In Reply to: Hee hee..we're jumpin thread to thread.. posted by jneutron on August 22, 2003 at 10:28:00:
I did go back and look at the threads you referenced, and I saw lots of miscommunication in all directions.... Pity, given the potential value of real communication.Somehow John and SE got into this bizarre thread concerning gain of a mac sound card, which as far as I know has nothing to do with the test...
So, here's what I saw at JC's:
Sound Tech 1700B (modified) acting as oscillator. Signal fed into cable under test. Output of cable goes into 1700B to null out the fundamental. Residual output of 1700B (minus the fundamental) sent to two spectrum analyzers. One is an old HP3580, the other is (from memory) an HP3563. The main difference is that the 3563 completes a measurement in much less time. The results were plainly visible on both scopes. The 3580 showed almost as much detail as the 3563. It just takes longer to do the measurements. The 3580 has a dynamic range of about 80dB, but of course we were starting way below the amplitude of the fundamental since we were looking at the distortion residuals.
I just bought a used 3580 on eBay for $300; don't know its condition yet... I'm not that concerned about its absolute calibration state, since my primary interest is in looking at the shape of the distortion spectra of equipment I build, rather than the exact magnitudes.
Peter
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Follow Ups
- So maybe I can help the communication - Commuteman 11:20:15 08/22/03 (41)
- Re: So maybe I can help the communication - john curl 15:30:28 08/22/03 (40)
- Seebeck/peltier... - jneutron 19:24:11 08/22/03 (36)
- Re: Seebeck/peltier... - john curl 23:21:43 08/22/03 (35)
- Re: Seebeck/peltier... - jneutron 04:53:47 08/23/03 (34)
- Re: Seebeck/peltier... - john curl 08:22:30 08/23/03 (33)
- Re: Seebeck/peltier... - jneutron 09:01:31 08/23/03 (32)
- Re: Seebeck/peltier... - john curl 09:54:43 08/23/03 (31)
- Ah...deflection of any technical conversation..typical, John - jneutron 10:22:54 08/23/03 (30)
- Re: Ah...deflection of any technical conversation..typical, John - john curl 13:06:57 08/23/03 (29)
- Re: Ah...deflection of any technical conversation..typical, John - jneutron 16:29:53 08/23/03 (28)
- Ok, so can you explain how these thermal effects might manifest themselves? - Commuteman 17:29:51 08/23/03 (27)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - jneutron 12:54:34 08/24/03 (26)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - john curl 15:37:42 08/24/03 (25)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - jneutron 07:59:53 08/25/03 (24)
- Can you stop arguing with JC and describe what you think might be happening? - Commuteman 09:09:25 08/25/03 (8)
- Who's arguing? I'm being bashed for trying to explain. - jneutron 11:21:13 08/25/03 (7)
- Are you sure you can use this Seebeck/Peltier cause and effect model? - Commuteman 12:18:56 08/25/03 (6)
- I forgot to add.. - jneutron 17:20:41 08/25/03 (0)
- I'll stick to this thread. - jneutron 12:31:19 08/25/03 (4)
- Can we get to some ballpark numbers to see if it's significant? - Commuteman 13:41:47 08/25/03 (3)
- You're killin me... - jneutron 15:56:18 08/25/03 (2)
- I think we're using the same numbers.. - Commuteman 17:28:12 08/25/03 (1)
- AHA!!!!! So that's where the error is... - jneutron 17:46:53 08/25/03 (0)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - john curl 08:50:17 08/25/03 (14)
- JC..you really have to read the posts.... - jneutron 10:29:16 08/25/03 (13)
- Re: JC..you really have to read the posts.... - john curl 13:36:44 08/25/03 (10)
- Hi John - jneutron 15:21:15 08/25/03 (9)
- Re: Hi John - john curl 16:47:15 08/25/03 (8)
- Re: Hi John - jneutron 17:04:43 08/25/03 (7)
- Re: Hi John - john curl 20:16:24 08/25/03 (6)
- Re: Hi John - jneutron 21:34:29 08/25/03 (5)
- And BTW..You never did say who Dr. Van den Hul was.. - jneutron 21:48:10 08/25/03 (4)
- Everyone is entitled to their opinion.... - Charles Hansen 22:03:03 08/25/03 (3)
- Hmmm. - jneutron 05:41:31 08/26/03 (0)
- Hellllooo Charles... - jneutron 03:45:13 08/26/03 (1)
- OH, and Charles..... - jneutron 04:55:27 08/26/03 (0)
- Peltier effects are reversible with current direction - Commuteman 11:43:41 08/25/03 (1)
- AHA..gotcha - jneutron 11:58:44 08/25/03 (0)
- Yep, my oscillator is now the problem - Commuteman 16:31:13 08/22/03 (2)
- Re: Yep, my oscillator is now the problem - Dan Banquer 05:29:28 08/23/03 (1)
- Thanks - Commuteman 09:59:43 08/23/03 (0)