dog new tricks!

If you are looking for a 2-B, Bill KE5VZT alerted me to this one:
http://forums.qrz.com/showthread.php?325222-Drake-2B-with-Q-mult-amp-speaker

On the same page there is a review of a new Double Sideband rig from World Radio Labs -- the SB-175. Sounds like a winner!

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"The Little Sweetheart" Receiver

Wow, what a beautiful piece of work! And a fascinating story behind it, with hints of wartime romance... Thanks to Mike AA1TJ whose very eclectic reading (Czech tech mags!) led us to this. Thanks also the Crypto Museum. Here is the link:

http://www.cryptomuseum.com/spy/sweetheart/index.htm

With more info here:
http://antiqueradios.com/forums/viewtopic.php?t=96007
And here:
http://antiqueradios.com/forums/viewtopic.php?t=96057

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Amateur Radio Balloon Crosses The Pond (and the Continent)

Wow, congratulations to the California Near Space team. Their balloon flew from Silicon Valley, across the U.S., across the Atlantic and is now en route to Italy. As a former Azores APRS operator, I was pleased to see the APRS report from those islands. George, KJ6VU, of Sierra Radio Systems, was present for the launch.

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Have An Oz Knack Christmas with VK2ZAY!

This is not the most flattering picture of our friend Alan, VK2ZAY, but I find myself forced to use it (again!) because of the Christmas light head-gear. Sorry OM.

I was thinking about Alan just the other day as I contemplated my broken Lafayette power supply (scroll down to the test gear article). You see, the meter in that little supply was destroyed by a trivial electric motor that Billy and I built a long time ago after a visit to Alan's amazing site. Don't worry Alan -- the broken meter is not your fault.

Once again proving that he is a true Knack victim and a certified member of the International Brotherhood of Electronic Wizards, Alan is doing an "Advent Calendar" of YouTube tech videos -- one short video each day during the Christmas season. I looked at a couple of them this morning. You guys will love them. Alan obviously has a deep understanding of the circuitry and a great talent for explaining how his creations work.
Thanks a lot Alan! Here is the link:

http://www.youtube.com/user/vk2zay

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Seeing EM Waves with a Coffee Can

Thanks to Leif KC8RWR for alerting me to this. Amazing stuff, but somehow I think they need to get an Altoid tin into this project. You can sense the enthusiasm.

"Particles? We don't need no stinkin' particles!"

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The "Snort Rosin" Test Gear Philosophy

Steve Smith, WB6TNL, and I often find ourselves on the same frequency:

Hi Bill,

After reading your latest blog post, I realized that you and I are somewhat kindred spirits. You successfully build and test relatively complex amateur radio equipment using the most basic and inexpensive test equipment.

As part of my business (land mobile radio) I own expensive and complex test equipment, however when I build and test homebrewed amateur radio gear I prefer to use inexpensive home-built or kit-built test equipment because that is what is generally available to most hams. My philosophy is that it is very important to impress upon beginning homebrewers the fact that fancy, complex test gear is not absolutely necessary to be successful in homebrewing.

Perfectly functional test gear can be built using only basic electronic tools. Certainly, homebrewed equipment might not have all the 'bells and whistles' of commercial gear and won't do everything 'automagically' but with careful calibration and learning how interpret the results, homebrewed test equipment can provide very accurate measurements.

One good example is your Palomar R-X Noise Bridge. Most every ham wants a MFJ 259B or Autek VA-1 antenna analyser but an inexpensive bridge like the Palomar or a homebrewed equivalent can provide many of the same measurements. Sure, a ham-band or general-coverage receiver is required to use a noise bridge but, by using -very- simple circuits, a very competent test receiver can be built using the most basic test gear. Even with only a good SWR meter and a little math thrown in, +/- Xj (reactance) measurements can be made (See http://www.qsl.net/n8xpv/ for information regarding "the 3 meter method" ).

One of my favorite resources for simple test equipment is Monty Northrup's (N5ESE} site: 73.......

