[time-nuts] Up And Running

[Timeok]

Il 2012-09-28 16:53 George Race ha scritto:
> Hello to all the Time-Nuts:
>
>  I Have been acquiring parts for a few weeks and finally have a
> Thunderbolt-Trimble system up and running.
>
> Though I would share a few pictures of what I did and how it looks 
> now that
> it is all together and working.
>
>
>
> First, here is an overall look at what I have put together.
>
>
>
> http://www.mrrace.com/TrimbleGPS/TrimbleParts.jpg
>
>
>
> I had to use the attenuator to reduce the amplitude of the 10MHz 
> signal from
> the Trimble.  It was overdriving the Extron causing distortion in the 
> output
> waveform.  The 6db attenuator is just what was needed.
>
>
>
> I was running on a temporary old GPS antenna mounted on the edge of 
> my
> garage roof for a while.  I ordered a Trimble antenna from China, 
> took about
> 10 days to get here.  What a difference that made in the overall 
> signal
> strength and stability of the unit.
>
> Here is a Lady Heather shot after running on the antenna over night.
>
>
>
> http://www.mrrace.com/TrimbleGPS/MyLadyH.jpg
>
>
>
> I am still having trouble knowing what all the indicators on the 
> screen
> mean, but it appears that everything is working.
>
> Sure wish there was an index somewhere that told what each and every 
> thing
> on that screen means!
>
>
>
> As I mentioned, the antenna arrived yesterday and I built a mount and
> installed it yesterday afternoon.
>
> Though you might like to see what I ended up doing.  We have a lot of 
> rain,
> snow, and ice here in Michigan, so I wanted to do something to 
> protect the
> antenna and connectors the best that I could from the elements.  
> First, here
> is a picture of the antenna from China, along with the adaptor cable 
> to get
> it to an “F” connector to hook to my 50 foot RG6U cable with “F” 
> connectors
> on each end.
>
>
>
> http://www.mrrace.com/TrimbleGPS/TrimbleAnt.jpg
>
>
>
> Here is the mount that I built.  I am going to put it on my TV 
> antenna mast
> that is mounted on the house.  The 10 degree elevation pattern should 
> see
> open sky in all directions.
>
> The mount is a piece of aluminum angle with a mast clamp on one end, 
> the a
> sealable tea container on the other.  The container is one of those 
> push
> button kitchen containers that has a very tight air seal when the 
> button on
> the lid is pressed in.  It really holds well, and you cannot remove 
> the lid
> when it is locked into place.  Also this configuration makes it 
> really easy
> to get to the antenna and connectors if necessary.  Just release the 
> button
> on the bottom and lift off the unit.  The “F” barrel connector 
> through the
> side of the container makes it easy to just unscrew the cable if 
> necessary.
> The seal on the container is about ¾ of an inch wide, and really 
> holds on to
> the inside of the container.
>
>
>
> http://www.mrrace.com/TrimbleGPS/BuildingTheMount.jpg
>
>
>
> To hold the GPS antenna in place at the top of the container, I cut a 
> small
> aluminum plate, carefully drilled 3 holes for 2-56 hardware through 
> the top
> of the container, using the aluminum plate as a template.  The 
> antenna is
> “clamped” into place by bolting the plate up against the bottom of 
> the
> antenna, inside of the container.  You can see from the next picture 
> how the
> cable connectors and antenna wire is coiled up in the bottom of the
> container, and terminates on the “F” barrel connector inside.  Looks 
> like it
> is all ready to put up on the roof and connect to the cable.
>
>
>
> http://www.mrrace.com/TrimbleGPS/ReadyToPutUp.jpg
>
>
>
> Here it is, mounted about 25 feet above the ground, below the TV 
> antenna.
>
>
>
> http://www.mrrace.com/TrimbleGPS/MountedHigh.jpg
>
>
>
> And here is a close up of the finished installation.
>
>
>
> http://www.mrrace.com/TrimbleGPS/UpAndWorking.jpg
>
>
>
> A lesson to be learned, about “F” connector barrels!
>
>
>
> When I hooked up the basement end of the cable, total disappointment! 
> On
> the screen it said in yellow letters, “Antenna Open.”
>
> As I had tested the system end to end, BEFORE I put it all in the 
> container,
> the only place that could be a problem was that “F” connector barrel.
>
> I brought the container back down to the bench and carefully looked 
> at the
> connections.  It was so simple, and I had caused the problem during 
> early
> bench testing of the cables.  The jumper cable from the antenna to 
> the inner
> part of the “F” connector has a extremely small diameter center 
> conductor.
> On the other hand, the RG6U cable has a greatly oversize, compared to 
> RG59U
> cable, center conductor.  In testing I had pushed the RG6U center 
> conductor
> into both ends of the “F” barrel.  This pushed the center part of the
> connector to its limits, and it did not close back down when the 
> cable was
> removed.   I installed a nice brand new “F” barrel into the side of 
> the
> container.   Starting the “F” connector on the inside barrel 
> connection, I
> could feel the center conductor pushing into the connector.  Taking 
> it all
> back to the roof, tightening the “F” connectors in place, solved the
> problem!
>
>
>
> Somebody is probably going to ask, what I am using this system for?  
> I have
> an HP synthesized signal generator and a Racal-Dana digital frequency
> counter that both have provisions for a 10MHz external standard input
> signal.  I wanted to have them driven by the GPS system to give me 
> the best
> possible accuracy I could get on both instruments.
>
>
>
> Picture of the messy work bench below!
>
>
>
> http://www.mrrace.com/TrimbleGPS/TestEquipment.jpg
>
>
>
>
>
> Comments and suggestion are always welcomed,
>
> George
>
>
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George and now?
hi!


Luciano
timeok