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Tuesday, October 6, 2015

The Advancement Of The Radio Art and The Enhancement of International Goodwill

U.S. Code of Federal Regulations
 
PART 97—AMATEUR RADIO SERVICE
Subpart A—General Provisions
§97.1   Basis and purpose.
The rules and regulations in this part are designed to provide an amateur radio service having a fundamental purpose as expressed in the following principles:
(a) Recognition and enhancement of the value of the amateur service to the public as a voluntary noncommercial communication service, particularly with respect to providing emergency communications.
(b) Continuation and extension of the amateur's proven ability to contribute to the advancement of the radio art.
(c) Encouragement and improvement of the amateur service through rules which provide for advancing skills in both the communication and technical phases of the art.
(d) Expansion of the existing reservoir within the amateur radio service of trained operators, technicians, and electronics experts.
(e) Continuation and extension of the amateur's unique ability to enhance international goodwill.

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On a recent podcast I mentioned that I like the phrase "the radio art."  I also mentioned that I heard some objections to this term.  A couple of guys wrote in on this --see below. 
I found out that the phrase features prominently in Part 97 of the U.S. Code of Federal Regulations.  This is the document that establishes ham radio in the U.S.  (see above)
I really like the last line of the first section of Part 97: e) Continuation and extension of the amateur's unique ability to enhance international goodwill.  Yea!  That's us!  The International Brotherhood of Electronic Wizards! 

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Bill:
Was listening to episode 180 and heard you mention that some people had taken exception to using the label “Art” for radio electronics.  You should refer them to the Webster’s definition of art,
 
art. noun \ˈärt\ : something that is created with imagination and skill and that is beautiful or that expresses important ideas or feelings. 
 
Often the patent office, much older than radio, will invalidate a patent application based on “prior art”.
 
Keep up the great podcast!  As soon as I finish a couple of other projects, I’m going to try to build Pete’s LBS design.  First, I have got to get a mobile rig installed in my new truck, commuting without it is just too boring.
 
72,
Don
WD4ON
 
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Bill:
I was listening to episode #180 on the on the way into my office this morning and wanted to send you a quick note on the phrase "radio arts." Another example of why "art" is indeed the proper term is that the United States Patent Office (USPTO) classifies patents into, you guessed it "Art Units": http://www.uspto.gov/patents-application-process/patent-search/understanding-patent-classifications/patent-classification .
For example, Art Unit 2621, Class 178 - Telegraphy (http://www.uspto.gov/web/patents/classification/uspc178/defs178.htm) which is related to Class 455 Telecommunications (http://www.uspto.gov/web/patents/classification/uspc455/defs455.htm)
and many many more as you can well imagine.
Going even further, the basis for our patent system is in Article One, Section 8, Clause 8 of the US Constitution:
"To promote the progress of science and useful arts, by securing for limited times to authors and inventors the exclusive right to their respective writings and discoveries;"
Which in turn was the basis for the first patent statute, The Patent Act of 1790: http://docs.law.gwu.edu/facweb/claw/patact1790.htm
Keep up the good work in furthering the radio arts!
73,
Tim
KA9EAK
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Monday, October 5, 2015

AK2B's Beautiful Si5351 Receiver -- Just Listen and Watch!



Tom Hall does amazing things with solder and electrons in the heart of New York City.  I give him extra credit for doing this on the island of Manhattan because 1) that's where I'm from and 2) EVERYTHING is more difficult there.

I may have presented this video before.  If I didn't, I should have.  And if I did, well, here it is again (I guess my NYC attitude is showing here).  

Look at the ease with which Tom switches bands.  Fantastic!  But even more important, LISTEN to the quality of the reception.  Listen as Tom tunes in on strong CW and SSB signals.  Do you hear any signs of the dreaded phase noise that is supposed to plague the Si5351 chip?  I do not.  I think this receiver sounds great.

