Later I plan to add circuitry to process the Thunderbolt outputs for wider uses.
Right: Temporary installation of the amplified GPS antenna used
with the Thunderbolt.
Radome antenna mount for an Odetics GPStar time and frequency system. The Odetics system housed the GPS antenna and a downconverter in a sealed radome. Unfortunately the construction details caused many units to suck in water past the O ring and then keep it trapped. These radomes ingested water over a number of temperature cycles. Many units failed when they filled up with water.
I drilled a small hole in the bottom plate to let the water out. The dark splotch on the radome is from paint flaking off.
The Odetics had a nice little LED display that showed system status
or UTC time.
My Odetics never seemed to phase lock its 10 MHz signal.
After a while the Odetics complained that its navigation failed
and stopped doing its thing.
When I removed the radome I inspected it for water ingestion and found none.
The next artifact in my descent into Time-Nuttiness was a used Rubidium Frequency standard. A number of FE-5680A units have shown up on Ebay at low cost. These units generate so much heat they are uncomfortably hot to the touch. This unit is mounted outside the case. A 15 volt power supply from an old laptop provides most of the power for the FE-5680A. The Thunderbolt draws little current from its 5 volt supply, leaving plenty for the FE-5680A.
I had planned to add a 10 MHz distribution circuit to drive the unused BNC connectors seen here.
In the meantime I noticed the 10 MHz signal from the FE-5680 was not as good as the signal from the Thunderbolt. In addition, the Thunderbolt 10 MHz was several Db stronger. If something happened to the GPS satellites chances are I would not have a need for an ultra accurate 10 MHz reference anyway.
I now have the Thunderbolt's 10 MHz output daisy chained to the Flexradio 1500,
Advantest U3641, and Racal-Dana 1992 using BNC T connectors. A 50 Ohm
terminator is used on the far end of the chain.
This is the same topology used in 10 BASE 2 Ethernet.