Fun with Oscilloscopes Parts I, II, III

1. A simple demo: http://www.youtube.com/watch?v=xS0HwHlEzRM&feature=related

... uses a signal generator and some music ...

2. A Scope Clock: http://www.youtube.com/watch?v=o1cRNSNhEAM&feature=related

... these clocks typically use vector graphics in which the objects are draw individually, not painted top to bottom, left to right like in a television set. Remember the famous Asteroids video game ? http://www.youtube.com/watch?v=SBYy81hKQjc

3. And to top it off, Tetris ! http://www.youtube.com/watch?v=Hui5Azx5jQo

Is anybody interested in small computers ? Oscilloscopes ? I've got some displays if someone wants to try a scope clock !

73
Scott
KD5NJR

NW5W High Altitude Balloon Project

NW5W High Altitude Balloon Project

Some info here on hacking Cannon brand cameras
*to add features, some electronics,
*some ham radio, but what impressed me the most was
*this cheap little Arduino microcontroller.

... more to follow.

73
Scott
KD5NJR

Interesting Article on Checking Out An Old Radio

http://frrl.wordpress.com/2008/12/29/hands-on-electronics-signal-tracing-a-simple-transmitter/

Hands-on Electronics - Signal tracing a simple transmitter
Or, How not to be an appliance operator

Is ham radio still about electronics? If you think so, then this posting is for you.

You may want to read our nearly related article on the Heathkit radios (Collecting Heathkit Models SB-101,102 & HW 100,101 ). That posting contains a high level conceptual explanation of how the transmit section of those radios work. We think that the Heathkit folks missed an opportunity in the education market.

Heathkit had a great platform in the SB and HW series of transceivers to serve as a course in electronics - learn as you build. But that was not to be. Perhaps an objection is that there were high voltages in the Heathkits - 800 volts on the plates of the tubes. So, sticking fingers in the wrong place in a Heathkit is going to get you zapped. So maybe that would undermine ones joy of learning.

Recent Soldersmoke Posts

http://soldersmoke.blogspot.com/
* WebSDR Receiver Goes to Six Bands
* ARRL Straight Key Night
* ECHO Satellite Beacon

I think I'm going to like the Echo Satellite information.

If you're new to the whole Soldersmoke thing, you can pick out some podcast files (don't worry, they're just MP3s) here: http://www.soldersmoke.com/

73
Scott
KD5NJR

Affiliations

Want more blogspots to eyeball? Check out the following -

Broken Arrow Ham Radio Breakfast - ke5lep.blogspot.com

Broken Arrow Amateur Radio Club - w5bbs.blogspot.com

Tech Net Notes December 17, 2008

1. ke5omv, Don asks, "How do I splice two pieces of coax together? Should I use 2 PL259s and a coupler, or something else?”

Kd5cny, Tom says, “Barrel connector, “N” connector is a little better but harder to put on. I would suggest a PL 259, a little more loss, but probably not enough that you would notice.

Ke5lnn, Dave, “Purist would advise you not to splice together like that because of the loss.” Tom says, “1/10th of a db loss on each connector”. Ray says, “Put waterproof tape around the connector. I had a little higher SWR when I used a splice with a barrel connectors.

Kd5cny, Tom asks, “At what frequencies will you be running through the coax?” Answer: “70 cm & 2-meter”. Tom says, “If running 440 I strongly suggest not using three pieces of cable”.


2. ke5lnn, Dave asks, "When I have my mobile radio on scan mode and engage my automobile cruise control, the radio scan is interrupted. How do I fix it?"

Ke5lnn adds, Dave says that ferrite RF chokes have not helped any. He thinks he may have to do something with the cruise control. The hot line goes to the battery. Ground goes to the chassis.

From another ham: The cruise control module is located either under the dash or under the hood. If you run your wiring anywhere close to the cruise control module, you may be picking up interference. You may want to try rewiring the power along a different route. You might try moving your ground and your power cord to a different location.

Jeff asks, “What does the cruise control module look like?” Ray, kc5wsi, “What is the year and Make of the vehicle?” If it’s a Chrysler product, they have been known to have cruise control units that affect other vehicle electronics. Dave says, “It’s a 2001 Toyota Tacoma.” Ray says, “The unit is probably going to be under the dash with four to 5 wires 1” x 3” x 5”. It should have a back plug on one end. I will try to find out specifically what it looks like and its location and get back with you next week.”

Kc5bgf, David says, “You might try a coax line for your power feed line. Older coax is often heavier and some is double shielded and makes a better conductor.”

Kd5cny, Tom, “Fuel pump noise in today’s cars is often a problem for interference.”

Tech Net Notes December 5, 2008

Editors Note: I know I'm not getting a lot of the answers right, so if you answerred and see that I did not get what you were saying, please leave a comment and I will correct the answer on the post.


1. kd5njr, Scott asks, "When exactly are you supposed to use a balun?"

ae5hq, "On ladder line feeding a dipole, you don't need a balun because it is balanced. On coax line feeding a dipole, you need a balun"

ww5wow, 300 to 1000 ohm use 4:1, you can use 6 turns of coax as a balance. On a wire fed antenna you need to bring a 300 or 450 ohm antenna down to 50 ohm, it is then that a 4:1 balun will be needed. Otherwise to make the transition from ladder line to coax a 1:1 balun will need to be used.

k5zdp, 4:1 is used to change the characteristics of the antenna to keep the signal off the shield.

kd5zve, Jimmy says, "Antenna modeling software is found by googling eznec and learning more about baluns.

2. ke5lep, Stan asks, "How do I get my Kenwood MC-57DM microphone to work in DTMF mode with my Kewood TS-2000 radio?"




3. ke5lnn, Dave asks, "When I have my mobile radio on scan mode and engage my automobile cruise control, the radio scan is interrupted. How do I fix it?"



4. w5amr, John asks, "APRS, on the receive side, I have never been able to get any of the software to show me a map of the location of the transmitters."

ww5wow, Larry - If you don't have a program to receive RF signals, you're not going to get anything from them.

ke5lep, Stan , "I can't contribute to your answer, but leave it as a comment and maybe we can get an answer." I am looking at www.openaprs.net, a website that has software that shows the radios by zipcode.

Software found by googling eznec

ae5jc, Bob says, "Try winaprs, www.winaprs.com, links to maps that can be downloaded for that."

Congratulations! Tulsa Tech Net

Yesterday, December 5 marked the beginning of something good. The Tulsa Tech Net started with a large group of amateurs from 4 or 5 of the local clubs. Broken Arrow Amateur Radio Club hosted the event on the 146.910 repeater. Don Roberts(KE5OMV), Dan Lairmore(W5YDL) and Ray Truitt(KC5WSI) were the Net Control operators and set the direction of the event. All of the stations were encouraged to ID, give their first name, and start discussion on any topic that would be helpful to them and the group.

The topics that come to mind were:

Baluns - When do you use them? What is their purpose? Are the needed at all? What about the type to use (4:1 - 1:1).

APRS - Where can you find a site on the WWW (Internet) that shows the location and map of APRS equipped mobile riggs.

Other Radio Specific Questions - How do you use a DTMF mic on a Kenwood TS-2000 Radio.
What could cause a radio to stop scanning when the vehicle cruise control is activated.

Many things that will be recorded on the Tulsa Tech Net Blog were discussed.

If you have any unresolved attemts to communicate feel free to Email me at stanpennington@valornet.com I will forward messages to Don, Dan and Ray.

This was a great start to a worthwhile project.