The 8170 isn't smart enough to calculate the leapsecond immediately.
Instead, it uses its error correction routine which takes about 4
minutes after the event to realize that it is one second off, then
updates the time to match. Details quite far down the page at
Reviewing the schematic for the 8170 (I'll get back to the setting coil in the
clock a bit later), my unit does not seem to have Option 18 and A4-U4, the 8255A
at its heart, is not populated. A pity: it would have lovely BCD outputs and an
on-time pulse, just what I need. (The recent
Yahoo for real voltage power and current. Teletype style.
Yes indeed the old loop currents seriously worked.
No AA batteries here. ;-)
When will we see a pix of this unit??
Regards
Paul
WB8TSL
On Sat, Jan 21, 2012 at 9:25 PM, Brooke Clarke bro...@pacific.net wrote:
Hi Jim:
There are a number
Guess I simply did not read enough threads I see the pix.
Thanks
On Sat, Jan 21, 2012 at 9:42 PM, Brooke Clarke bro...@pacific.net wrote:
Hi again:
Sorry sent too soon.
The time constant of the loop is L/R. By increasing R the loop runs
faster.
Western Union ran the clocks from 200 Volts
On 1/22/12 1:56 PM, paul swed wrote:
Yahoo for real voltage power and current. Teletype style.
Yes indeed the old loop currents seriously worked.
No AA batteries here. ;-)
When will we see a pix of this unit??
It's my day off. :-)
Regards
Paul
WB8TSL
On Sat, Jan 21, 2012 at 9:25 PM, Brooke
OK Clark put some pix up.
On Sun, Jan 22, 2012 at 2:58 PM, Jim Hickstein j...@jxh.com wrote:
On 1/22/12 1:56 PM, paul swed wrote:
Yahoo for real voltage power and current. Teletype style.
Yes indeed the old loop currents seriously worked.
No AA batteries here. ;-)
When will we see a pix
On 2012/01/22 13:58, Jim Hickstein wrote:
On 1/22/12 1:56 PM, paul swed wrote:
Yahoo for real voltage power and current. Teletype style.
Yes indeed the old loop currents seriously worked.
No AA batteries here. ;-)
How far will I get with my 3 D cells? They make it wind nicely, but I've been
NICE!
Measure the resistance of the coil, and see what the current would be
with the voltage you want to use. Figure out what the current might have
been in the original installation. Ebay has an installation manual at
auction for these clocks, may have a description of the driving circuit.
In
Nice pixs
I would think that the setting winding would be of the old teletype loop
voltage and current and that the local winding battery as mentioned would
have been 3-6 VDC.
Nice looking clock lucky you to find such an instrument.
Regards
Paul.
On Sun, Jan 22, 2012 at 3:49 PM, Jim Hickstein
On 2012/01/22 14:56, Don Latham wrote:
NICE!
Measure the resistance of the coil, and see what the current would be
with the voltage you want to use. Figure out what the current might have
been in the original installation. Ebay has an installation manual at
auction for these clocks, may have a
Hi
Teletype loop current as in 20 ma through the coil via a dropping resistor off
of 125 vdc.
Bob
On Jan 22, 2012, at 4:06 PM, paul swed paulsw...@gmail.com wrote:
Nice pixs
I would think that the setting winding would be of the old teletype loop
voltage and current and that the local
Hi:
Synchronizer coil data at:
http://www.prc68.com/I/SWCC.shtml#SC - old 2 coil sync
and
http://www.prc68.com/I/SWCC2.shtml#SC - newer single coil sync
The WU central office used a 200 VDC supply and the loop drove a number of series connected sync coils. A large ceramic
tube variable
On 2012/01/22 15:29, Bob Camp wrote:
Hi
Teletype loop current as in 20 ma through the coil via a dropping resistor off
of 125 vdc.
Value for the dropping resistor? (I know, I'm an Extra, and I used to design
digital circuits, so I should know this stuff. But I've been in software for a
Hi Jim:
On web page:
http://www.prc68.com/I/SWCC2.shtml#SC
I have data from Henry W. that says 120 V (my memory was wrong on the 200 V)
and he says 250 ma.
This will give about 66 times faster response time than using 3 Volts.
I'm spending time on this because with low loop voltage the action
On 2012/01/22 17:03, Brooke Clarke wrote:
Hi Jim:
On web page:
http://www.prc68.com/I/SWCC2.shtml#SC
I have data from Henry W. that says 120 V (my memory was wrong on the 200 V) and
he says 250 ma.
This will give about 66 times faster response time than using 3 Volts.
Oh, I was reading the
Hi
6K is about right. The resistor was typically a big ceramic wire wound 10K
variable.
No guarantee it's right for a clock, just that it's right for a teletype.
Bob
On Jan 22, 2012, at 5:46 PM, Jim Hickstein j...@jxh.com wrote:
On 2012/01/22 15:29, Bob Camp wrote:
Hi
Teletype loop
Jim,
If your Western Union clock is similar to the type used in broadcasting,
you might want a setting pulse that starts at 59:59 and ends at 00:00 . The
reason is that at 59:59 the magnet pulls the second hand to the 12 o'clock
position and releases it on the hour. The one-second
Exellent intel, thanks! The face has a penciled legend I C Depot which I
suppose stands for Illinois Central, the railroad. But I would think mine works
the same way as all the others. The coil holds down a follower against a cam,
so the :59:59 thing makes sense. I will check this out by just
Hi Jim:
There are a number of options.
Ken's clock clinic sells what appears to be a No. 6 Battery that has a synchronization function for the Western Union
clocks.
But the problem with it and the drivers for slave clocks is that they use
fairly low voltage circuitry.
Stock Tickers and
Hi again:
Sorry sent too soon.
The time constant of the loop is L/R. By increasing R the loop runs faster.
Western Union ran the clocks from 200 Volts with a dropping resistor to get the
desired current.
When driven form say 12 Volts the clock response is sluggish, but when driven from
I have a Spectracom 8170 in the living room (who doesn't?), and a Western Union
time-service clock, a.k.a SWCC clock -- a nice one, in a 3-foot-high wood case.
I've been watching TV with this combination for years and years but never got
around to feeding a pulse from the 8170 to discipline
Some of the spectracoms like my 8170 actually put out timecodes and had
other options that were clever. It really depends on your comfort with
technology. Nothing at all wrong with a detector using 74ls30s or any
other mix of logic hitting a monostable and then a power transistor.
Snitching
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