From: terrell.michael.a@gmail.com   
      
   On Monday, January 27, 2020 at 1:56:59 PM UTC-5, default wrote:   
   > On Sun, 26 Jan 2020 19:12:23 -0800 (PST), tabbypurr@gmail.com wrote:   
   >    
   > >On Sunday, 26 January 2020 21:51:32 UTC, default  wrote:   
   > >> On Sun, 26 Jan 2020 13:00:49 -0800 (PST), George Herold   
   > >>  wrote:   
   > >> >On Saturday, January 25, 2020 at 7:04:53 AM UTC-5, Michael Terrell wrote:   
   > >> >> On Friday, January 24, 2020 at 8:07:41 AM UTC-5, default wrote:   
   > >> >> > On Thu, 16 Jan 2020 10:42:28 -0800 (PST), Michael Terrell wrote:   
   > >> >> > >   
   > >> >> > >The TS-382 series were military versions in transit cases. They had   
   a vibration reed frequency meter to display 60 Hz and 400Hz. The insides were   
   protected for Jungle use, and the one I have, (TS-382/F)has heat strips to   
   drive moisture out of    
   the cabinet.   
   > >> >> >    
   > >> >> > I remember those from navy ET-A school.  They had two resonant reeds,   
   > >> >> > for 40 HZ and 400 HZ.   
   > >> >>    
   > >> >>    
   > >> >> I've never seen one for 40 Hz. Only 60Hz or 60Hz and 400Hz.   
   > >> >   
   > >> >Niagara Falls use to send out 25 Hz power.. (maybe three phase,   
   > >> >but I couldn't find a reference.)    
   > >> >   
   > >> >George H.   
   > >>    
   > >> Looks like they still use 25 HZ...   
   > >>    
   > >> The Sitras SFC Plus frequency converters transform 60 Hz power into   
   > >> “functional, reliable” 25 Hz electricity. The converted electricity is   
   > >> then transferred from Metuchen to the various systems that power   
   > >> [catenary] on the NEC. The upgraded converter technology enables   
   > >> increased power output, more than doubling the facility’s capacity,   
   > >> from 25 MW to 85 MW.   
   > >>    
   > >> 2018   
   > >> https://www.railwayage.com/passenger/intercity/siemens-upda   
   es-nec-traction-power-station/   
   > >   
   > >17 or 25Hz gives large motors better get-going ability from start. The   
   pulses help overcome stiction.   
   > >   
   > The actual traction motors use DC, not AC.     
   >    
   > I suspect that may be changing because it sounds like modern subway   
   > cars are being fitted with DC to 3 phase to run the motors, but the   
   > third rail is still DC.   
      
   There ere no third rails in mines. Just very large and heavy flexible HV   
   cables. Read about some of the largest coalmines, like the Peabody Coal   
   company had. There was even a song written about it.   
      
   https://www.youtube.com/watch?v=efa6zlDQ1kc   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)