Feynman at G-QRP Convention!

What do Richard Feynman and the G-QRP club have in common?

The answer is an annual pilgrimage to Ripponden in Yorkshire, England. The G-QRP club have their convention in a local school and Feynman went there every summer to visit his wife's family. Here's an interview with Feynman filmed at the Old Bridge Inn which is about a mile from where the G-QRP club gather:

http://www.openculture.com/2012/11/richard_feynman_talks_physics_in_take_the_world_from_another_point_of_view.html

Is this enough to make Ripponden the Knack Centre of England?

Regards,  Alan G0RWB

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

Yikes! Screeching Transistors Throwing off Blue Light!

I found a quote from Doug DeMaw that I wanted to share.  This one seems appropriate as I struggle with unwanted oscillation (and as Halloween approaches). From the January 1986 QST:

"Self -oscillation occurs not only in the low-frequency and high-frequency spectrum, but it often takes place at audio frequencies!  I have actually heard the transistors "screeching" when strong audio oscillations were taking place in a homebrew transistor power amplifier. On one occasion I could see a bluish glow coming from within the transistors (visible through the ceramic heads of the devices) during a period of instability.  Needless to say, the transistors self-destructed."

I've been having some instability problems with my BITX 17 IRF510 final.  But I think I have the problem identified.  I was getting low frequency oscillations (around 100 KHz).  Tonight  tried putting the IRF510 on a separate power supply.  The oscillations ceased and I am getting a nice clean 3 watts out.   So I'll go back and beef up the decoupling on the power supply lines.


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

20% off on SolderSmoke Book

Just use the coupon code PUMPKINS at checkout:

http://www.lulu.com/spotlight/soldersmoke

(You can also use this coupon to buy Grayson's "Hollow-State Design" :
http://www.lulu.com/shop/grayson-evans/hollow-state-design/paperback/product-20987562.html

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

SolderSmoke Podcast #155 BITX17, TEK465

Podcast # 155 is available for download (or you can listen by clicking on the button above):
http://soldersmoke.com/soldersmoke155.mp3

October 14, 2013  (Delayed Back-to-School edition)

Topics covered:

-- BITX Beauty -- Building a BITX17

-- VFO woes, and the wisdom of Doug DeMaw's love for crystals

-- Why does a 55 year old man NEED clear nail polish varnish?

-- How the VFO KILLED the Tek 465

-- Trying to fix the Tek 465 (not for the faint of heart)
 
-- New products:  Justin Beiber Duct Tape, bifocal safety glasses,
magnetic reading glasses, Ward Silver's new book

-- Backwards British Bike Brakes

-- MAILBAG 

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

"Robert Ford -- A British Radio Operator in Free Tibet..."

http://www.economist.com/news/obituary/21587201-robert-ford-british-radio-operator-free-tibet-died-september-20th-aged-90-robert-ford

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

Nice Slide Show on BITX

https://sites.google.com/site/arvidevans/BITX_QRPacificon..pdf?attredirects=0


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

BITX BUILD UPDATE #13 -- VIDEO TOUR

I hope to get the next podcast out within a week or so.  The BITX has been keeping me busy!


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