Morris used it in his timebase, as a divide-by-5 stage, and a dekatron, for a total of divide-by-50. That clicked a relay at 1 pps, to increment his stepper relay nixie clock. It was all mounted vertically on a pole, IIRC.
I bought a bunch of 6AS6 pentodes shortly afterward, and ran a few phantastron experiments. For a divider, it works like a one-shot, that needs its cycle to stop just short of the intended time. Say your using 50Hz as your syncing signal, and you want 10Hz out. Setup your RC timing of the phantastron to between no less than 80mS+ (say 81mS), and no more than 100mS- (say 99mS). That is adjust it to between 81 to 99mS. Split the difference, and put it at 90mS. As long as it stays in that range, it will output a sync'd signal at 100mS (10Hz). If you are using 60Hz, instead, then that 80mS+ (4 cycles plus) becomes 87mS+ (5 cycles plus). Keep the divisions small, since they're dependent on the RC component tolerances, and drift factors. On Tuesday, February 11, 2014 4:47:08 AM UTC-8, johnk wrote: > > I seem to remember Morris posting that he had used a Phantastron in > something of his? > > > > John K. > > > ----- Original Message ----- > From: > [email protected] <javascript:> > > To: > <[email protected] <javascript:>> > Cc: > > Sent: > Mon, 10 Feb 2014 12:59:49 -0700 > Subject: > Re: [neonixie-l] Elesta EZ10/A/B tester refurbished! > > > On 2/10/2014 12:44 PM, Tidak Ada wrote: > > Hmm could be, but despite I have heard about it, I am not familiar with > the > > Phamtastron circuit. Does it deliver a sine or an block/pulse at the > output? > > I have to look for some clear theory. > > > > eric > > Eric, > > Google does not help with the Phantastron, as someone borrowed the name > for a > product. > > The circuit is also called a Miller sweep circuit. It is used in > oscilloscopes, > and in old digital pulse circuits as a frequency divider. A pentode tube > generates a sawtooth wave, and is triggered to reset by a synchronizing > signal > only when near the end of the sweep. > > Look at any old HP frequency counter for a decimal divider using the > Phantastron. They were also used in early television sync generators. This > is > why the old television line count was a product of small numbers such as > the > US 525 line TV: 525 = 5 * 5 * 7 * 3. > > --David Forbes > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > To post to this group, send an email to [email protected]<javascript:> > . > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/52F92FB5.2060504%40dakotacom.net > . > For more options, visit https://groups.google.com/groups/opt_out. > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/39337ef8-cf1f-441d-8cb0-6d269c94396d%40googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
