[time-nuts] accurate 60 hz reference chips/ckts
Tom Van Baak
tvb at LeapSecond.com
Thu Dec 14 18:41:35 UTC 2017
Pat,
> They drift a few seconds in the course of a few days, and wander back and forth.
Yes, it's normal for AC mains to drift around by a few seconds over a day but it usually stays roughly on-time over weeks and months. Here's an old example of monitoring mains time & frequency for 45 days:
http://leapsecond.com/pages/mains/
> Does a TCXO or similar exist in a small package that provides 60 hz ticks?
If you have 10 MHz (XO, TCXO, etc.) you can convert to 60 Hz using a $1 PIC divider:
http://leapsecond.com/pic/src/pd60.asm
http://leapsecond.com/pic/src/pd60.hex
/tvb
----- Original Message -----
From: "Patrick Barthelow" <apolloeme at gmail.com>
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Sent: Thursday, December 14, 2017 8:42 AM
Subject: [time-nuts] accurate 60 hz reference chips/ckts
> PIcked up a couple of large size Radio Shack 63-960 LED clocks with
> Settable alarm, at local Goodwill store. $3.00 ea work great see across
> room, loud Alarm, etc...
>
>
> Barely missed, by seconds, getting a classic Hallicrafters General coverage
> receiver
> (not like say, S-38) but a larger light green metal box. nearly perfect
> condx. $25.00 with the famous h logo speaker probably late 50s Vintage.
> :-( Dang...
> Checked LED clocks by ear and eye with WWV, They drift a few seconds in
> the course of a few days, and wander back and forth. Thought AC mains
> frequency was tighter than that. They use an LM 8560 Clock chip. Uses a
> switchable AC mains frequency reference pin 50/60 hz.
> Want to provide an accurate (relatively accurate) 60 hz reference to the
> chip. Some room inside for custom modifications. Does a TCXO or similar
> exist in a small package that provides 60 hz ticks?
>
> Best, 73, Pat Barthelow AA6EG
> apol <apolloeme at gmail.com>loeme at gmail.com
>
>
> *"The most exciting phrase to hear in Science, the one that heraldsnew
> discoveries, is not "Eureka, I have found it!" but:*
> "That's funny..." ----Isaac Asimov
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