[time-nuts] Trimble TB replacement options???

Sat Oct 12 12:11:29 EDT 2013

Very tempting.  I just ordered 100 and 1000MHz VCXOs from Fox 
Electronics, with the intent of locking them to my GPSDO.  I think, in 
perusing various lists, I did see some 10 MHz devices at relatively 
affordable prices.  (Somebody on this list pointed me to Fox, don't 
remember who.)

A DIY GPSDO would be WONDERFUL!  Already have a couple of Jupiter GPS 
boards with 1pps output....

Jim

On 10/12/2013 11:54 AM, Chris Albertson wrote:
> What is needed now is a easy to assemble DIY GPSDO.  In the past 
> people lost interest in such becuase you could buy a TB for $90.  I'd 
> think today now that we have $10 microcontroller boards that have USB 
> connections and are self-programming we could make a GPSDO controller 
> with justone of those boards and two cheap chips (plus a GPS and XO.)
>
>
> On Sat, Oct 12, 2013 at 7:41 AM, Jim Sanford <wb4gcs at wb4gcs.org 
> <mailto:wb4gcs at wb4gcs.org>> wrote:
>
>     I looked into the Jackson Labs products.  Prices range from nearly
>     $400 to almost $1300 for a dual-oven unit.
>
>     Seemed reasonable, but higher than I'm willing to go at the
>     moment. Maybe down the road....
>
>     Had a Z3801 which worked for 10 years, then failed - experimenter
>     who bought it found the XO some 40 Hz off -- not correctible
>     without invasive repair.  I think he gave up and kept it for parts.
>
>     I bought one ot the TB clones off the e-place, and am not yet sure
>     whether it is good or not.  It spends more time in RECOVERY mode
>     than PHASE LOCKED, and the VCO voltage takes large jumps every
>     time the number of satellites changes.  Still scratching my head.
>
>     Good luck!
>     Jim
>     wb4gcs at amsat.org <mailto:wb4gcs at amsat.org>
>
>
>     On 10/12/2013 9:16 AM, Mark C. Stephens wrote:
>
>         As per Bob Camps Wisdom below, most of the thunderbolts and
>         Z38XX have been well picked over, the remaining ones are
>         usually poor in some way.
>         The main problem seems to be unstable oscillators, invasive
>         repair is required to meet specifications.
>
>         --marki
>
>         -----Original Message-----
>         From: time-nuts-bounces at febo.com
>         <mailto:time-nuts-bounces at febo.com>
>         [mailto:time-nuts-bounces at febo.com
>         <mailto:time-nuts-bounces at febo.com>] On Behalf Of Bob Camp
>         Sent: Saturday, 12 October 2013 10:52 PM
>         To: Discussion of precise time and frequency measurement
>         Subject: Re: [time-nuts] Trimble TB replacement options???
>
>         Hi
>
>         All of these gizmos come on the market cheap when they are
>         being scrapped out. Once that process is over for a generation
>         of parts, the pieces climb. There are only a few working
>         strategies:
>
>         1) Buy several when they first come out.
>         2) Pay the going rate many years later.
>         3) Switch to other gizmos with other cost / feature tradeoffs.
>
>         In this case the likely tradeoff is to one of the Nortel /
>         Trimble units or to one of the later HP boxes. The Nortel /
>         Trimbles are in the sub $150 price range delivered. The later
>         HP's are a bit more expensive. The Nortel / Trimble's come
>         mainly from RDR Electronics on the e-place. The HP's come from
>         the other side of the Pacific Ocean.
>
>         One other option - before I'd pay $300 for a possibly broken
>         TBolt (I've got a few of those), I'd do an email to find out
>         what a brand new GPSDO (with warranty) from Jackson Labs would
>         cost me.
>
>         Bob
>
>         On Oct 11, 2013, at 8:51 PM, Paul <tic-toc at bodosom.net
>         <mailto:tic-toc at bodosom.net>> wrote:
>
>             On Fri, Oct 11, 2013 at 7:24 PM, Frank Hughes
>             <hp_ciscovss at yahoo.com <mailto:hp_ciscovss at yahoo.com>> wrote:
>
>                 Does it seem like the Trimble Thunderbolt units are
>                 becoming scarce, and commanding prices accordingly?
>
>             The "inexpensive" used Thunderbolts predate my interest in
>             GPSDOs so I
>             can't speak to relative prices but if your budget is ~
>             $300 they're
>             still readily available.  The various 2PPS Trimble GPSTM
>             boxes/boards
>             seem to occupy the < $200 Thunderbot-like niche and some work
>             (somewhat) with Lady Heather if you're fond of that program.
>
>             Various Z38xx devices are also candidates if you just want an
>             inexpensive GPSDO in-a-box with 1 and 10M Hz (some with
>             multiple
>             outputs) if you are willing to deal with
>              it's-not-quite-a-Z3801
>             behavior.
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>
> -- 
>
> Chris Albertson
> Redondo Beach, California