[time-nuts] Trimble replacement part-2

[Jim Sanford]

Someone earlier suggested a group buy of the Jackson Labs device.  I 
would be interested.

As for power supplies, my Nortel-TB is on an analog power supply, 
deliberately.  I do intend to put a scope on it, and see if it may be 
contributing noise to the "issues" I see.  (I'm wondering if it has 
sufficient high frequency bypassing, and sufficient bulk capacitance to 
deal with transients.)  If it is, I will put it on battery, with the 
analog supply as a charger...

More I think about it, the more I like the Jackson Labs devices. 
Especially that they work with the GPSCON software (I think).
Jim
wb4gcs at amsat.org

On 10/13/2013 5:47 AM, Robert Atkinson wrote:
> Hi Frank,
> I would NOT put the spare TB on a PC powersupply. Check out both TB's on the bench using decent linear supplies. I don't like using PC supplies on critical equipment. They are typically designed for a specific (high) load on one output (5V on early ones 12V on more modern) to maintain regulation on the other outputs. They are designed down to a cost and are often not great in terms of suppressing spikes and surges. You are running a sub 15W TB on a 100-300W PSU. And then there is the phase noise issue. Whay put a $30 PSU on $1000 Frequency standard? A 3 line analog supply is easy to build at most 2 transformers two bridge rectifiers a few capacitors and 3 78xx series regulators. Surplus (or new) linear supplies are available, I use a HTAA-16W-AG by Power-One / Condor / SL Power,  like ebay items 300956540240 300956540566 ($15 each). Even new from Mouser they are under $100. These high quality 100% duty cycle units are slightly underated for start-up
>   current on the +12V rail, but with virtually no load on the -12V and low load on the +5V it works fine. I'm in the UK on 50Hz mains so its worse case, the PSU has 20% more capacity on 60Hz.
> Bin the switcher!
>
>
> Robert G8RPI.
>
>
> ________________________________
>   From: Frank Hughes <hp_ciscovss at yahoo.com>
> To: "time-nuts at febo.com" <time-nuts at febo.com>
> Sent: Saturday, 12 October 2013, 22:49
> Subject: [time-nuts] Trimble replacement part-2
>   
>
> Hi,
> Well, now I have determined that the TB
> is actually bad and/or the goofy PC power brick is no longer making
> correct volts.
>
> http://i180.photobucket.com/albums/x257/fish1_07/am/trimble_trouble_zps70b440a7.png
>
> I had one spare Trimble remaining to
> replace it with.
> Not sure what model the new one is, the
> enclosure is red and a different form factor than the smaller anodized
> Aluminum TB that failed.
>
> New one works fine:
> http://i180.photobucket.com/albums/x257/fish1_07/am/Trimble_replaced_10_12_2013_zps5042b487.png
>
> Funny thing, my HP 59309A Clock had
> stopped working, I thought it had a failure too, but when a stable
> 10Mhz signal appeared at the HP input, the ancient HP clock is back
> to abby-normal again!
> I should remember that the HP is also a "miners canary" for the TB...
>
> In a state of delusion, I sent an EM to
> Jackson Labs sales to see if they will sell a Fury
> to an individual..can't imagine what
> Quan-1 $$$ is going to be...
>
> 73
> Frank
> KJ4OLL
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