A BITX-20 Emerges from the SolderSmoke

It's  not mine -- I haven't started yet.  But Robert sent us this picture and progress report on his BITX-20  project. (Nice Tek scope in the background.  Is that a 465?)
---------------------------
Dear Mr. Meara,
    Thank you for sharing your thoughts and experiences in
SolderSmoke. I found your book (kindle version), to be entertaining and
inspirational. The amateur radio bug bit me hard early this year, earned
my tech & general in January, extra in February. Asking myself "Where
has this wonderful hobby been all my life"?
    Especially want you to know that because of the reference of the
Bitx20 in your book, I built one (kit from India), and made my very
first hf contact using a homebrew rig and homebrew dipole antenna. The
thrill was absolutely fantastic! Attached is a picture of my bitx20
moments after making my very first hf contact ever between northern
Alabama (my QTH), and the Calgary Alberta radio club about 2k miles
away.
Please take some credit for being part of the inspiration!
    Note, my bitx20 is now packaged and portable, next project will
is a QRP antenna tuner, and buying a commercial "fancy" HF transceiver.
Thanks again!
Sincerely,
Robert Conklin

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AA1TJ -- As always, in the Vanguard

Here is a recent e-mail exchange between Michael, AA1TJ, and Dale, W4OP.  (Dale happens to be the fellow who built the W1FB Barebones Superhet that I am currently using on 17 meters. Details on this caper appear in SolderSmoke -- The Book). 


----------------------------------------------------
From AA1TJ: 


Wahoo...Dale, you amazing!

You are my first QSO with the Vanguard 1 reproduction satellite beacon transmitter. My circuit is a fairly close copy of the one shown on the lower left-hand corner of the 1959 CQ Magazine article (notice the output signal pick-off shown in this schematic is incorrect, or at least incomplete). My circuit uses link-coupled output impedance matching, which is similar to the only other documentation that I was able to dig up. The attached image "Early_Microlock_Bcn.jpg" was snipped from an original NASA report on the transmitter used in early airborne and sub-orbital tests leading up to the Vanguard flights. 

Yes, you heard correctly. I'm using a Philco 2N504 surface-barrier transistor, but please let me back up a bit. 

Roger Easton (a native Vermonter...and still resides here!) was at the helm of the communications development for the Vanguard/Minitrack project. Of the Vanguard "grapefruit" satellite beacon transmitters, he wrote in the May 2008 issue of High Frontier magazine

"We tried subminiature tube transmitters first. They worked marginally. Finally, Bell Telephone/Western Electric developed a very nice transistor for the task, and the problem was solved." 

However, that leaves out a small detail. They first tried Philco surface-barrier transistors, which worked fine on the bench, however two problems were discovered. They were found to be too temperature sensitive; the RF output power from the one-stage transmitter dropped excessively at elevated temps. Secondly, there was some issue with the packaging that produced erratic operation when the transistor was rotated positionally. The Western Electric devices proved better on both counts. 

The WE transistor appears to be "unobtainium" these days. That, plus the fact that my circuit won't be flying up to space anytime soon, prompted me to settle on a Philco 2N504. Although my device was manufactured in September of 1959 (Vanguard TV-4 - re-Christened "Vanguard 1" - first orbited on March 17, 1958), the 2N504 was an off-the-shelf item on the launch-date.

The only other obvious difference is the Vanguard 1 beacon circuit operated on 108MHz, whereas mine is presently working on 14.0596MHz. I recently had it running as a beacon on 10m for 48 hours but I had no luck given present band conditions.

The receiver is a simple, 0-V-0 regenerative set using a single Raytheon QF721 (fabricated in February 1953). I heard little activity on 20m when I started up my auto-keyer this morning. I had it looping 3X1 CQs whilst I worked on another project. To make matters more difficult, the exhaust fan was running in my shop and it happened to be raining heavily when you called. Worse yet, the receiver had drifted off my calling frequency by the time you called. I barely discerned a high-pitched CW "1" or "J"...which prompted me to quickly switch off the fan and re-tune. You were subsequently a solid 579. 

