Monday, May 28, 2012

A New Soldering Iron

This year at the Dayton Hamvention 2012 gathering I decided to buy myself a new soldering iron. I read reviews of the Hakko 888 throughout the year and I decided that if I found one at the Hamvention I would buy it! I was pleasantly suprised to discover that B&D Enterprises had Hakko soldering equipment for sale. Without hesitation I plopped down $105 and walked away with a Hakko FX888 soldering iron and five extra soldering iron tips.

This soldering iron replaced my old faithful Weller WES51 soldering station. I like the Hakko FX888 even better and I look forward to using it for many years to come.

Saturday, April 7, 2012

The Improved Neophyte Receiver: Part 2

I searched my archives for a suitable S-Meter circuit and it turns out that I had one in my Project Box. I have a Project Box that I keep kits in for future needs. One of the kits that I had was the Kanga Products "Audio 'S' Meter." The box was down in my basement and I had completely forgotten about it.

According to Kanga Products,
"Most homebrew receivers and transceivers lack any form of 'S' meter. They are not difficult to build but finding a suitable circuit that works is often a problem. This circuit is based loosely upon one from Doug DeMaw W1FB. The circuit samples the audio of the receiver after the detector, but before the audio volume control. The signal is amplified and rectified to give a DC voltage that varies according to the level of audio."

The enclosure style I have chosen for my receiver is to allow me to easily modify my circuitry until I have locked down my choices for performance and usability. I simply used a block of wood and a piece of artist board that has clay in it to build the reciever chassis. As you can see from the front of my receiver the design is constantly evolving. Do you see the 4 holes in a rectangle shape? I was going to mount the S-Meter circuit there but the spacing was a little too tight and it was interfering with the main tuning capacitor. So I decided to mount the main receiver board vertically and then attach the S-Meter board to one corner of the receiver board.

The next modification I want to make to my 40 Meter receiver is to add a digital frequency dial.


Saturday, February 18, 2012

The Improved Neophyte Receiver

Last year I decided to research a good receiver circuit for the 40 Meter band. I kept coming back to "The Improved Neophyte Receiver." The original Neophyte Receiver appeared in the February 1988 issue of QST on page 14 and written by John Dillon, WA3RNC. Over three years ago I bought a kit of parts for the "Improved Neophyte Receiver" from Dan's Small Parts. The article "Improved Neophyte Receiver" was written by Wes Baden, K6EIL. I ordered the circuit board from FAR Circuits. The partially built reciever board stayed incomplete in my junk box for a long time. I decided now was the time to finish it! I completed my build on January 29, 2012.

The first thing that I noticed was that I had my RF gain and Audio gain controls wired backwards. After I fixed that I noticed that the receiver had a real bad drift problem. I immediately asked for some help finding some new capacitors on the QRP-L mail list. Steve Smith, WB6TNL  came to my rescue with some nice NP0 capacitors for C2, C4, C5, C6, and C8. C8 evidently was the worst offender because as soon as I replaced that capacitor the frequency drift improved immediately! Before I replaced C8, the radio was just about useless. Now I can go make a cup of coffee and the radio is still on frequency when I get back to the shack. :)

Now I want to add some modifications to this receiver: a S-meter and a digital display. I will update my blog when those modications are complete.

Friday, August 19, 2011

Using Cookie Tins for QRP Projects

Today I received a cookie tin filled with brownies from a friend of mine at work. As soon as I saw the container I immediately said to myself that "it would work great for a QRP project!" So here is a picture of the cookie tin. I am looking for a way to remove the paint from the tin box.