Hi Chris,

Sorry, a 468 MHz GOES antenna won't help. That satellite timing service
ended 15+ years ago, another victim to the global success of GPS. So
antenna or not, the receiver has no signal to lock on to. That's why the
receivers are so cheap these days. There may be old postings in the time
nuts archives about all this. There are legacy web pages too. If nothing
else, here is a nice read [1]:

"The GOES Time Code Service, 1974–2004: A Retrospective"
https://tf.nist.gov/general/pdf/2013.pdf

What many people have done is convert the cute 1U Kinemetrics boxes into
DIY clocks. The ones with Sperry 7-segment Panaplex gas plasma displays
have a very nice look and are worth something. An Arduino or equivalent
could probably be used to hack the main board and get the display to
work. Kinemetrics manuals are available for free on several test
equipment manual archive sites.

/tvb

[1] Alternate locations:

https://tf.nist.gov/general/pdf/2013.pdf

https://www.nist.gov/publications/goes-time-code-service-1974-2004-retrospective

https://pubmed.ncbi.nlm.nih.gov/27308105/

On 1/31/2022 6:32 PM, NoName via time-nuts wrote:

    I used to own/use a 468-DC. They are, unfortunately, useless now
because NOAA stopped transmitting the UHF-based time code over the GOES
satellites in the early 2000's (this is, very likely, why it was so cheap).

    In short ... Even if you got a perfect antenna for the unit,
there's nothing for it to receive. I believe you'd be wasting your time
and money (unless you want to get -really- adventurous and try adapting
its innards to sync off GPS).

    Sorry to be the bearer of bad news...

On 31-Jan-22 18:32, NoName via time-nuts wrote:

--
Bruce Lane, ARS KC7GR
kyrrin@bluefeathertech.com
"Quando Omni Flunkus Moritati" (Red Green)

Hi Chris.

As Tom said before these units are cheap and abundant because they can
not be used as time reference even if you do find an antenna.

To make things worse the antenna itself is active (i.e. amplified) with
a down converter that will bring down the 468 MHz signal frequency to
around 40 MHz (around that !) and that is the frequency that the
receiver expects. You can find in the easily found service manual. So it
will not be an easy task to replicate it even if you would want to try,
and to make thing worse the original ones are really rare and expensive.

TrueTime made a converter called the G2G that would use the GPS signal
and translate it to the signal the 468DC expects to get from the
original antenna.  They are so rare I've been trying to purchase one for
years and never saw one listed.

But all is not lost, with an Arduino, a PIC or a RaspberriPi, a small
GPS receiver and a bit of work it can be modified as GPS based clock.
Or you can use NTP to synchronise your RaspberriPi.

Lots of fun for long winter nights !

Claude

Le 31/01/2022 22:02, kyrrin@bluefeathertech.com a écrit :