[time-nuts] Trimble replacement part-2

Robert Atkinson robert8rpi at yahoo.co.uk
Sun Oct 13 09:47:01 UTC 2013


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
_______________________________________________
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_lists.febo.com mailing list