KIX-OnlineLinks to amateur (ham) radio goodies on the web

Tektronix 465 O-Scope, commonly available online for a fair price

I know I’ve been tinkering around when I just spent a few hours looking at Oscope information!

I’ve been tinkering around a lot with QRP projects and some PIC based toys.  I’ve been wanting one on my bench for a few years now, but just couldn’t justify it – until now.

For past few years, more and more older analog scopes have been hitting the market in industrial surplus and on e-bay.  As companies are upgrading their equipment, many used scopes have been hitting the market for only a few hundred dollars.

I have found a bunch of decent videos and some good information on the Tektronix site.

First, I’m going to start of with a Wikipedia entry to give you some basic information.

An oscilloscope (commonly abbreviated to scope or O-scope) is a type of electronic test instrument that allows signal voltages to be viewed, usually as a two-dimensional graph of one or more electrical potential differences (vertical axis) plotted as a function of time or of some other voltage (horizontal axis). Although an oscilloscope displays voltage on its vertical axis, any other quantity that can be converted to a voltage can be displayed as well. In most instances, oscilloscopes show events that repeat with either no change, or change slowly. The oscilloscope is one of the most versatile and widely-used electronic instruments.

The rest of the information is available here: http://en.wikipedia.org/wiki/Oscilloscope This is one of the better writeups I’ve seen on Wikipedia.

Afrotechmods has a three part video set on YouTube that give a decent introduction to scopes with some really good advice as far as purchasing used on ebay and what is good for the home tech-bench.

AllAmericanFive radio has a neat intro to scopes.  He does a lot of videos on radio restoration and such.  VERY RECOMMENDED.

Found this neat older video here – still has good info.

Check out the Tektronix download here:  http://www.tek.com/learning/oscilloscopes/ You have to sign up to download from this site, but it is really worth it.  The sixty page booklet called “Oscilloscope Primer” is really worth reading.

There are a lot of sites out there with information on O-Scopes, this will get you started.

As usual, if you find any good links, please share with the rest of us and add a comment below.

**** late note/addition 4.24.09 ****

Based on a thread on the ‘zed, I have a few additions to add to the post.

The initial link from Tektronix (the one you have to register for) I think was for this file (direct download):

http://www.tek.com/Measurement/App_N…03W_8605_2.pdf

And here’s one that is a primer on probes:

http://www.tek.com/Measurement/App_N…60W_6053_9.pdf

Paul Harden, NA5N, has a few good, brief tutorials on his site:

http://www.aoc.nrao.edu/~pharden/hobby/Hobby.shtml

Here is his scope tutorial part 1:

http://www.aoc.nrao.edu/~pharden/hobby/Scope1.pdf

And here’s part 2:

http://www.aoc.nrao.edu/~pharden/hobby/Scope2.pdf

Quite possibly the cheapest scope?

I’m a sucker for a simple and useful project.  I teach ham radio license classes and this might just fit the bill for a simple scope to demonstrate basic principles.  Based on the Atmel Tiny45 CPU, this project can be easily built and with a low parts count.

Here is a little info from the designers website:

It has 2 analog inputs and can supply 5V ont the 4 pins header on the right. One of the inputs can be scaled down with the trim pot.
The firmware in the Tiny45 is written in C and compiled with Winavr and usb source code from obdev. As you can see, there is no crystal , the software sync the internal 16.5Mhz pll clock with the USB clock.
The cost with a home made pcb is around 5€.
Of course, do not expect 1Gs/s HID does not alow that data rate ! But it is using a 10bits AD.

This project can be put together in a very little amount of time and would be neat on a few fronts.  Many of us haven’t toyed around with Atmel products – this would be a simple and easy introduction.  Low parts count, so you get immediate project satisfaction.  The Atmel chip withstanding, we have many of these items in our junque box.

Software included on the project website.

The project site includes all the necessary source code and Eagle cad files, if you need them.

Simple parts list:

1 Led (any)
1 R for led, from 220 to 470 ohm, smaller is brighter
2 R 68 ohm on USB D+ & D-lines
1 Pull up R 1.5K for USB device detection
2 Zener 3.6V for right USB signal levels
2 Bypass caps 100nf & 47uf
2 filter caps on analog inputs ( from 10nf to 470nf or nothing, up to you)
1 or 2 trimpots on analog inputs to scale your voltage to AD range (1.2V or 2.5V by software )
1 USB socket (A,B, mini, you chose)
1 Atmel Tiny45-20.

The rest of the project creators site is French, which I have close to no knowledge of, so that part is up to you.  The project page is in English.

http://yveslebrac.blogspot.com/

I didn’t actually get to use one of these meters until the 2007 Dayton QRPARCI FDIM (Four Days In May).  After trying out two units, I don’t know how I got along without ‘em.

