Updated album Mystery 330MHz signal on top of a 3mA pulse from a P6302 - AM503B Combination #photo-notice


TekScopes@groups.io Notification <noreply@...>
 

Dennis Tillman W7pF <dennis@...> updated the album Mystery 330MHz signal on top of a 3mA pulse from a P6302 - AM503B Combination: Can anyone explain the origin of this 330MHz signal and why it is not present before the rising edge of the pulse. Photos proceed from right to left due to the way Groups.io uploads them then prevents you from reordering them. That is really dumb and I will suggest they provide us with a way to place the photos in the order we want them to appear. Dennis Tillman W7pF 5/23/2021


Ed (SCSKITS)
 

Dennis:

Have you tried this with a pulse that has a slower rising edge, such as the square wave or pulse out of a function generator?

Does it do the same thing with a falling edge pulse, no 150MHz before followed by 150MHz during and after.

How long does the 150MHz ringing last?

ed


 

Hi Ed,

Thanks for the suggestions.
I haven't tried it with slower pulses of square waves. That might give me a clue to the origin of this signal. When I get a chance I will give this a try.

"Ringing" may have been a poor choice of words by me. Ringing implies a decaying amplitude. There was no sign this was decaying. Its amplitude was constant for the length of the trace in the photos I took. I did not try longer sweep times. My impression was it was going to last quite a while. There were a few things that puzzled me about this like how could it be there on the trailing edge of the pulse and not be there at the leading edge.

There could be a lot of innocent explanations for the noise and what I saw. I try to be very careful when I see things like this to be sure I haven't done something stupid. But it could just be some pickup in a coax cable, or a dozen other possibilities I can think of, that has gone bad since the last time I tested it on a TDR.

Dennis

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Ed (SCSKITS)
Sent: Monday, May 24, 2021 2:53 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Updated album Mystery 330MHz signal on top of a 3mA pulse from a P6302 - AM503B Combination #photo-notice

Dennis:

Have you tried this with a pulse that has a slower rising edge, such as the square wave or pulse out of a function generator?

Does it do the same thing with a falling edge pulse, no 150MHz before followed by 150MHz during and after.

How long does the 150MHz ringing last?

ed







--
Dennis Tillman W7pF
TekScopes Moderator