[time-nuts] Tbolt failure modes

[Bob Camp]

Hi

The first thing to check is the soldering job on the DB-9 connector. Second thing to check is the RS-232 level translator IC. (RS-232 in should create TTL etc)

Bob

On May 8, 2012, at 5:52 PM, bg at lysator.liu.se wrote:

> Hi group!
> 
> Just got a few Thunderbolts. It is a few PN 39448-61 and one PN 38223-61.
> Date codes from 9932 to 0025. This is the "normal" version with a 24VDC
> power board and Tbolt board integrated in a small AL box with red
> markings. One of the receivers is having a problem. Measuring from the
> outside there is:
> 
> 1) Takes the same amount of power as the working units.(to the
> resolution measured)
> 2) Has 10MHz output.
> 3) Has 4.9VDC on antenna center pin.
> 4) -8.9VDC stable on rs232 Tx pin (pin2 in DB9)
> 5) 10MHz is 0.7Hz off after many power on hours with known good antenna
> 6) TP9 & TP10 (close to the GPS board power connector) has 4.9VDC
> 7) Tboltmon will not talk to the board.
> 8) There is no serial output at all from the Tbolt.
> 
> Differences compared to a good Tbolt
> 
> 1) Tboltmon will ofcause communicate.
> 2) After locking 10MHz will be very close to nominal
> 3) TP9 and TP10 shows a square wave (ca 7V pp, 9.795625000kHz)
> 
> I have looked at Tom's page at
> 
>  http://www.leapsecond.com/tbolt-faq.htm
> 
> Brooke's at
> 
>  http://www.prc68.com/I/ThunderBolt.shtml#IC
> 
> and John's at
> 
>  http://www.ke5fx.com/tbolt.htm
> 
> Are there other good Thunderbolt sites?
> 
> Has anyone done debugging of faulty Tbolts? Comments on what might be
> wrong with my faulty unit? (I am not that experienced in hardware
> debugging...)
> 
> --
> 
>  Björn
> 
> 
> 
> 
> 
> 
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