[time-nuts] Confusion over Thunderbolt - noob is going crazy

[Gregory Beat]

Taka -

The majority of the surplus GPSDO units come from the mobile/cellular telecommunication companies since the late 1990s.  Surplus equipment occurs due to Service advances (2G—>3G—>4G/LTE—>5G), Technology upgrades/obsolescence, and  Consolidation/merger of telecom companies.
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NO Distinct Advantage in owning the Trimble Thunderbolt models versus other options,
some would note a few disadvantages (now 10 years later, like 1024-week rollover).
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A large number of Trimble Thunderbolt GPS Disciplined Oscillators (GPSDO) appeared on the surplus market in 2007 and 2008.  Majority of these were the “THIN Model” (no internal DC-DC converter).

At that time (2008) TAPR Time-Nuts had a Group Buy, and offered a KIT (~ $225).
Tom Van Baak (tvb) and other members of Time-Nuts tested units and packaged these with a tri-voltage (+5, +12, -12) power supply for Group Buy participants.
http://www.leapsecond.com/pages/tapr-tbolt/

W6AER built (DIY) this Rack Case for his surplus Thunderbolt & power supply.
https://w6aer.com/10mhz-gps-disciplined-oscillator-gpsdo-trimble-thunderbolt/
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The RED Thunderbolt model has a Larger case because it contains the SMPS (24V to Tri-Voltage) as well as the GPSDO (THICK model). 
http://trl.trimble.com/docushare/dsweb/Get/Document-10015/
This specific model is no longer mfg. or supported by Trimble (no firmware updates provided).  Surplus “Red” units have appeared from 911 telephone centers (past 5 years), since the RED model does not handle the 1024-week rollover.  The “cheapest” has been ~$250 (2018 price, I paid) for a surplus unit from a Pennsylvania 911 center.
https://en.wikipedia.org/wiki/GPS_Week_Number_Rollover
The Lady Heather software (Mark Sims) “notes & corrects” the 1024-week rollover occurrence with these Trimble units, on its computer display.
ANY OTHER Solution would also have to “Correct” for the 1024-week rollover.
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The BLUE Thunderbolt E model is Current Trimble Production ($$), hence RARELY seen as Surplus.  Trimble refreshed their hardware, simplifying design (newer components).
http://trl.trimble.com/docushare/dsweb/Get/Document-383329/
Trimble Thunderbolt-E Product Page
https://www.trimble.com/Timing/thunderbolt-e.aspx
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THUNDERBOLT Frequently Asked Questions (from Group Buy, a decade ago).
http://www.ko4bb.com/getsimple/index.php?id=time-nuts-thunderbolt-gpsdo-group-buy

g. beat, w9gb
chicago
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Date: Fri, 15 Nov 2019 04:02:56 +0000 (UTC)
From: Taka Kamiya <tkamiya9 at yahoo.com>
To: Time Nuts Group <time-nuts at lists.febo.com>
Subject: [time-nuts] Confusion over Thunderbolt - noob is going crazy

I have several GPSDO, BUT I don't have a TRUE Trimble Thunderbolt.  I want one.
There seem to be infinite variations of them.  So far (I have been looking for a week), there are no good summary (or even a summary) of various types and how they are different.
I know there is a thin type that looks to be 1" or so thick, and thick type that is about double that.  I know one model has a Blue label (Thunderbolt E) and an earlier model had a Red Label (Thunderbolt).
I know there are differences in the Internal Crystal Oscillator/Oven.

Spending $1500 for new one is out of question, but price seems to vary from $150 to $500 for used ones.  Since most of these surplus units now come from China, I'd think they are reclaimed equipment.  Is this assumption right?
Any reliable source?? 
I am a bit skeptical with the surplus market the way it is.  Are they all telecom quality??
Thank you very much.
----------------------
(Mr.) Taka Kamiya
KB4EMF / ex JF2DKG