DIY Test Equipment

[psychedelicfish]

A quick search revealed nothing, so I thought I'd start a thread for DIY test equipment pics!

I'll start with my recently completed XR2206 based Function Generator:


Back:


Guts:


Waves:


Labelled Picture of the front panel:


What Test Equipment have you guys made?

[duck_arse]

I've got an xr2206 based audio sweeper. somewhat modified. looks like you might have room on the board, psych ......

[apollomusicservice]

Audio impedance meter
I made this impedance meter for quick measure impedance of pedal effects, output trafos etc.
Details and schematics published on http://www.freestompboxes.org/viewtopic.php?f=46&t=21829

[psychedelicfish]

I've got an xr2206 based audio sweeper. somewhat modified. looks like you might have room on the board, psych ......

I was thinking of using another XR2206 to generate sawtooth waves, which I could plug in to the FM input of my Function Generator and the sweep input of my oscilloscope and look at the frequency response of various circuits. While I may have room on the board, I don't really have room on either of the panels, so I'd have to build it in a separate box.

Audio impedance meter
I made this impedance meter for quick measure impedance of pedal effects, output trafos etc.
Details and schematics published on http://www.....org/viewtopic.php?f=46&t=21829

Looks pretty cool, useful too. I may have to make myself one sometime

[duck_arse]

my sweeper uses a 4060 (?) and resistor ladder for the ramp. I was looking in recently, to see how I could make it a fixed/variable output, instead of sweeping to a freq. dead easy, and I've got an unused pot on the front panel. one day, when it's warmer.

the impedance box looks nice, at the dreaded ellipses.org.

[Calambres]

Function generator based upon the NUXIE design:







More info (in spanish) here:

http://www.pisotones.com/GF/GF.htm

[monksanto]

Audio impedance meter
I made this impedance meter for quick measure impedance of pedal effects, output trafos etc.
Details and schematics published on http://www.....org/viewtopic.php?f=46&t=21829

Where is that schematic link..? I am interested in this. Thanks!

[apollomusicservice]

Here's the schematic.

More infos on my FB page.

[alanp]

If you've got a modular synth (it's fun to build ), it's worth building Cat Girl Synth's CGS60V1 module. That way, you can use VCO's as an oscillation source, you can chop 'em up into a trem with a VCA/LFO, imagination is the limit

[tca]

I've always wanted to transform an old CRT TV into an BIG oscilloscope. Any tries?

Cheers.

[psychedelicfish]

I've always wanted to transform an old CRT TV into an BIG oscilloscope. Any tries?

Cheers.

It's possible, but it sounds dangerous, difficult, and ultimately unsatisfactory. An oscilloscope is a measuring instrument, so a hacked together sweep generator and any old vertical amplifier would give you some fairly sub par results. IMO it wouldn't be worth the effort or risk to make something even close to being satisfactory.

[amptramp]

I've always wanted to transform an old CRT TV into an BIG oscilloscope. Any tries?

Cheers.

I have seen it done with a vertical trace for the time base and horizontal for the amplitude.  The input signal is sent through a variable delay that varies with the input on the horizontal signal.  The delay feeds a spike into the video so you get a raster-based oscilloscope.

[Calambres]

Audio impedance meter
I made this impedance meter for quick measure impedance of pedal effects, output trafos etc.
Details and schematics published on http://www.....org/viewtopic.php?f=46&t=21829

The link is broken...

[Lurco]

http://www.dos4ever.com/uscope/uscope_e.html

[apollomusicservice]

Audio impedance meter
I made this impedance meter for quick measure impedance of pedal effects, output trafos etc.
Details and schematics published on http://www.....org/viewtopic.php?f=46&t=21829

The link is broken...

Procedure for measuring.

[Calambres]

Thanks!

[free electron]

Here is a few of mine:

1. 10 - 100kHz DDS signal generator, 3 waveforms, sweep mode. Project developed on Polish tube enthusiasts forum trioda.com. I designed the PCBs




2. Not really DIY, but i hacked it. Component tester (http://www.mikrocontroller.net/articles/AVR_Transistortester), Chinese clone for about 20€ from *bay. I added the stand offs, battery holder and the ISP header to be able to upgrade the firmware to the most recent one. Amazing piece of gear for the money! Kudos for the guys who developed it:




3. This one is still in the develop phase: small V/I/P meter with alarm function (beeps if the current consumption is above the set threshold). What is done for now:

• 0.96" I2C OLED display
• Nokia5110 type SPI LCD
• the measurements are sent to the PC via UART (USB bridge)
• UART output us updated in controlled rate, can be used for data logging, doing long term measurements etc.
• the data is sent in two formats: LCD, copy of the LCD layout (picture below) or RAW, just the values separated with semicolons - ready to use with calc/excel
• based on PIC24 + INA219, range: 1A, 26V max

To do:

• calibration mode via UART
• implementing more control commands
• making it open source/harware

[therecordingart]

If any of you are willing to create a PCB layout for this in Eagle then I'm willing to mill you a few boards in exchange. I'm getting my feet wet with PCB milling, but suck at PCB layout. Alternatively, I'll etch the boards as well, but would rather take the opportunity to play with my CNC.

Here's the schematic.

More infos on my FB page.

[apollomusicservice]

This is PCB.

[duck_arse]

the worse for wear, but MUCH [?] the better for mods, here is my now modded xr2206 sweep/spot generator.




made from a kit, published in electronics australia. dunno what the bloke designed the board was thinking, it is a right mess, wires everywhere, possible easy mods made v. difficult, etc. and my mods haven't improved the insides, either, and have included a bug. I took out the microphone amplifier and meter, never once used them, hence the burns blanking plate.

@psych - can you show or link to your circuit, my triangle has square tops.