Of course my heart jumped when I heard you calling me...how I love that feeling! And it was a fabulous QSO so far as I'm concerned. Following our contact I opened my metal index card file box and pulled out the QSL that you sent to me following our "Code Talker" QSO. To think I now have another happy memory to add to that one! Thank you once again, Dale. It figures you'd be the one to pick-off my unannounced presence on the 20m QRP calling frequency with 25mW. Well done, OM. 

Also, you might enjoy this video of the actual launch, including some interesting control room audio banter. It may be found here: http://www.nrl.navy.mil/vanguard50/index.php. The way at least one of them nervously repeats, "Keep going baby!" gives some indication of the pressure these guys were under...having failed so spectacularly on two previous occasions. 

All the best,
Mike, AA1TJ    
        

On Mon, Jun 25, 2012 at 11:51 AM, Dale Parfitt wrote:

Hi Michael,

That was fun!

I first heard you on my SG-2020 rig, but did not have a paddle handy, so I fired up the K3. I don't ever recall having QRN on 20M, but it was  bad. Without it, you were 579 and even with it, 569 towards the end of the QSO.

I just happened to be QRV on 060 listening when I heard your CQ's. Not bad for a 25mW signal from (I think you said) a Philco transistor.

73,

Dale W4OP

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Good Emergency Advice from Her Majesty's Government

I thought of this during our recent bout with the "Derecho" storm and the subsequent power outage. It is not really from HMG of course -- it is actually the work of Carl, 2E0TEC. But I'm sure HMG would be on-board with the "musn't grumble" "stiff upper lip" spirit of the poster. Now if I could only get my soldering iron to run off the solar-charged 12 volt gel cell....

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Hit By Storm

On Friday night the Washington DC area was hit hard by a very powerful line of thunderstorms.  It brought down trees and powerlines all around the area. Fortunately, my dipoles were spared.   But we were "off the grid" for about 48 hours.  Let me tell you, it is no fun at all.  I am now in the market for a generator and would appreciate recommendations (gasoline?  natural gas?)  I was re-introduced to the joys of 2 meter FM.   I thought my smart phone would keep us connected to the net, but AT&T apparently lost some of its towers in our area, so for a while, the only way we could have called for help would have been via 2 meter FM.

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Arduino's Massimo Banzi Talks Homebrew

I liked Banzi's presentation and I think you guys will like it too.  Arduino and the open source movement seems to have something in common with of the old ham radio tradition of helping fellow amateurs.  Bravo Massimo!

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Angelo's ATR-4

On Monday I was talking to Angelo, W8ERN, on 17 meters.   He told me about an SSB transceiver that he had designed for ELMAC, the ATR-4.   Take a look at that beauty.   The amazing thing is the year in which Angelo created this rig:  1959!  Wow, talk about being ahead of its time!  Sadly, ELMAC decided not to produce it, and only a few prototypes exist.  It is 80-10 meters, SSB and CW featuring a crystal filter. It is a transistor-tube hybrid with a pair of 6146's in the final.  Nice job Angelo.  

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HW-7 fixed after 36 years!

Give this man a license!  He deserves one.  Great job David. 
-----------------
Bill,

Found your podcasts (137 & 8) about the HW-7. Really enjoyed hearing your enthusiasm. I have owned one since 1976...my dad purchased it for me while at the Dayton Hamvention. Unfortunately it didn't work when we plugged it in. Dad didn't have the money to fix it at the time and as a 15 year old, neither did I. So it went into a box and was stored. 

Fast forward to 2008 and my youngest son asked me what Morse Code was. I told him and showed him...I didn't remember hardly any code. He wasn't interested in learning that didn't deter me and I wondered about the HW-7. So I went to the attic and found the box with the old rig. It still didn't make a sound when turned on so I decided to crack the case open and go through the troubleshooting guide...I had the manuals for both the radio and power supply. I determined the 40673 was bad. 

Got online and snooped around and couldn't find a source for a replacement so I started looking into equivalent parts and ran across the NTE454. Ordered it, made some "soldersmoke" and replaced it, turned on the radio and was happy to hear hum from the power supply in my headphones. Switched over to a 9 volt battery, attached a long wire and was blessed to hear CW coming through loud and clear! 

Dad, a ham from years past, almost didn't believe me when I called to let him know. "Fantastic!" was his response when I explained how it happened. (He's an EE and I'm a graphic designer.) 

