Hi A little quick clarification for those who don’t spend a lot of time studying PC board electro-magnetics:
Reference conductor = that thing you labeled ground on the pc board. Ground = when you trip while walking the dog, it’s the thing you hit ( = earth) No that’s not the complete story, but it’s enough to get you going. ===== Think of what happens to a box with big leads on either side of it. Consider equal length cables. Looks a lot like a dipole with a connection in the center doesn’t it? That’s exactly what happens in some situations. The cables pick up the RF and max current hits right in the middle … === Hope that helps. Bob > On Oct 12, 2015, at 4:25 PM, Chris Caudle <ch...@chriscaudle.org> wrote: > > On Mon, October 12, 2015 9:08 am, Chris Wilson wrote: >> I have found when the TX is on at 136kHz the Trimble / divider >> baord output goes wild and a clean square wave goes seemingly random >> on my scope with noise. > > How are your input and output cables physically configured? I noticed on > the link that Dave just posted that he uses a divider board inside a > conductive enclosure, and the input connectors are fed from short coax > cables which have their shields all connected to the same metal panel of > the enclosure. > The printed circuit board has input and outputs on opposite ends of the > board, and the connector shells appear to be connected to the circuit > reference conductor, which means that if the input and output cable > shields are not close together and connected together electrically very > well, all the shield current will be forced to flow across the printed > circuit board reference conductor. Perhaps with your transmitter > operating so closely it is resulting in a lot of ground bounce at the > various components on the divider board. > As you say, connecting the 10MHz directly without the divider in place > would help confirm or eliminate that possibility. > > -- > Chris Caudle > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.