[time-nuts] ACE-III GPS receivers

Didier Juges didier at cox.net
Sat Jan 27 20:31:02 EST 2007


Hi Jason,

I have looked everywhere for the 2mm hardware, and while I could find 
connectors, the ribbon cable itself seems unavailable in short length 
off-the-shelf. I will check Mouser (again...)

Receiver-wise, I think I am covered at the moment, with 2 Jupiters and 
the 3 ACE-III. I can build GPSDOs until the birds fall off the sky :-) I 
also have a Trimble Thunderbolt GPSDO which works great. I have several 
projects going and it will be interesting to compare the results.

For the antenna port, I have a couple of SMB-SMB cables recovered from a 
defunct Tek spectrum analyzer plug-in. So, I cut one in the middle and 
soldered a BNC, from which I can go to anything. The Jupiter uses a 
different style of antenna connector for which I had no mate, so I 
soldered a small coax cable with an SMA at the other end to the bottom 
(solder side) of the PWB. That would work with the ACE-III as well I 
suppose.

At the moment, I am using a small puck-like antenna (against the ceiling 
in my upstairs ham shack) with my Thunderbolt GPSDO, but I also have a 
Trimble Bullet antenna (which came with the Thunderbolt but did not work 
too well with it, maybe because of location). I have used the Bullet 
with both the Jupiter and the ACE-III, and with the antenna in the same 
location, either receiver works better than the Thunderbolt (gets better 
signal from the birds). I also have a brand new HP/Symmetricom HP 58532A 
antenna also that's just waiting to be installed. I paid a lot more than 
$10 for it, even excluding shipping :-( I have two of the puck antennas 
since each of the Jupiter came with an antenna.

It seems the Thunderbolt is less sensitive than either the Jupiter or 
the ACE-III receivers, and the puck antenna, either because of it's 
location or its design, seems more sensitive than either of the others, 
so the Thunderbolt runs from the puck and it is happy. I am not sure 
what I will do ultimately. If the Symmetricom antenna works as well as I 
hope once installed outside, I will probably put a power splitter to 
drive the other receivers, and keep the puck and the Bullet in the shack 
for experimentation.

Eventually, I would like to make a couple of portable (battery operated) 
GPSDOs with the ACE-III (because of it's low power) to use for weak 
signal, narrow band microwave ham experimentation (10 GHz and higher). 
This requires stability and accuracy of about 1 Hz or better at 10 GHz 
for several hours, including transportation and operation outside under 
varying temperature.

So as you can see, I am not short of opportunities for experimentation 
and I have all the hardware for it, I just need the time.

Didier KO4BB


Jason Rabel wrote:
> Glad to hear you did not fry the module! I never really looked at the pinout
> to see where the power goes if you reverse it.
>
> I'm glad Chris chimed in about the Port1 / Port2 thing, I forgot to mention
> that as another method that would probably be easier.
>
> Mouser has all the 2mm pins and everything that you could need, all
> reasonably priced.
>
> If you are looking for some cheap GPS receivers, the eBay person
> "isellreturns" has been listing "OEM GPS MODULE WITH MCX ANTENNA CABLE"
> individually, and also in lots of 5 and even 10. You can look at their past
> auctions to see the prices they have been going for. They are actually older
> Novatel SuperStar II receivers (not firmware upgradeable, but I have a
> couple and they work fine). Also that person has been listing some
> Magellan/Ashtech receivers but I am not familiar with that particular unit.
>
> What did you do for a connection to the SMB antenna port?
>
> I have all my parts for one of those simple gpsdo designs, I just haven't
> had a chance to put it together, I'm still fidgeting with my shera board
> finalizing everything in its new little box.
>
> As for an antenna, I don't know if you were looking for any cheap little
> thing or wanted the nicer models. The eBay person "mysty4ever" listed some
> that looked like the Symmetricom 58532A, but had the auction labeled as a
> Garmin Magellen 469357A. It ended at $10.50 + $10 for shipping (I only bid
> $10 since I didn't really need another one and got sniped at the last few
> seconds)... $20 would have been a heck of a deal, realistically I've seen
> them going for more like $30-$40 (that's with shipping).
>
>
>   




More information about the time-nuts mailing list