Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Serving the worldwide community of radio-electronic homebrewers. Providing blog support to the SolderSmoke podcast: http://soldersmoke.com
Podcasting since 2005!  Listen to our latest pocast here:
Podcasting since 2005! Listen to Latest SolderSmoke
Tuesday, January 31, 2012
Some Audio Shielding
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Monday, January 30, 2012
My .02 KW Linear Amplifier
My Cycle 23/Cycle 24 refurbishing project continues. The JBOT amplifier in the 17 meter SSB rig is now working nicely, but unfortunately just as I got ready to make some contacts, the Coronal Mass Ejection hit us and conditions on 17 deteriorated badly. Looking for something to do, I noticed that in some pictures of my old Azores station, sitting alongside the SSB transmitter there was a small cabinet with a QRO/QRP switch on the front panel. Ah yes! My Ramsey Kit linear amplifier! This is a MOSFET-based device. Mine was designed for 20, but I changed the low pass filter and put it on 17. Later, in Italy, it went on 20 meters and for some reason I went back to the 20 meter low pass filter.
Yesterday I blew the dust off this thing, pulled out the 20 meter LP filter and replaced it with a filter that will let my 17 meter RF reach the antenna. Today I fired it up. Wow! 20 Watts! Look out 17 meters!
I really like the QRO/QRP switch -- it gives me the opportunity to lean back and say (just like the big guns) "Wait a second Old Man, let me turn on my LINEAR!" I even have a little fan in the box that you can hear when I go to the QRO position. Unfortunately it doesn't make the lights flicker. But we can dream...
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Sunday, January 29, 2012
Putting 17 Meter SSB Station On the Air
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Saturday, January 28, 2012
A Good Deal on SolderSmoke -- The Book 30% off!
Thirty percent off from Lulu!  That's pretty good!  Offer ends on January 31.  See "SolderSmoke -- Global Adventures in Wireless Electronics" at:
http://soldersmoke.com/book.htm
Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Friday, January 27, 2012
Some Amazing German Knack

Michael, DL4MGM, sends us this report from a country in which "the knack" has deep linguistic and cultural roots. Wow, that's my kind of hamfest! Test stations for homebrew gear. And the key-powered transmitter is a great idea. I know there is a lot of energy going into those straight keys -- as a kid, my arm would hurt after an afternoon of unanswered CQs. Thanks Michael!
Hi Bill,
I do not know how big your german listener base is but in any case I want to draw your attention to the "Amateurfunk Tagung München" on 10th and 11th of March 2012. It is a german amateur radio convention which takes place every other year at the University of applied sciences in Munich. There is one speaker track with, mostly german, talks on a wide spectrum of topics related to our hobby. The organisers did a particularly good job in getting Joe Taylor, K1JT, as a speaker to talk on "Recent Advances in Amateur Weak Signal Communication" (10. at 17:00 local time). Needless to say that I'm looking forward to this. Apart from the talks there will be booths and exhibits from various groups and also some well known commercial sources of RF/microwave components, modules and the like.
Another highlight are the lab places, including personnel, where you can have your home brewed stuff tested up into the high double digit GHz range. I always take home new ideas from just strolling around there and looking at the things people bring for testing...
The last thing I want to mention is the current "operating and construction challenge" because it so right up our alley. It is something like an "Energy harvesting transmitter key". The task is to build a 2m, 80m or 10m transmitter which is completely powered by the energy put into the key movement. In order not to stifle inovations, a lot of liberties are granted such as keying by foot. It will be allowed to pre-charge the energy storage component by keying up to to 10 "v"s with the transmitter turned off. As proof of operation, a 160 character random text message will have to be send to an adjoining room. Ranking criteria (in descending order) will be: - Peak transmitter power during transmission of the last character. - Construction and handling - Message errors - Keying speed / total transfer time - Tone quality and frequency stability Sounds like it will be a lot of fun... Here the link to the german site: http://www.darc.de/distrikte/c/amateurfunktagung-muenchen/
That's all for now.
Keep going!
Kind regards from southern Germany de Michael, DL4MGM
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Wednesday, January 25, 2012
Toroidal Travails II
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Tuesday, January 24, 2012
Toroidal Transformers: Does Size Matter?
I noticed something similar on my previous JBOT: performance improved when I switched from some relatively large binocular cores and went to the recommended FT-37-43.
So, what do you guys think? Could there be lower losses using the smaller cores? Any other reason why the smaller transformers seem to be doing better?
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
Subscribe to:
Comments (Atom)