Steve Smith WB6TNL "Snort Rosin"

From:

"solder smoke"

To:

"Steve Smith"

Great message Steve. Yea, I think the best troubleshooting tool is a real understanding of what is happening (or supposed to be happening) in the circuit and an ability to think logically about what could be causing the problem. Technical detective work. And indeed, that SWR bridge can tell you a lot.
73 Bill

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Test Gear/Workbench Maintenance

I mentioned in the last podcast that I was going to take a break from construction projects and spend a little time fixing up tools, test gear, and the work bench. First up was my old soldering gun. I bought this thing almost 40 years ago! It is pretty beat up, but I managed to patch it up and it now works fine. Even the original light bulb works.

I use this little AADE L/C meter a lot, but was having trouble getting parts across the test terminals. So I soldered alligator clips onto one of the parts connectors that came with the device. Makes testing easier.

Just a little audio oscillator. Puts out .2 volts at 713 Hz. Useful for testing the phone rigs.

I picked up this little Lafayette power supply at a hamfest and found it quite useful. But then I managed to knock the needle off the meter while fooling around with trivial electric motor. Any ideas on where I could get a replacement meter movement, or on what value I should use?

Here is a wave meter that I picked up at the Kemptom Park rally in London. Apparently at one point all UK radio amateurs were required to have one of these devices. I'm tempted to chop it up for parts. That variable cap with the reduction drive looks promising. And could that meter solve my problem with the power supply (above). If anyone can think of a reason to keep this as a wavemeter, please let me know.

Further proof of my extreme retro-ness. This is what I use as a signal generator. A Heathkit SG-6. Older than me!

This is my scope. HAMEG. Supposed to be good to 10 MHz but of course I can use it at higher freqs (which I do). I need to upgrade. Any suggestions?

A very useful little square wave generator.

I need to make more use of this noise bridge. Lots of potential here.

Obviously a London purchase. Very useful little AF sig generator from the UK's equivalent of Radio Shack. My only complaint: No auto-off. I forget to turn it off and run down the two 9 V batteries.

Long time listeners will remember this device. This is the one in which I soldered in the chip upside down. It works fine on th 5 Hz to 100 MHz range. Dead on the 4 - 600 MHz position.

I bought this power supply at the Kempton Rally, then converted it into a current limited supply using a chip and a circuit provided by Tony, G4WIF. My daughter Maria helped paint the cabinet. Lots of soul in this little machine.

Just three meters. The middle (analog one) is still very useful, and has considerable sentimental value for me -- my wife got if for me when we were back in the Dominican Republic.
My version of the W7ZOI power meter. Mike, KL7R, and I built versions of this device back in 2004 or so.
This is Cappuccio. He joins me in the shack most mornings. I'm not really a dog person, but I'm growing fond of him, even though he occasionally eats resistors and capacitors.

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Homebrew Ferrari

Speaking of homebrew motors, a number of people sent me this YouTube video about another intrepid European with amazing workshop skills. Great stuff. (It reminded me of the title of one of Jean Shepherd's books: "Ferrari in the Bedroom.")

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The Woz's Early Exposure to Electronics

Here is what I was trying to --- hic-- say about Steve Wozniak --hic-- in Podcast #139:

From "Steve Jobs" by Walter Isaacson:

"One of Steve Wozniak's first memories was going to his father's workplace on a weekend and being shown electronic parts, with his dad "putting them on a table with me so that I could play with them." He watched with fascination as his father tried to get a waveform line on a video screen to stay flat so that so that he could show that one of his circuit designs was working properly. "I could see that whatever my dad was doing, it was important and good." Woz, as he was known even then, would ask about the resistors and transistors lying around the house, and his father would pull out a blackboard to explain what they did. "He would explain what a resistor was doing all the way back to atoms and electrons. He explained how resistors worked when I was in the second grade, not by equations, but by having me picture it."

This is clearly the approach to electronics that we see in the book "From Atoms to Amperes" by F.A. Wilson.

Mike, KC7IT, gave Woz a new title "the uber-knack-master of all time":

Woz is the uber-knack-master of all time, and always has been in my book. His Apple II design is a work of genius in getting ten pounds of function out of five pounds of parts.

