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G0HZU_JMR · 24th May 2021, 7:42 pm

At 1MHz I think the output of the triple RC network can be quickly simplified to something based on the final RC network. This means it will look like 1500R in parallel with about 1nF. This means you don't have to do any experiments to try and find the half voltage loading. It would be difficult to do this anyway because the source will be complex.

At 1MHz the series equivalent transformation will be about 16R in series with about -160R reactance and this is 16R in series with about 1nF at 1MHz.

It doesn't look to be a good circuit because it will be very lossy and the source impedance is a long way away from your target of 50R.

24th May 2021, 7:42 pm	#8
G0HZU_JMR Dekatron Join Date: Sep 2010 Location: Cheltenham, Gloucestershire, UK. Posts: 3,077	Re: 1MHz output impedance query? At 1MHz I think the output of the triple RC network can be quickly simplified to something based on the final RC network. This means it will look like 1500R in parallel with about 1nF. This means you don't have to do any experiments to try and find the half voltage loading. It would be difficult to do this anyway because the source will be complex. At 1MHz the series equivalent transformation will be about 16R in series with about -160R reactance and this is 16R in series with about 1nF at 1MHz. It doesn't look to be a good circuit because it will be very lossy and the source impedance is a long way away from your target of 50R. __________________ Regards, Jeremy G0HZU