During the investigation I also discovered that the original owner never finished the assembly guide. Found a tool at Radio Shack that I could tune the coils with, borrowed a frequency counter from a local TV station's tech and with dad's help aligned the rig according to the manual. Got the dial into rock solid sync with the FC. Both on RX and TX. 

I never heard what it sounded like with the 70673, however, looking at the data sheets for both Mosfets, the noise level of the NTE454 is lower. Typical for the NTE454 is 1.8 compared to 3.5 of the 40673. The max is 4.5 compared to 6.0 according to RCA. I have ears, thank you, and have copied a station located halfway down the Baja peninsula running 100 watts into a vertical. I was using a dipole 12' up in Indiana. I say copied because I have yet transmitted with it. Because of life I have been delayed (many years) in getting my ticket. However I will be taking the Tech exam...possibly even the General exam in July...but I have a bit more study to do for General. As a tech I would only be able to use 40 meters 

I have retrieved dad's J-38...still sporting the 76 Dayton Hamvention sticker on the bottom, polished it up and have been practicing for when I can get on the air. 7 1/2 WPM currently, but slowly gaining. I hear that working stations on the air will help the speed increase.

Anyway, the HW-7 is going to be my rig for a while...thought about selling it...because of the stories I've read...but I like listening to it JUST LIKE YOU for the SSB rag chews near the top of the 40 meter band. I also listen to the slower guys on CW to get my ear tuned to it. You also confirmed how to tune and listen so I will have possibly, an easier chance in making contacts. I also know a few local hams that can schedule with me. 

The HWA-7-1 power supply needs mods though. Plan on putting in place some caps and some magnetic beads to hopefully reduce the hum to a respectable level. Anyway, I appreciate your sharing and hope to work you sometime.

David Oldham

Greenwood, IN

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Poor Conditions: SFI 89. Venus Transit Hero

There's today's image from SOHO.  Pretty barren.  That's why conditions on the HF bands are so poor today.

While looking for this I came across this account of Venus Transit Heroism:

 In the days of heroic astronomy, Chappe d'Autoroches not only risked his life twice to obtain critical, new knowledge from transits of Venus, but gave his life to help others in dire need. Here is his tale from the h2g2 web site in an article entitled "Forgotten Male Astronomers:" A French expedition led by Jean-Baptiste Chappe d'Autoroche (1728 - 69) went to Tobolsk, Siberia, to record the 1761 Venus transit. The team survived a treacherous river crossing and a lengthy journey through difficult, boggy conditions, eventually arriving at their destination just six days before the transit was due. Just before the transit, Jean-Baptiste was attacked by some of the locals, who believed he had caused unusually severe spring floods by interfering with the Sun. Cossack guards managed to save the team of astronomers, who eventually managed to make good observations of the Venus transit.

The French Academy were so pleased with the success of his mission that they engaged Jean-Baptiste to record the next expected Venus transit, due in 1769. He specified that he would travel anywhere in the world as long as the temperature wouldn't be below freezing. Tragically, when Jean-Baptiste and his team arrived at Vera Cruz in Mexico, they found themselves in the middle of a plague [yellow fever] epidemic. Instead of moving on to a safer place, the team decided to remain and help care for the sick villagers.

Even though he was mortally ill, Jean-Baptiste managed to record astronomical observations to establish the latitude and longitude of the site. These recordings were vital for the calculations of the astronomers back home in France, and were made with an astonishing accuracy, given the hazardous conditions in which the data were gathered. The observations they made provided some of the best data of the 1769 transit. Jean-Baptiste died of a fever just after the transit, aged 41 years.

A longer and more detailed version of these events can be found here: www.americanscientist.org

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"The Journey to Palomar"

This is a wonderful documentary that will definitely appeal to SolderSmoke listeners.  Check out Jim Gunn working on the electronics for the CCD cameras that they attached to the 200 inch 'scope (described in Preston's "First Light").  


Once again, sorry if readers outside the U.S. have trouble with this link.  I hope you all can find other ways to see this video.  


http://www.hulu.com/watch/76165

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SolderSmoke Book Review: "The Day We Found the Universe"

    I find myself reading a lot of books about telescopes and cosmology.  I guess this is related to the desire to pull weak DX signals out of the noise. And I like the descriptions of the gear used to pull info out of the star light.  These are, after all, big antennas.   

