From the Time-Nuts mailing list:
> Hi All,
> Have been thinking of getting a GPSDO and I'm looking for advice on what to choose
> between the Trimble Thunderbolt and the Z3805A.
> I haven't been able to find an ADEV comparison between these two units and am curious
> to know how their differences manifest themselves.
> Apart from the 12 satelites vs 8 what practical advantages are there in the 3805A over
> the Tbolt? With all the extra components there has to be something.
> I notice that the ocxo is not the large Docxo of the 3801A - which is better?
>
> Thanks
>
> Tim
Hi
I have a couple 3805's and more than a couple TBolts.
There are two 3805's, one has the double heated 10811 the other has a true double oven. The true double oven / later design is the one you want. Typically they have better TC and better ADEV at 10 seconds compared to the earlier part.
The TBolt has a much better GPS receiver in it and it is far more tweak able with the Lady Heather software. It's default settings are not as good as the defaults on the 3805. With some work they can be vastly improved.
The 3805 runs on a single 24 or 48 volt supply depending on the model you get. The TBolt needs +12, +5 and -12. Battery backup is easier on the 3805.
TBolts run $75 +/- 25. 3805's run $250 +/- $50. Shipping will be a bit more on the 3805.
The TBolt wins in bang for the buck and fun to tweak categories. The 3805 is the better plug it in and ignore it forever box.
Both will track a cesium well at 100,000 seconds and beyond. Both look a lot like GPS at 100 seconds or so. Both have some significant variation unit to unit.
Bob