Products > Test Equipment
FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator
GregDunn:
That would be interesting, thanks! There are some online filter calculators which work nicely; I've used a couple of them to design both active and passive crossovers for my stereo.
For what I'm doing, .03% is perfectly fine - I'm just using it as a quick performance check on amplifiers when I'm setting bias; and none of the amps requires an input voltage of more than 1.5V for full output, so attenuator losses could be pretty severe and not hurt the measurements. But ultimately I'll need a separate box because all I did here was run directly into the HP331A and it has a full range attenuator on its input already.
soundtec:
Thanks for testing the theory Greg ,my suspicions were correct ,
.03%, thats impressive , As you suggest thats an equivalent figure for a 12 bit system. Maybe distortion in the 3002 op amp is the limit your seeing at 20 volts swing ,are you running standard parts,voltages in your unit ?If it is, my guess is the 3491's distortion should be an order of magnitude lower than what were seeing now and maybe the full 14 bit resolution is just achievable .
With the use of the afore mentioned attenuator ,mods and maybe JS's filtering idea its seems likely the 66/6800 could generate very high quality audio waveforms ,good enough for distortion measurements in other equipments . Its kind of interesting in that we spent a good deal of time thinking about ways of improving the signal quality in the digital domain ,in fact the answer was make best use of the bits we have .I wonder with a filter to supress the harmonics could we exceed the theoretical limits of the 14 bit convertors .
GregDunn:
Yes, though that's at full output, 10 KHz only, it's a completely standard unit as far as I'm aware. Latest firmware.
Keep in mind that I don't have a super-quiet bench and that 331A is only spec'ed to a residual THD+N of 70 dB at audio frequencies, so I'm likely just measuring the meter's residuals here. That's why super-low distortion is not a big concern to me at this time. Now maybe when I find that minty Sound Technology 1700B at a hamfest... :-DD
bdivi:
--- Quote from: danco on August 18, 2018, 03:14:32 pm ---Where did you buy in BG with free shipping, my suplyer of choice (TME) doesn't seem to stock it?
--- End quote ---
Direct order to TI - store.ti.com
danco:
Thank you, I'll try it myself.
--- Quote from: bdivi on August 21, 2018, 06:08:45 pm ---
--- Quote from: danco on August 18, 2018, 03:14:32 pm ---Where did you buy in BG with free shipping, my suplyer of choice (TME) doesn't seem to stock it?
--- End quote ---
Direct order to TI - store.ti.com
--- End quote ---
Sent from my MI 5s Plus using Tapatalk
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version