[time-nuts] EES RC 1454 & 100DB MSF/GPS clock

Robert Atkinson robert8rpi at yahoo.co.uk
Fri Nov 30 18:25:14 UTC 2012


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. 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. 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.
 
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.
_______________________________________________
time-nuts mailing  list -- time-nuts at febo.com
To unsubscribe, go to  
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the  instructions there.
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


More information about the time-nuts mailing list