In Reply to: RE: update 2 posted by vinnie2 on February 19, 2019 at 04:58:32:
"Then what exactly did you mean by the voltage I should be measuring is AC not DC? That would imply that either could be measured. Please add a little clarification."What I mean is that you cannot be getting a steady DC voltage from the output transformer secondary. You must have been seeing an AC voltage on your scope. And indeed, you then confirmed that when you had said 48vdc, you had meant to say 48v peak-to-peak AC voltage. Which would be fine, except that 48v peak-to-peak is way too high to be getting from that single-ended amplifier you have breadboarded. So something must be amiss with your measurement.
I am just suggesting that you try playing around with measuring the RMS output voltage from your signal generator using a dvm, and then comparing it with the peak-to-peak voltage that you can easily read off from the scope. The two should be related as I said before. If they are not, then it would provide concrete evidence that something has gone astray with your interpretation of the peak-to-peak reading from the scope. (Or that something is wrong with the scope.)
There isn't really an issue of "setting the scope to measure AC or DC." It is just showing a trace of the waveform you feed into it. And you are feeding in an AC waveform from the output transformer. (It is true one can usually set an AC or DC input coupling on the scope, but that is not relevant here, since your signal you are feeding it will be pure AC, with no superimposed DC.)
But since the peak-to-peak voltage you are reporting from the amplifier seems to be implausibly high, the obvious first thing to try would be testing things out on a convenient AC voltage such as from the signal generator itself, and comparing with the RMS voltage measured with the dvm.
Edits: 02/19/19
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Follow Ups
- RE: update 2 - cpotl 05:40:56 02/19/19 (32)
- RE: update 2 - vinnie2 07:00:18 02/19/19 (31)
- RE: update 2 - deafbykhorns 15:15:55 02/20/19 (30)
- RE: update 2 - Tre' 10:12:50 02/22/19 (0)
- much better! - vinnie2 06:21:16 02/22/19 (24)
- RE: much better! - cpotl 08:42:38 02/22/19 (23)
- RE: Sample Sine Wave - deafbykhorns 11:28:41 02/22/19 (20)
- 845 op points - vinnie2 06:19:57 02/23/19 (0)
- RE: Sample Sine Wave - vinnie2 05:02:59 02/23/19 (15)
- RE: Sample Sine Wave - deafbykhorns 16:51:37 02/23/19 (14)
- RE: Sample Sine Wave - vinnie2 17:56:28 02/23/19 (13)
- RE: Grid Current - deafbykhorns 14:56:39 02/24/19 (7)
- RE: Grid Current - vinnie2 17:59:00 02/24/19 (6)
- RE: Grid Current - deafbykhorns 06:00:36 02/25/19 (5)
- RE: Grid Current - vinnie2 06:44:26 02/25/19 (4)
- RE: Try the 300B with a good DHT - deafbykhorns 07:54:02 02/25/19 (3)
- RE: Try the 300B with a good DHT - vinnie2 09:19:20 02/25/19 (2)
- RE: Try the 300B with a good DHT - deafbykhorns 13:01:02 02/25/19 (1)
- thanks! nt - vinnie2 13:59:12 02/25/19 (0)
- what are the 6sn7 op points? (nt) - Tre' 06:53:46 02/24/19 (4)
- RE: what are the 6sn7 op points? (nt) - vinnie2 14:45:14 02/24/19 (3)
- RE: what are the 6sn7 op points? (nt) - Tre' 18:02:17 02/25/19 (2)
- RE: what are the 6sn7 op points? (nt) - vinnie2 04:31:51 02/26/19 (1)
- RE: what are the 6sn7 op points? (nt) - cpotl 05:07:07 02/26/19 (0)
- good post (nt) - Tre' 14:06:08 02/22/19 (0)
- RE: Sample Sine Wave - vinnie2 11:40:25 02/22/19 (1)
- RE: Sample Sine Wave - Tre' 14:05:06 02/22/19 (0)
- Good point. - Tre' 10:43:36 02/22/19 (0)
- RE: much better! - vinnie2 09:56:27 02/22/19 (0)
- RE: update 2 - vinnie2 06:23:22 02/21/19 (2)
- RE: Example - deafbykhorns 12:38:17 02/21/19 (0)
- RE: update 2 - cpotl 08:29:18 02/21/19 (0)
- RE: update 2 - vinnie2 17:54:53 02/20/19 (0)