开云体育

On Monday, January 20, 2020, 10:38:13 AM PST, Bob Albert <bob91343@...> wrote:

Mike,
Thanks for the information.? I did not buy the device because I have a second nano that does okay.? But after reading your latest suggestion I guess I'll buy the thing and see if I can upgrade without bricking the unit.? It should also be a door to future upgrades.? Perhaps I can upgrade the second nano via its USB port but that unit is flaky and turns itself off without provocation.? It won't even turn on while the port is connected, and sometimes even when not connected it fails.? Once on, I can connect the port.? Then suddenly it behaves properly.
I did have thoughts of replacing the USB connector but it takes ability that I lack.? I think over a dozen tightly spaced pins and limited access and tools.
Bob

On Monday, January 20, 2020, 10:31:32 AM PST, Bob Albert via Groups.Io <bob91343@...> wrote:

Mike,
Thanks for the information.? I did not buy the device because I have a second nano that does okay.? But after reading your latest suggestion I guess I'll buy the thing and see if I can upgrade without bricking the unit.? It should also be a door to future upgrades.? Perhaps I can upgrade the second nano via its USB port but that unit is flaky and turns itself off without provocation.? It won't even turn on while the port is connected, and sometimes even when not connected it fails.? Once on, I can connect the port.? Then suddenly it behaves properly.
I did have thoughts of replacing the USB connector but it takes ability that I lack.? I think over a dozen tightly spaced pins and limited access and tools.
Bob
? ? On Monday, January 20, 2020, 10:13:05 AM PST, n2msqrp <mstangelo@...> wrote:

Bryan,

Thanks. I thought it had to do with the mismatch between the coax and S11 port. I had a length of RG-6 handy and see the same effect with that 75 ohm cable and see the same effect. Since the loss of the Rg-6 is higher the step responses is decreasing at a faster rate.

I have a 75 to 50 ohm pad. If I have time I may connect the pad to the S11 port, run a calibration using a 75 ohm load and run the test again.

Mike N2MS

Mike,

You need to think about what you are seeing in the time domain.? What the software produces is the impulse response (the positive going blips) and the step response (the steps in your plot) of the network attached.? The steps are the result of multiple trips of a wave traveling through your cable.? The part you are asking about is the step response of your cable.? Consider the following.