I have more experience with the Almost All Digital Electronics LC meter.

Almost All Digital Electronics L/C Meter II, Kit - $99.95

I used this when I built the SP-1 kit and borrowed one when I made parts for my BitX-20.  It is truly an indispensable took for the bench.  Especially working on projects where you are winding a lot of toroids and making other inductors.  That feature alone made it worthwhile for me.

That’s not all, from the AADE website:

L/C Meter IIB is a hand-held, digital Inductor inductance meter, Capacitor capacitance meter
with a four digit display,

It is ideal for RF and audio work where accurate measurement of small values is needed.
maximum resolution of 1 nHy / .01 pF
maximum range of 150 mHy / 1.5 uF.

Capacitors must be non-polorized as the test signal is AC.

The unit features
AUTOMATIC RANGING and SELF-CALIBRATION.

The L/C Meter IIB is available as a kit or fully assembled from Almost All Digital Electronics from their website at http://www.aade.com .

There is also a site with plenty of information on this kit, including how to use the meter.  Ian Purdie (VK2TIP) put together a list of his experiences with the kit and it’s many functions.  http://my.integritynet.com.au/purdic/lc-meter-project.htm

There is another similar product on the market that is worth mentioning.  Also at Dayton, I was able to look at the M3 Digital LCRZ meter.

M3 LCRZ Meter, kit starts at $175.00 and goes up depending on accessories

I have not built either of these kits (I’m hoping to get one in my budget soon).  I have used both meters.  The M3 is a truly neat project.

I met the guys at M3 at the FDIM program and was floored by the quality of this meter.  Not only the meter itself, but the cables as well.  M3 also has the option to purchase 4 wire Kelvin cables (really neat).  You can also purchase SMD cables as well – another neat option.

There are a couple more accessories available for the M3 meter a varactor diode test fixture and their multi test fixture.

According to the M3 website:

The M3 Digital LCRZ meter is a multi-frequency impedance measuring instrument capable of measuring resistance, capacitance, inductance or transformer parameters from 1 milliohm to 1 Megohm impedance. The LCRZ meter is controlled by a high speed micro controller with embedded logic that operates the display, keypad, as well as setting measurement conditions and performing calculations.

Measurement Modes (automatic or manual) and display ranges:

Inductance (L) + Q (quality)
L: 0.01uH to 99.99H   Q: 0.001 to 100

Inductance (L) + AL
L: 0.01uH to 99.99H   AL: L/N2 (N set by user from 1 to 999)

Capacitance (C) + D (dissipation)
C: 0.001pF to 99999uF   D: 0.001 to 10

Resistance (R) + Q
R: 1 milliOhm to 99.9 MegOhms   Q: 0.001 to 100

Absolute Impedance (|Z|) + Theta (Phase Angle)
|Z|: 1 milliohm to 99.9 MegOhms   Theta: -180 to +180 degrees

Resistance (R) + X (reactance)
R: 1 milliOhm to 99.9 MegOhms   X: 1 milliOhm to 99.99 MegOhms

Conductance (G) + B (Susceptance)

Transformers: Turns Ratio (N)+ Phase Angle, Power transformer Primary/Secondary voltages (Vp+Vs), and Mutual Inductance (M)

Varactor Diodes (with optional test fixture)

Automatic or manual selection of Equivalent Circuit Model (Series or Parallel).
Six automatic or manually selected impedance ranges.
Binning/Sorting by value or percentage
10 User selectable test frequencies: 100Hz, 120Hz, 250Hz, 500Hz, 1KHz, 2.5KHz, 5KHz, 7.8125KHz, 12.5KHz, 15.625KHz
Drive voltage = 0.5Vrms +/- 5%.
Measurement Rate = 2 measurements per second.
Basic Accuracy = 0.2%.
Open/Short zeroing.
4-wire connection to device under test.
Power requirement: 7.5VDC to 13VDC at 200mA

Information on the M3 LCRZ meter can be found on their website at http://www.m3electronix.com .

Bottom line, which one is for you?

Depends.

If you’re new to homebrew or QRP kit building, the AADE might be the kit for you.  It’s easier to build and will indeed fulfill many of those needs.

If you are an experienced builder and have a lot of kit building experience, the M3 might be for you.  It’s definitely a kit for a more experienced builder.  I looked at the contents and think it would indeed take an experienced builder a few nights to assemble.

But, as with all kit building, the final result is indeed rewarding.  Except instead of a transmitter or receiver, with these kits, you will have a valuable tool for your bench that will get plenty of use for years to come.