duncan crane

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About duncan crane

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  • Birthday 04/06/1947

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    Northampton, MA
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    radio science, sailing, family

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  1. 1. Here is my setup using the BNC adaptor and the external signal generator feeding channel 1 with nothing on channel 2. 2. Looking at WaveForms Scope I see 4 V p2p, at ~1 MHz on channel 1... 3. ... and due to crosstalk I see 50 mV p2p on channel 2. 4. Now I attach the short on channel 2 ... 5. And the crosstalk goes way down. 6. The testing with and without the short on channel 2 is informative and demonstrates well the existence of the crosstalk. But when I use the AD2 in my application I have signals coming in on channel 1 and 2 so of cours
  2. Thanks for the detailed response Atilla. I duplicated your tests to make sure I understood what you were saying and to verify my AD2 is working properly. Screen shots attached. I used an external signal generator for all my tests rather than the built-in signal generator in Wavegen. You did not get significant crosstalk using an external signal generator but I did. Shorting out the other channel helped a little when I was NOT using the BNC adaptor and it really helped a lot when I WAS using the adaptor. So our test results were similar. It is interesting to note that when feedin
  3. atilla, Sorry for the delay in response to your feedback. I have been out of action with the flu and in fact am still a little light headed. I think I understand what you are saying and have come up with a way to measure any random delay introduced by the two AD2 channels and subsequent Math Filtering. I have two 10 ft long straight wire antennas stretched across my living room ceiling, mounted with insulators at each end. (My wife just loves them. Not.) Using these two antennas as inputs to channels 1 and 2 on the AD2, I set the Math Filters on both to 560 KHz (near the low end
  4. I know I have a lot to learn about this device and plan to work through the conversations on the Forum and the many YouTube videos out there. Please point me to any especially informative sources that you think I would benefit from. You have got me thinking in a slightly different direction. I have been talking about "triggering" but maybe I don't need triggering in the classical sense. I like the way I can hit the Single button on the scope and capture a few cycles of my signals on the two channels. I don't need a repeating sweep, just one capture gives me what I need. And I don't c
  5. atilla, I purchased my AD2. Love it. Here is what I am seeing using your suggestion of a Math filter. This is a lovely picture of the 1.4 MHz carrier from my local AM broadcast station WHMP. However, the triggering is not right. Every time I do a Single capture I get this same picture but it crosses the 0 sec vertical at a different voltage. I am guessing that this is because the source of my trigger is Channel 1 which naturally contains all kinds of overlapping signals coming in from my antenna. So the Rising 0 volt point of Channel 1 will not necessarily line up with the
  6. Atilla, What you are showing with the Math Filter in WaveForms looks exactly like what I am looking for! Very exciting. Just to be clear, in your example the input comes in on one of the Analog Discovery 2 channels and is fed to a Math Filter routine in WaveForms. The output of the filter (in brown) is in the time domain and shows the original pre-sampled carrier wave form? So did the filter do a reverse FFT on the sampled spectrum? How precise can I get this picture? Can I see just a couple of cycles of the original AM carrier and be confident of where in time a given cycle sta
  7. I saw the Matlab option but have to admit I was scared off a little by all that I do not know. Maybe I should jump into it. Thanks X.
  8. I would like to use the Analog Discovery 2 to look at the carrier signal coming in from an AM broadcast station. To do this I would need to tune or filter the many signals coming in on my antenna down to one station of interest. I am thinking that this type of tuning is not something that the AD2 can do. Is this correct? Does anyone know of a simple device that can act as a front end to the AD2 to tune and perhaps amplify the signal in this way? I have looked into SDR's that are very focused on doing just this but I am not seeing how I can extract the carrier signal before it goes to mixi