One of many examples: Apple II was the first personal computer to use DRAM memory chips, which were brand new then and kinda scary even for us pros. DRAMs store data as charges on tiny leaky capacitors. Every 20 milliseconds or so they have to be refreshed.

Everyone else had counters and logic just for refresh. Woz arranged the Apple II's display memory, so reading out the pixels to the TV screen 60 times per second did the refresh too, at no cost in circuits or performance. The elegant design of a pure knack genius.

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Hiccups in SolderSmoke 139

First there was the whistling of my SSS sounds (a speech defect that I had been blissfully unaware of due to a nullifying case of tinnitus!) Then, in SolderSmoke 139 the long-suffering SolderSmoke listeners had to put up with hiccups. Yea, around 53 minutes into the show there began an annoying series of hiccups. Being an essentially analog kind of guy, I'm sort of pleased to point out that these are DIGITAL hiccups, apparently introduced by the Audacity software during the actual recording (not when I converted the show to mp3). I've been having more than my normal share of road-kill computer problems lately. The laptop I'm using to record the show ate a couple of the recent episodes before I had a chance to upload them (I had to do them over -- that's very frustrating). So this time I was recording the show on a thumb drive. Apparently it was filling up as we got close to the end, which led to the hiccups. The worst part was that a hiccup came just as I was delivering a key quote from The Woz. (I'll post it.)

If anyone has any gear laying around that might with these problems, please send it my way. Obviously I could use a bigger thumb drive. An external sound card might be nice. I could probably use another laptop also...

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30% off on SolderSmoke, The Book. December 7

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http://soldersmoke.com/book.htm

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Messaging ET (METI), and Silicon-based Life Forms

My fellow beacon fans will like this one. The ultimate (REALLY ultimate) beacon! http://www.newscientist.com/article/dn21236-lets-build-a-beacon-to-tell-aliens-who-we-were.html?page=1

And then there is this article about silicon-based life forms. (At first I thought they were talking about us!) http://www.universetoday.com/91449/why-silicon-based-aliens-would-rather-eat-our-cities-than-us-thoughts-on-non-carbon-astrobiology/

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SolderSmoke Podcast #139

December 3, 2011

http://soldersmoke.com/soldersmoke139.mp3

Halloween, Thanksgiving, and Billy's Birthday (on the range!)

Astro-Knack: CCD camera in the telescope. Solar astronomy.

Winter approaches: Shack heating by Heath, Halli, Hammarlund and Drake.

2B troubles on 17 meters.

Rig Re-Cycling: Rebuilding 17 meter rigs from the last solar cycle.

Azores DSB re-build: Oscillator troubles then adding a JBOT.

Manhattan style construction and the need for urban renewal.

Book Review: Steve Jobs. (Woz has the Knack!)

MAILBAG

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An Inspirational Homebrew Motor from Spain

Bruce, KK0S, alerted me to this inspirational masterpiece from Spain. It is, as he points out, one of a number of really great videos about top level homebrew craftsmanship from Europe (remember the French homebrew tubes?).

Other comments from Bruce:
Did you notice that the calipers and micrometer this guy was using were seriously old-school. Totally manual readout. Not even a dial on that set of calipers! On top of that, his little lathe was manually fed. Notice in one of the shots, he is shown turning the cross slide feed wheel. No CNC anywhere. I can't be positive, but I don't think the lathe had a digital position readout either. This man is a machinist in the truest sense of the word. The Knack not only lives - it thrives!

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Secret Listeners -- The Voluntary Interceptors

Jim, AL7RV, and several others sent me the link to this really interesting video about the British radio amateurs in WWII. Real "stiff upper lip" spirit in this video. Musn't grumble! Great stuff from Great Britain: http://www.eafa.org.uk/catalogue/5108

That regen receiver they showed looks a lot like the beast that I brought back from the UK with me. Once again, I am hearing the siren song of the diabolical regens....

Progress continues on my Indian-ized Azorean DSB transceiver (with JBOT amp). I now have the amp nicely stabilized (thank God!). Now I just need to get the output from the balanced mod close to the 1 mW PEP level needed by the amp. Should be done soon. And my cold seems to be going away, so maybe I'll be able to share my tales of JBOT derring-do in a podcast this weekend.

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