[time-nuts] Tbolt failure modes

Ed Palmer ed_palmer at sasktel.net
Fri May 11 17:38:32 UTC 2012


Are there multiple hardware versions of the Tbolt (other than the 
Tbolt-E)?  My Tbolt has an Intersil 232IBE dual TTL to RS232 converter - 
similar to MAX232.  It generates it's own -12V.  This is the version 
shown on Brooke Clarke's Thunderbolt page:  
http://www.prc68.com/I/ThunderBolt.shtml

Ed


On 5/11/2012 10:56 AM, shalimr9 at gmail.com wrote:
> The -12V is only used to support the RS-232 driver. The CPU should be running and you should have discipline even without the -12V
>
> Didier KO4BB
>
> Sent from my BlackBerry Wireless thingy while I do other things...
>
> -----Original Message-----
> From: "J. L. Trantham"<jltran at att.net>
> Sender: time-nuts-bounces at febo.com
> Date: Tue, 8 May 2012 21:29:06
> To: 'Discussion of precise time and frequency measurement'<time-nuts at febo.com>
> Reply-To: Discussion of precise time and frequency measurement
> 	<time-nuts at febo.com>
> Subject: Re: [time-nuts] Tbolt failure modes
>
> I had a failure of my -12 V supply that interrupted communications that was
> resolved by fixing the -12 V supply.  You might want to make sure you are
> getting the -12 V supply in the unit.  I suspect your 24 V supply provides
> power to an internal supply that generates +12, +5 and -12 V.
>
> Might want to check if that is the case for your unit and if the -12 V is
> present.
>
> Hope this helps.
>
> Joe
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of bg at lysator.liu.se
> Sent: Tuesday, May 08, 2012 4:52 PM
> To: time-nuts at febo.com
> Subject: [time-nuts] Tbolt failure modes
>
> 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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