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Saturday, June 20, 2015

Another Great Rig (and Video) from Peter Parker VK3YE



Peter Parker has a double dose of The Knack:  Not only is he a great rig builder, but he is also a very skilled teacher.  His videos provide really excellent descriptions of how he selects, designs, and modifies the stages that make up his magnificent rigs.  You can learn a lot from these videos.  Thanks Peter.  

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Friday, June 19, 2015

Why are relays marked "K" on schematics?





Our official SolderSmoke etymologist and lexicographer Steve Silverman explains:

Bill

    Here is some ham radio/electronics trivia
    In the days when amateur radio used short range spark transmitters, multi-station relays were used to move a message across longer distances.  At the end of each transmission, a "K" was sent, which told the receiving operator to commence his relay to the next station. Hence the use of 'K" to designate a relay in a schematic diagram, and "end-of-transmission" for CW operators.  And hence the American Radio RELAY League

73
Steve Silverman
KB3SII  ... .. ..


Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Thursday, June 18, 2015

Progress on Pete's "ZIA"


It is practically SPARKLING!   Beautiful job Pete.  I'm glad you are actually boxing this one up! 

Pete has many more pictures of this project here: 
http://www.n6qw.com/TIA.html

He also notes that there may have been some sub-conscious Knack wisdom at work when I dubbed his rig "The Zia."   I was thinking strictly in terms of language and ethnic heritage:  TIA stands for Termination Insensitive Amplifier.  But in Spanish it means "aunt".  But in Italian Aunt comes out as Zia.  So Pete's should be a Zia, right?  Capisce?

Well Pete puts an electronic twist on it:

"Once again you are spot on with ZIA (With  Z the electronic symbol for Impedance).  Thus Impedance (The symbol Z) Insensitive Amp. Thank You."

 Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Wednesday, June 17, 2015

20% off Sale on "SolderSmoke" and "Us and Them" Books at Lulu

Treat yourself to 20% off all print books with code SPLURGE. Offer ends June 18th at 11:59 PM.

20% off on all print books at Lulu through June 18:
 
 
Use coupon code SPLURGE
 

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Sunday, June 14, 2015

Finally! An Award for QRP DSB! VK3YE's 40-40 Award



Brilliant!   Great stuff!  Lots of fun! 
Another great idea from Peter Parker, VK3YE.

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Saturday, June 13, 2015

SolderSmoke Podcast 177 Bicoastal Termination Insensitivity Unphased by Phase Noise

 
SolderSmoke Podcast #177 is available:
 
 
13 June 2015
 
-- PETE JULIANO INDUCTED INTO THE QRP HALL OF FAME
-- Bench Reports:  Bicoastal Bilateral Success:  A Tale of Two Tias
    Only 3 TIA rigs in the world?  It depends...
    Relay improvements in the BITX Builds
    Straightening out amp problems
    The many uses of copper foil
    No phase noise or bleed-over troubles
    Plug-in filters
    Adjusting TIA amp gain on RX and TX (too much is not good!)
    Getting the BITX to work with the CCI amp
    Allison wisely prescribes 3 db pads 
    Curing hum by moving the power supply (duh!)
-- Farhan's New Minima -- Crying out for an Si5351?
-- Mike KL7R's Web Site is Back (thanks to W8NSA)
-- SolderLex: Rigs or Radios?  We go with Rigs
-- A ham rite of passage:  Build a Dipole!
-- What does your shack look like at the end of a project?
-- MAILBAG 
    The CORRECT pronunciation of Belthorn
    Multiplication and Division by 4
    W8NSA, Vietnam, a Transoceanic and a 9V Battery 

 






Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Tuesday, June 9, 2015

Termination Insensitivity -- Only Three TIAs in the World?


Termination Insensitivity.  Is this like when your girlfriend dumps you and you just don't care? 

No. It's more like this:

http://www.n6qw.com/TIA.html

Wes Hayward and Bob Kopski developed the Termination Insensitive Amplifier circuit back in 2009.  With a bidirectional rig it is important that the crystal filter face the same impedance in both directions.  Simpler bidirectional amps are impedance "transparent" in that their input impedance depends on what is on the output (and vice versa).  The circuit that Wes and Bob developed solved this problem:  these amps always look like 50 ohms.  That's very useful.  When I was building my earlier BITX rigs, Farhan suggested that I try the termination insensitive amp circuits.  On my latest project I followed his suggestion.  At the same time, Pete was building a new BITX, also using the TIA amps. 

