Posts Tagged ‘homebrew’
Antique Wireless Association Journal – On-Line
I recently featured some material available from the Antique Wireless Association and had to go a little deeper.
They have a wealth of information available on their site with some of their journal’s online articles. Great articles on vacuum tubes and such – but much, much more.
I found a great little article called “Working With Crystal Control: A ‘Part 15′ Broadcast Band Transmitter “, the transmitter setup on the left. Really neat article (I think I must….want to build one of these)……… The image on the left is from that article – not to difficult to build and learn!!!
As I understand it, you can purchase a CD with back copies of this magazine. I just might look into that. Kinda sounds like the enjoyment I get when I receive that little journal from the G-QRP club – SPRAT. When that hits my mailbox, I know it’s getting stuffed in my backpack for enjoyment down the road.
One important thing to keep in mind with the AWA Archives is how well they not only demonstrate radio history, but how you can recreate it and learn from it. What a better way is there for a budding QRPer to learn where he’s going, but get a hands on demo from where other hams have been?
Below are only a few examples of the neat articles you’ll find on the AWA website:
Key and Telegraph by John Casale, W2NI
President Taft’s Telegraph Key
Building a 1929 Style Hartley Transmitter by Scott M. Freeberg, WA9WFA
Need a transmitter for our 1929 QSO Party? Build it in one week-end!
Breadboarding by Richard A. Parks
More Adventures With Transistors
The Vacuum Tube by Ludwell A. Sibley
Tube Bases and the Asbestos Hustle
Restoration of Shellac Finishes on Older Radios by Lane Upton
Don’t Strip That Old Finish–Save it Instead!
A nostalgia trip for the old-timer; an eye-opener for the newbie.
The Beginnings of Radio Central by Ralph Williams with Marshall Etter, Bob McGraw and Chris Bacon
Pupin and Armstrong lay an egg–An Antique Radio Gazette reprint.
A Solid-State Filter Choke or Field Coil Replacement
Go ahead and check them out at:
http://www.antiquewireless.org
http://www.antiquewireless.org/otb/archive.htm – a direct link to the journal archives
A simple HF receiver
Before this blog I had a web site with some amateur radio information. It is still out there, but I should close it down or update it totally. Here is one of the projects from those pages which I had great fun with and which is worth adding to this blog. I was quite impressed with the quality of the audio from this receiver which has just seven components (three capacitors, two transistors, a resistor and a transformer). Below is an edit of what was originally written a few years ago.
I constructed this simple receiver having seen the circuit at WB4LFH’s web site which he calls the ‘audion’. This circuit is almost identical to the last circuit on that page, except I changed the inductor connection to the variable capacitor from being a tapped connection to being a transformer coupling.
The inductor was a T50-2 toroid with secondary being 28 turns of enameled copper wire and the primary (connected to the antenna) being two turns. (Remember a ‘turn’ on a toroid is the passing of the wire through the hole). The transistors were 2N3904 types, but you can try any general npn transistor. The tuning capacitor was a air plate type taken from an old radio receiver, likely about 300pF. The circuit was constructed ‘ugly style’ on a small piece of unetched circuit board. Use what you have in your junk box and experiment.
The performance is very good considering the simplicity of this receiver. Below are a set of sound recordings from this receiver. The recordings show how the volume can change (no AGC here!) and that the selectivity is not too good.
If you consider building this receiver please note that these recordings were done with the receiver connected to my external antenna at that time, a G5RV. I tried using a long whip antenna, which I had in the junk box, and there was no discernable reception of a signal with it. So you will likely need to use a good length of wire to act as an antenna. Post a comment if you have any success with this circuit.
Polar Bear on Hontoon Island
Look out Hontoon Island the Polar Bear of Florida is coming your way! Good Friday, 2 April 2010 Polar Bear QRP member #173 (aka K4UPG) will attempt to qualify Hontoon Island as a US Island on the Air by making 25 contacts including at least 2 DXCC entities.
Activity will start about 1400Z after the ferry ride over to the island. Plan is to use special callsign K4T for recognition.
Look for us on 30m cw (10.106-10.116 MHz) and 20m cw 14.050-14.070 MHz and on the hour we will check 15m 21.060-21.070. If anyone shows up to assist, will also attempt ssb on 14.250-14.260 MHz island corridor. All ops will be QRP so we’ll need your help to pull us out!
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If things go well, our Central Florida QRP group may consider this as a new operating site! If you are in the area, come on and check it out with us.
Thanks to Florida State Parks for the fine pictures!
P.S. We did it 4.2.2010! Over 30 QSO’s update coming! I am TIRED!
