    I really enjoyed this book by MIT's Marcia Bartusiak. She describes humanity's effort to find our place in the cosmos.  As she points out, the conventional wisdom seems to be that until Edwin Hubble came along everyone thought that the Milky Way was the universe.  As it turns out, it is not that simple -- going back to the time of Kant, there were scientists who suspected that the nebula that were showing up in telescopes were in fact "island universes."  Bartusiak takes us through the ups and downs of this idea, and in the course of the book provides some really great descriptions of the astronomers involved in the struggle to understand the nebulae.  Most of them were great people.  Others, well, not so great.  George Ellery Hale comes out as one of the heroes, and Bartusiak seeks to refute the notion that Hale was schizophrenic -- he was clearly suffering from depression, but Bartusiak says that the story about him being advised by a "little elf" was just an oft-repeated myth. Edwin Hubble gets a decidedly mixed review.   

My guess is that the title was selected by the publishing company's marketeers, and I think it was a poor choice:  the whole point of the book was that we didn't find the universe in one day.  It took a lot longer than that!      

Anyway, if you are looking for a good summer read, I recommend this book.  You can get a copy through the link above. 

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A Father's Day DX-100 Story

Warning:  In this post we are DEFINITELY leaving the world of QRP.  There is nothing even remotely QRPish about the Heathkit DX-100.  This rig is all about power. And weight.  Heavy metal, plate-modulated power.  And weight. 


Back in February of last year, John, K2ZA, and his wife Erika drove down from New Jersey to give me something very special:  the beloved Heathkit DX-100 transmitter of John's (SK) dad.  Here's the report on that memorable day:
http://soldersmoke.blogspot.com/2011/02/k2zas-dx-100-arrives-at-soldersmoke-hq.html   


I meant to get the rig on the air right away, but I got distracted by other projects.  Well, this week I decided to get going.  I ordered a new can of Caig Deoxit D-5.   I removed the screws from the front and back of the old rig and carefully (for the sake of my fingers and toes!) pulled it out of its cabinet. 


I found it to be in remarkably good shape. There was a bit of dust and some of the tubes were a bit loose in their sockets, but otherwise it was perfect. 


John's dad had made some mods to the old rig.  The most noticeable were on the front panel.  He got rid of the old plastic Heathkit knobs, and he had added reduction drives for the driver and amplifier tuning caps.  My first instinct was to try to take this rig back to original form, but over time, as the rig sat on the bench, I came to appreciate the work that John's dad had done.  I decided to keep the rig as he had left it. 


John's Dad used this rig on RTTY.  He has an FSK stage attached to the oscillator circuit.   

He also added a very useful VFO "spot" or "net" push button switch on the front panel. And he put a T/R relay in a box on the back of the cabinet.  Useful mods, all nicely done. 


After the cleanup, of course I couldn't wait to get the rig on the air.  Using my old Dominican Republic HQ-100, I fired it up yesterday afternoon on 40 CW.  On the first call I worked KK4RF in Suffolk Va. Then I went to 40 AM and worked a bunch of guys there.  Later I went to the real heartland of heavy metal AM:  75 METERS!  Yea!  They tell me the old rig sounds great.  


This has really been fun.  Thanks John.  Happy Father's Day. 

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Long Lost Varactor Receiver Found!

SolderSmoke fans will recall that for a long time I have been looking for the radio magazine article that propelled me into a  receiver construction project that failed and left me tech-traumatized. I tried to build a solid state receiver back in high school.  All I remembered about it was that it was direct conversion and varactor-tuned.  And that I couldn't get it to work. I think the problem was in the oscillator.   

Well, I think I found it.  Chuck Adams and the qrp-tech guys were talking about a receiver project and someone mentioned the old Herring Aid Five, a receiver companion to the famed Tuna Tin Two.  That got me thinking.  The time of publication was exactly right: July 1976.  I had just graduated from high school.  This morning I renewed my ARRL membership and then immediately accessed the QST archives.  Sure enough, the Herring Aid Five is varactor-tuned.  That has to be it. 

So this one is now definitely on my to-build list.  I will finally get this receiver working.  Sometimes projects take a long time...  Thanks again to all those who helped me in this search. 

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