[time-nuts] EES RC 1454 & 100DB MSF/GPS clock
GandalfG8 at aol.com
GandalfG8 at aol.com
Sun Dec 2 13:48:53 UTC 2012
In a message dated 30/11/2012 18:25:52 GMT Standard Time,
robert8rpi at yahoo.co.uk writes:
Hi Nigel,
Connect did have some recently by this came from another? seller who is
from the same town. WoodsGroup are also selling them (item 390489973647 ) but
at excessive prices and without the antenna.
---------------
Hi Robert
I obviously missed more than I realised, the only one I found at first was
the one from Woods Group and must admit I was surprised at the price, but
think I've just found yours which looks to be a much more reasonable
investment:-)
---------------
The GPS mod seems to replace the PLL board and loops the LF signal
through. The GPS antenna unit also has an LF antenna input.
-----------------
The EES100s are sitting in their wooden transit cases right now and, as is
not unusual, I can see them but can't immediately get to them:-)
It's been a couple of years or so since I last did anything with these so
will have to try and dig one out during the week and refresh my memory.
I have got one of the antenna modules in front of me, a diecast box with a
Motorola ANT62301A2 GPS antenna mounted on top that looks much the same as
yours and very much like something intended to be portable and sited
alongside the EES100 at the operating position rather than up a pole somewhere.
The Oncore on this is a UTplus from late 2000 but the chip date codes on
the EES manufactured interface/CPU board range from 1993 to 96 so the Oncore
may have been replaced at some time. Either way this module strikes me as
being a bit more recent than I would expect the EES100s to be so, in this
case anyway, I'm wondering if this was an upgrade to older MSF units already
deployed, although they might have needed to be returned for modification
too.
---------------------
I traced the power (+5V &+12V) connections and hooked it up to a bench
supply without the antenna unit. The supply only has 500mA capability on the
12V and went into current limit. Tried a bigger supply and got smoke :-( A
pot core inductor on the PLL board was cooking. A bit of tracing and it's in
series with thr 12V supply and antenna connector. The was a short on the
MCx to BNC lead. It disappaered when I moved it so I'll leave it be for now.
I get a red power LED, green loop lock and 1PPS LEDs but no display. I've
got the GPS ant on a windowsill so I'll let it seet and see if anything
comes up.
-------------
Sorry to hear about the smoke and hope there's no lasting damage.
Despite being in a supposedly sealed enclosure there's deposits on the CPU
PCB and Oncore in this module that look to be damp related corrosion, not
too bad but looking like electrolytic action between some of the IC pins
and/or the soldering, so I'll need to go over it very carefully before
applying power.
More later.
Regards
Nigel
GM8PZR
--------------
Robert G8RPI.
________________________________
From: "GandalfG8 at aol.com" <GandalfG8 at aol.com>
To: time-nuts at febo.com
Sent: Thursday, 29 November 2012, 19:45
Subject: Re: [time-nuts] EES RC 1454 & 100DB MSF/GPS clock
Hi Robert
For some reason I missed these until you mentioned them but have just
taken
a look and am reminded very much of the similarly modified and boxed EES
100s that Connect Distribution were selling around 5 years ago.
Whilst this looks to be a much later unit both EES and Radiocode clocks
do
seem to have survived for an awful long time without too many significant
revisions to their hardware, internal hardware anyway:-)
I've seen a similar connector on one version of the RC060s but even that
mainly used conventional D connectors.
>From what I remember of the antenna modules on the EES 100s I got the
impression that the interface processor board extracted the timing
information
from the GPS signal and converted it into an MSF compatible signal to feed
the EES 100. I'm sure they didn't frequency convert from L band to 60KHz
but
just took the GPS data and started from fresh to generate their own MSF
compatible signal using that data.
I never tried to use one of the modified units straight from MSF but will
dig one out and try it, I don't think there was very much of a
modification
to the MSF receiver other than whatever was required to accept another
60KHz signal.
I suspect all the hard work was done in the antenna module and the MSF
unit was just used as decoder and display for the converted signal.
I may have missed something, nothing unusual there then:-), but it always
struck me as a rather odd way of accessing and displaying GPS timing data,
unless initially there was some pressure to find a quick fix utilising
existing approved equipment.
Regards
Nigel
GM8PZR
In a message dated 29/11/2012 18:58:47 GMT Standard Time,
robert8rpi at yahoo.co.uk writes:
Hi all,
I recently gave in and bought one of the EES (european electronic
systems)
RC1454 Radio Clock units that have been on ebay.co.uk for a while. The
one
I snagged came with a GPS antenna unit. The main unit has a label saying
"GPS Modified" The main box appears to be a MSF receiver but has no
obvious
power connector, just two rectangular multiway sockets, a 15W D plug and
two BNC's. It is a 2U high card frame with 15 PCBS and a LED display on
th
front. Vintage is late 1990's and both units look like new. The GPS unit
has
an early Oncore (R1211A) receiver and a PCB with a CPU etc. Two BNC'
marked
"MSF ANT" and RX looks like a mod for either MSF or GPS time. Does anyone
have any information on these beore I get into major reverse engineering?
Robert G8RPI.
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