I don't know why the Si5351 got such a bad rep for noise.  Could it be that some people were testing it with boards other than the Adafruit or NT7S products that we have been using?  Could it have been that in the tests the boards weren't completely installed?  (It is important to have the VFO and BFO signal lines properly shielded.)  Could it be that in the tests they were using physically adjacent clock outputs from the board?  (We use CLK0 and CLK2, skipping CLK1 to avoid the "bleedover" problem that was noted by early users.) 

Saturday, October 3, 2015

SatNOGS: 3D Printed Az-El Rotators! Ray-Gun PVC Helical Antennas! Arduinos! Dongle Receivers!



Wow, this project is very appealing. Finally, a 3D printer project that seems truly useful.  They are using one of the Dongle receivers we've been playing with, and, of course, Arduinos.  You could really geek-out with this stuff.   Check out the hardware side of this effort here:
https://satnogs.org/documentation/hardware/

Friday, October 2, 2015

Another Free Kindle Book

Bill's New Book!

As a result of Elisa's suggestion, more than 1300 people downloaded the free Kindle version of "SolderSmoke - Global Adventures in Wireless Electronics."   I hope they liked it.  If you did enjoy the book, please spread the word about it  (you can use the e-mail button below to forward this post to friends and relatives), and please put a review on the Amazon Kindle page. 

In the course of following up on Elisa's idea, I discovered that Amazon Kindle has a program that will allow me to make my more recent book available for free (for a limited period).  

So the Kindle version of "Us and Them -- An American Family spends Ten Years WITH FOREIGNERS"  will be available for free from October 3 through October 7.   Please send me feedback,  please let your friends and relatives know about the book (again the e-mail button below is good for that), and please post reviews on the Amazon page. 

You can find the Kindle book here.  It will be free from October 3 through October 7, 2015 

http://www.amazon.com/gp/product/B00L8DR4RK?*Version*=1&*entries*=0



  

Old Spark (But Thankfully Not Forever)


For the last couple of weeks I have been plagued by noise on the HF bands.  In spite of being in a very built-up area of Northern Virginia,  I usually have low noise levels.  But for the last couple of weeks I've had intermittent but frequent arcing noise.  It sounded like classic power line arcing. 

My 17 meter Moxon antenna provided a clue as to where it was coming from:  As I spun the antenna around, the noise was always a lot stronger to the North-North West.

On Wednesday morning on the way to work I noticed that the fire department and the power utility were working frantically on a pole about a mile from our house.  It had obviously been on fire -- it was still smoking when we went past.

When I got home I was pleasantly surprised to find the arcing noise gone.  It took me a few minutes to make the connection -- yes, the smoking power pole was to my North-North West. 

OBVIOUSLY THE RADIO GODS CAME TO MY ASSISTANCE!

This was a good demonstration of the fine front-to-back characteristic of the Moxon antenna.  And a reminder of what radio signals sounded like in the days of spark. 

  

Thursday, October 1, 2015

Bryan KV4ZS's "Let's Build Something" Direct Conversion Receiver



Bryan: 
 
I think it sounds great!  There is nothing really wrong with it -- that is what 40 meters sounds like!   Sure there is static.  And those whistles you hear near the top of the band are the carriers from shortwave broadcast stations.  You might have a little hum, but that should disappear once you get it all packaged in a metal box.   Congratulations Bryan!  You have done something that very few hams have done:  You have built a receiver. 73  Bill N2CQR
......................
 
Hi Bryan,
 
First let me congratulate you. That is one fine build and you may actually have absolutely nothing wrong!!!!!! I really must applaud your “squares”. They look like they were made on a CNC machine. Bravo!!!
 
You are operating the LBS without an RF amplifier and as such you are trying to make up the gain in the audio amp. I would say that the results you are hearing are very consistent with the DCR without an RF amp. Get the RF amps stage working and then run your test –you will find with the RF amp that at the gain setting you have for the video will be room filling. It actually sounds pretty good. You might also try connecting a 1 NF across the audio trimmer pot as that will cut down on the “hiss’ sound.
 