Pete wrote to Wes and Bob and asked if anyone had followed through on their 2009 article by building a rig using this circuit.  Wes said that he was unaware of any TIA rigs.  It turned out that Tom Hall up in New York City had built one (video below). So I guess Pete's rig is TIA 2 and mine is TIA 3!  (But I was thinking, because of Pete's Italian ancestry, shouldn't we call his rig a Zia?)
Please let us know if you know of any other TIAS (or ZIAS!) out there.

Here is Tom Hall's very FB TIA:



Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Friday, June 5, 2015

BITX DIGI-TIA Build Update #7: On The Air!

 
With lots of encouragement from Pete, I finally got the BITX DIGI-TIA on the air.  The first contacts were made yesterday. I have it on 40 meter SSB.  The finicky denizens of that audio-conscious band seemed to like the sound of the rig.   I was almost reluctant to tell them it is homebrew (no need to stir up trouble!)
 
The plug in filter arrangement seems to work very well.  This will allow me to put this rig on many other bands.  All I have to do is build some additional filter boards and upload modified versions of the software.  There is even space to make a plug-on socket for the crystal filter (the 9 MHz IF would not be cool for 17 meters).  
 
I'm really pleased with the RF power chain (the original BITX chain).  This time I built it all in a straight line along the back of the transceiver with lots of attention to shielding and grounding.  There were no instability problems.  The amplifiers did not try to be oscillators.  I was shocked!
 
I did have to reduce the gain of the three termination insensitive transmit amplifiers. Using the chart in the 2009 Wes Hayward/Bob Kopski article,  with just a few resistors you can set the gain.   I had built them with 19.4 db gain each.  This turned out to be too much -- the slightest amount of audio into the SBL-1 was driving the amplifiers to peak output.  So yesterday I changed all three amps to 15 db (I think that was what Farhan had in the original BITX).  It only took me about 15 minutes and it seemed to take care of the problem.  I am getting 7 or 8 watts out of the IRF-510.
 
T/R switching is very smooth and quiet using just two small 12V relays.
 
Thanks to Pete for the mil-pad boards and the encouragement (especially on the use of the Si5351).  Thanks to Farhan for the BITX architecture. Thanks to Steve Smith for the Yaesu filter.  Thanks to Wes and Bob for the TIA circuit.  Thanks to Thomas in Norway for the Si5351 software.  And Thanks to Allison for all the good advice.

 




Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Thursday, June 4, 2015

Moonbounce, Meteors and French Radar in Scotland

David GM4JJJ was the fellow who sent us the video of early Scottish moonbounce ops.  This morning he sent me a tale of woe involving some transverters and several BASTA! moments.  I will spare you all the painful details, but I really liked this paragraph about David's use of sigs from a French space surveillance radar:  

... While the transverter for 144 MHz was being tested out into my new homebuilt antenna I tried receiving the French space surveillance GRAVES RADAR on 143.050 MHz. It is easily detected here in Scotland via meteor scatter. It is also so strong that passing space hardware like the ISS reflect the RADAR and can also be detected, showing up on FFT displays with their rapid Doppler shift.  GRAVES is also easily detected by moonbounce, I could see it and hear it on my single 10 element yagi pointed at the horizon without a preamp. Even when the moon was at 15 degrees elevation here, and even higher in France the signal was strong enough to be picked up in one of the lobes of my antenna. You can actually see what the vertical pattern of the antenna looks like as the moon rises through the peaks and nulls of the antenna in conjunction with the constructive and destructive interference patterns caused by ground reflections and the direct path to the moon.

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Wednesday, June 3, 2015

Rigs vs. Radios: A Real RIG in a Real SHACK



Earlier this year Pete and I were talking about the use of the word "rig."  For me this is a hallowed term that captures much of the essence of ham radio.  Sadly, in modern parlance "rig" seems to be increasingly substituted by word "radio." If you are wondering what the difference is, well, I think this video presents a good example of a rig. 

There was a nice exchange of e-mails on QRP-L about this video: 

Jun 2 at 9:54 PM




Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
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