STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM

[PaulLowrance]

I did a little more research on this and it doesn't look like a good idea after all.  Sound card inputs are AC and can't measure DC like you said.  The frequency thing is an issue also.  Looks like eBay is my only option.  Thanks for your input.

GB

No problem GB. I've been through that hassle as well when I needed a lot of channels to only discover PC after PC after PC did not do DC. I even tried to find the darn capacitor and short it, lol, but it seems to be embedded within the audio chip circuitry, at least on my PC's.

Hey, I've seen old scopes on ebay for $20 before. Oldies, but a zillion times better than an audio AC probe.  And those old scopes do DC. 

[PaulLowrance]

Check these out. I have no idea if they work, and can only say what the ebay ad says,

$18. Bell & Howell Oscilloscope model 34. used dusty Bell and Howell model 34 Oscilloscope unit works no other acc. come with unit thank you for viewing my auction buyer pays shipping I accept all forms of payment thank you

http://cgi.ebay.com/Bell-Howell-Oscilloscope-model-34_W0QQitemZ140374201069QQcmdZViewItemQQptZBI_Oscilloscopes?hash=item20aef452ed


I would be very cautious of this one since the seller has not tested it.

$24.99, BBC M6003 Oscilloscope 60 MHz #5081.

http://cgi.ebay.com/BBC-M6003-Oscilloscope-60-MHz-5081_W0QQitemZ320468256089QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4a9d658559


There are plenty more on ebay.

[lumen]

I did a little more research on this and it doesn't look like a good idea after all.  Sound card inputs are AC and can't measure DC like you said.  The frequency thing is an issue also.  Looks like eBay is my only option.  Thanks for your input.

GB

I already have two analog quad channel scopes, (100Mhz and 60Mhz) but was looking at those USB scopes on Ebay just for the digital storage ability.
Some of them look very good but I also wonder about the input attenuation.
They seem to be reasonably inexpensive for what they can do.

[k4zep]

Hi Gang,

Just messing around.

See:  http://www.youtube.com/watch?v=Dd66AQLCdeI

Slow and quiet, Yahama turntable gave up its life for me, found at a a Yard Sale, Stripped down turntable, etc.  Guts all gone inside only wanted platter and bearing.  Clean bearing, re-lubed with good oil. Spin down is about 6 min from a good hand spin so very free. Added plastic platter on top to get more mass to the rotor.  Will get exact inductance, resistance, shunt resistance, etc. if any one interested.  Still running on 650 F BoostCap, starting voltage 2.000 after 35 min. with .670V drop on cap.  Wanting to see if in the spin down there is a sweet spot.  It is VERY close, much more over time, I'm the worlds slowest builder. When I'm done, will look sort of neat, plastic cover and all that!  Think too much.

Ben

[lumen]

Hi Gang,

Just messing around.

See:  http://www.youtube.com/watch?v=Dd66AQLCdeI

Slow and quiet, Yahama turntable gave up its life for me, found at a a Yard Sale, Stripped down turntable, etc.  Guts all gone inside only wanted platter and bearing.  Clean bearing, re-lubed with good oil. Spin down is about 6 min from a good hand spin so very free. Added plastic platter on top to get more mass to the rotor.  Will get exact inductance, resistance, shunt resistance, etc. if any one interested.  Still running on 650 F BoostCap, starting voltage 2.000 after 35 min. with .670V drop on cap.  Wanting to see if in the spin down there is a sweet spot.  It is VERY close, much more over time, I'm the worlds slowest builder. When I'm done, will look sort of neat, plastic cover and all that!  Think too much.

Ben

@k4zep

It looks good to me! I like the cap for the supply, it shows real world draw that is easily calculated. It should work out well once your finished and add a charger circuit.
Your also not the slowest builder, I haven't even started, and I have CNC machines in the shed!