Concentrate on the RF amp stage and then re-run your test –you will see the difference.
 
Great build – very nice job.
 
73’s
Pete N6QW
 
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Very nice!
 
Sounds pretty good to me in terms of noise – that’s what a direct conversion receiver sounds like (they tend to be very wide in terms of reception – static is normal... Welcome the world without noise reduction and DSP!!).  DCR’s – because they are not run through a narrow IF filter – allow a very broad range of signals to get to the audio stage. So, for example, if you tune that around during a CW contest, you’ll hear a LOT of signals at the same time – versus only one or two at a time, once you have this run through the 4.9152 crystal filter. That’s the nature of the beast.
 
The 1nf across the audio trimmer definitely will help with reducing the hiss, although I must say my Kenwood receivers all have a similar amount of hiss and I prefer my radios with more, not less, noise (it lets me know what the band conditions are like...). I have noticed on my builds, however, that if you have a very, very high pitch WHINE on the other hand, that tends to be a bad solder joint or bad capacitor somewhere – probably on a capacitor – introducing an offset into your RF someplace it shouldn’t. What that looks like on an oscilloscope is the audio signal will have a large DC offset versus ground – almost always a bad solder joint on a capacitor—or a bad/broken capacitor--somewhere in the audio amplifier. That’s the same problem you get when you try to record audio sometimes from an external source (TV, radio, CD player) on your computer – DC voltage offset on the audio line. Kind of like what you might have heard on a stereo if you ever tried to switch to a channel where the input was hanging open.
 
Ben
KK6FUT

Wednesday, September 30, 2015

Alan Wolke in the Dinosaur Den (Video)



Very cool.  But it makes me sad that my Tek 465 broke (and I can't fix it!).

Tuesday, September 29, 2015

Jac's Homebrew Receiver (video)

 
Jac (KA1WI) and I spoke on 40 meters on June 29th.  I told him about the BITX -- he said he liked the idea of building something and pledged to start melting solder.  This week I got this message and video from him.  Good going Jac!  That was fast! I think we all know who designed the IF amp:  Wes W7ZOI.   As for the DS/PLL, I recommend you take a look at the Si5351 with an Arduino microcontroller.

Hi Bill,
 
I started in July building a receiver with the available parts I had collected over many years. Finally today the receiver is working more or less to my satisfaction. Here is a brief description. 
 
I am using a set of crystall filters from an old Atlas 350XL, 5.595 is the IF frequency and the filters  have independent USB and LSB plus CW 500 Hz filter. The radio set is a single conversion type. A DBM at the front end and as product detector. Keeping the BFO signal from leaking is a challenge but I managed by carefully matching the three ports of the DBM used as product detector. Matching the IF filters impedance was another challenge. Following the DBM there is a LNA amplifier using a 2N3866 and I am trying another LNA with a discontinued Siemens BFT66 transistor with a very low noise figure. I have some experience with those and they can be amazingly quite. 
 
The IF amp is a hybrid cascode with three stages and AGC that I found in the internet designed by a well known  OM, the design works very well it is easy to make and is very stable despite its nearly 70 dB of wide band gain. The AGC range is close to 100dB . . .
 
The front end has 6 BPF covering from 1.5 to 30 Mhz all switched by relays. This unit I got from an old German receiver. 
 
The VFO or 1st LO is a DDS unit I had played with years ago. From N3ZI is far from perfection but it does the job when the bands are alive and well. The alternative to the simple DDS are complicated. I wish there were more DDS PLL kits available. It can take a long time to get a full synthesizer satisfactorally working. 
 
The set is made of mechanical parts from a Tektronix main frame instrument, there are many parts of different shapes that can be attached together in a crazy way but certainly very functionally. There is the IF amplifier and the Product Detector BFO enclosed in two brass silver plated boxes, both also recovered from some surplus ages ago. The DDS is one of the sides on the chassis without any shielding.
 
