[sdiy] What test gear do you use?

[sleepy_dog at gmx.de]

Ah, all that other gear. Since there was the question for budget stuff.

There are a lot of chinese budget signal generators even just for a few 
bucks.
For building synth stuff, I found that the *** 6600 devices are thos 
startting to get really useful, they have quite nice feature sets that 
you'd have to give an arm and a leg for if buying "proper" brands, but 
obviously, they have flaws, none of them is totally gread.
The *** could be JDS or FY, different makers of the same basic design, 
with different details.

this
https://www.ebay.com/itm/FeelTech-FY6600-15-60MHz-Function-Arbitrary-Waveform-Pulse-DDS-Signal-Generator/232430195900
has a proper DAC and an okay resolution, more memory points for 
arbitrary waveforms (still not a lot) than the thing below,
but the slight problem that their internal switching PSU capacitively 
leaks mains voltage to the BNC connector ground, not with much power 
behind it, but you need to earth it some way to not fry your circuits in 
some circumstance...

This one does not have this problem, but fewer memory, and a resistor 
DAC with maybe 11 bits realistic resolution vs. 14bit IC DAC.
https://www.ebay.com/itm/24-40MHz-JDS-6600-Dual-channel-DDS-Function-Waveform-Signal-Generator-Counter-LJ/112686417265

(this is all from memory & me looking at teardown forum threads, could 
be errors)

What can you do with it?
Say you build a VCF, and have no audio source to adjust well in a test 
scenario, you'd create one audio signal with one of the channels, and 
maybe activeave the sweep function for the other channel to sweep the 
VCF's cutoff frequency within a defined voltage range, to measure 
whether it behaves as expected.
(some things like sweeps are not a pleasure to set up with the front 
panel controls, but the PC (windows) software that comes with those is OK)

Using the arbitrary function part, you could program some special 
voltage movement to test certain behavior.

Then I have an even cheaper one of those which can do much less, for 2 
extra control voltage channels, but usability wise its even more spartan 
front panel is worse ;)

There are DDS generators for just a few bucks on ebay, without case 
(easy to fry accidentally) and often not a really useful analog 
frontend, e.g. you can't offset the voltage, or not by a lot, or can't 
adjust the amplitude (without sacrificing resolution), or not by a lot.
The two things linked above are quite usable in that regard (apart from 
falsely labeling  Vpp as "amplitude" in the menu)


- Steve


Am 06.05.2018 um 21:43 schrieb Michael E Caloroso:
> I do far more maintenance/repair/calibration than building circuits.
> My tools are:
>
> Tek 2430A
>
> ABI Chipmaster for testing logic ICs (not terribly comprehensive)
>
> Peak Electronics DCA75 for testing discrete components (nice tool)
>
> Tek 7904 comprehensive system consisting of these modules:
> 2x 7A26 vertical amplifiers
> 7B53A horizontal amplifier
> 7B92 horizontal amplifier
> 7D15 universal counter
> 7D01 logic analyzer w/ DF1 formatter
> 7L5 frequency analyzer
>
> One of the power features of this system is I can configure the logic
> analyzer to trigger on a microprocessor event, and then use THAT to
> trigger the analog scope system to capture an aperiodic signal.  Saved
> my butt a few times...
>
> Tek TM515 portable system consisting of:
> DC503 universal counter
> FG502 function generator
> SC503 storage analog scope
> DM501A DMM
>
> I also have a Tek FG504 function generator, but it won't plug into the
> TM515 chassis (not compatible).
>
> MC
>
> On 5/6/18, Jimmy Moore <jamoore84 at gmail.com> wrote:
>> I didn't mean to clutter up Quincas' thread with the scope conversation,
>> but I'd love to hear more about what test gear people use.
>>
>> I've recently gotten back into kit building, and Quincas' video on the kit
>> scope looked fun and useful -- Do people have other equipment that
>> similarly fills a similar purpose that is worth its while? Space is at a
>> premium in my apartment, which is why I'm interested in hearing about these
>> small kit things.  I don't have much room for a dedicated test bench!
>>
>> Steve's comment about the DSO112
>> <https://www.youtube.com/watch?v=fGU9LoEpQFw> brought me further down the
>> rabbit hole.
>>
>>
>>   What's everyone use?
>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at synth-diy.org
> http://synth-diy.org/mailman/listinfo/synth-diy
>