>>2. Several measurement techniques require a given phase relationship >>(e.g., quadrature) between DUT and reference. For HF frequencies (ie, 5 >>or 10 MHz) is there a *practical* phase shifter design covering 180+ >>degrees that doesn't involve switching various lengths of coax in and >>out of the line?
There was a Hewlett Packard generator called a two phase oscillator or maybe it was two phase function generator. I forget the model number and don't have any way to look it up. It featured two outputs and a dial calibrated from 0 to 359 that would adjust the phase of one output with respect to the other. Behind the panel was a little box which I didn't try to open but the manual revealed it to have 3 coils, two at right angles to each other and the third one on the shaft. It operated at 5 MHz. If memory serves correctly, they called it a variable phase transformer. Regards. Max. K 4 O D S. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com ----- Original Message ----- From: "Joe Gwinn" <joegw...@comcast.net> To: <time-nuts@febo.com> Sent: Wednesday, December 24, 2008 3:52 PM Subject: Re: [time-nuts] New topics (was Re: He is a Time-Nut Troublemaker....) > At 5:05 PM +0000 12/23/08, time-nuts-requ...@febo.com wrote: >>Date: Tue, 23 Dec 2008 11:40:51 -0500 >>From: John Ackermann N8UR <j...@febo.com> >>Subject: [time-nuts] New topics (was Re: He is a Time-Nut >> Troublemaker....) >>To: Discussion of precise time and frequency measurement >> <time-nuts@febo.com> >> >>Magnus Danielson wrote: >> >>> My intent is to get some stuff done in the lab during the vacation. >>> (Desperatly trying to get some more on-topic discussions going). >> >>Here are two questions that have been running around my head: >> >>[snip] >>2. Several measurement techniques require a given phase relationship >>(e.g., quadrature) between DUT and reference. For HF frequencies (ie, 5 >>or 10 MHz) is there a *practical* phase shifter design covering 180+ >>degrees that doesn't involve switching various lengths of coax in and >>out of the line? > > Why the aversion to coax delay lines? They are simple and reliable. > The reason will help people to tell what alternatives would be best. > > Joe > > _______________________________________________ > 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.