Re: Tracing receive signal for low signal
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Bob Lunsford <nocrud222@...>
Use the 10K probe and take the onscreen o'scope readings and
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compensate with the readings using a factor of 10... You can then use the scope's vertical amplifier to bring the reading up to a viable trace/reading and using the scale see what you have. The "10X" probe means it is ten times less likely to load the circuit being read which is what you really want. Some 'scopes also have an instantaneous digital reading but those tend to be relatively expensive. The secret is to take readings with the same techniques at all points and do the math to interpret the readings. Then you can come up with useful data. Bob — KK5R --------------------------------------------
On Sat, 1/12/19, Dave Space <davesspacebar@...> wrote:
Subject: Re: [BITX20] Tracing receive signal for low signal To: BITX20@groups.io Date: Saturday, January 12, 2019, 11:17 AM Thanks for all the info. Ok trying to see if I got this. It does look like loading. 1x probe is 1.2k 10x probe is 8.9 Mohms I checked the probe directly outputting 50mv verified 50mv through a .01uF blocking cap @ 11.996MHZ I put the generator into tp17 and measured at tp17 and I would say less than 5mv p-p was being read from what I could tell. I wasn't understanding if there is a way to now match this better or not? Thanks
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