The IF filters and the front end are going to be attached to the rear of the chassis by just adding brackets etc., you get the idea. I am glad the video is acceptable.  
 
I thought it will interest you know that at age 70 is also possible to roll your own, despite having to check every solder joint since my eye sight is the biggest  problem 
 
I have other projects, another receiver with an IF of 9 mHz with SSB and AM filters using another type of high gain IF amp. 
 
Best 73’s de 
Jac
 

Monday, September 28, 2015

First Ever SSB Homebrew to Homebrew Contact by N2CQR. With...

2322 miles.  3737 kilometers

Pete Juliano and I were talking on Skype yesterday evening.  He was regaling me with tales of the wonders of his new beam antenna.  He mentioned that he was working a lot of East Coast stations... Wait a minute, I thought, I'm an East Coast station.  And I have a 20 meter rig sitting right in front of me.  "Meet me on 14.190 Pete!"   It took me a minute or so to get the rig connected to the CCI amplifier and the 20 meter dipole.  By the time I got everything fired up, there was a station on the frequency.  I thought we'd lost the spot.  But no!  I realized it was Pete calling me. 

This was extremely cool.  Pete was using his ZIA rig with the brand new beam.  I was on my VFO BITX20.  And I was using the CCI amp that Pete had coached me on (he taught me how to tap the holes for the heat sink).

This was the first time I had ever contacted another homebrew SSB station -- and the first time Pete and I had spoken on the air.  THE RADIO GODS WANTED THIS ONE TO HAPPEN! 

I recorded the QSO:

http://soldersmoke.com/n6qwn2cqr.mp3

I will ask Pete to provide more detail regarding the California end of this QSO in the comment section below.  Did you have your amplifier on Pete?

Saturday, September 26, 2015

Pete Experiences the Joy of Rotation

20150925_111023[1]


Read all about it (and see the videos):  http://n6qw.blogspot.com/
Congratulations Pete!

Friday, September 25, 2015

Civility, Ham Radio, King Hussein, and the International Brotherhood


Hi Bill,

Interested to hear you talking about civility ... My introduction to amateur radio was via a Heathkit GR 64 and Roy, G3PMX. When I finally took my ticket - 1970, and passed, I called him on the phone to tell him - he told me to come on up to his QTH, I did, via an old bike taking about 30 minutes to get up the hill. When I got there, he put me on the mike, the guy the other end was really great, talked about being a part of an international brotherhood and a movement for world peace - just a magical first contact ...

Roy asked me if his call seemed a little odd, it did, it was short, JY1, but I was really slow to cotton on to who I'd just spoken to... What really blows me away to this day was that the King of Jordan sat in his shack and waited for a 16 year old kid to pedal up the hill just to give him a fantastic first contact ... My only regret is that I never got to speak to him again to say "thank you" - when you talk about legacy radios, it isn't the tech that we need to hold on to, though we do, it was what that man did to reach out to a fellow amateur.

 
By all accounts, he was a fantastic guy, he used to sit at Roy's kitchen table drinking coffee and just being one of the guys ... Sadly I was at sea by then hence not meeting him.

Roy knew him because he worked for Marconi & put the antennas on the palace, Hussein just appeared having that Roy was an amateur and they had a long conversation about radio - when he turned to leave, Roy asked his name so that he could stay in touch - Hussein told him to just ask for Hussein the radio guy - never let on that he was King ...

 
Roy said that on several occasions, JY1 travelled to the UK more or less incognito and hired fairly innocuous cars to get about the country simply because he was here as an amateur, not a head of state …
 
I really do regret that I never got the chance to say “thank you” to him – it was the sort of gesture that I have always thought typifies what you have tried to support and continue, and is indeed carried on by the likes of Joe Taylor who once took the time to respond to an email from me explaining how to set a WSPR system up despite being Nobel Prize winner !! 
 Great example of the spirit of amateur radio transcending all else :-)

 73s, Nick, G8INE
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