10MHz GPSDO reference

OH2NLT 13.11.2011


Used timing GPS receiver modules are available at reasonable price from Ebay. I purchased Trimble ThunderBolt module and antenna for it. Just had to find suitable power supply and enclocure for my new lab equipment.

Old ISDN router appeared to be perfect donor for the PSU and box. GPS module needs +5, +12 and 12V operating voltages. ISDN router PSU provides everything what was neded also enough power.

Same 10MHz-distribution amplifier was used for this project what I designed for the Rubidium reference. Documentation can be found from Rubidium ref proect page. Some gain adjustments was neded to get the amplifier board match with the GPS 10MHz output.

10MHz output signal

Scope view



GPS & distribution amp Installation ready. Small fan was left in the box but not connected.

Box cloced and re labeled.

New frequency standard found its own place in the lab self.

Compared with the Rubidium oscillator. Hp53131A reference comes from the GPS and CH1 signal from the Rubidium oscillator.

Thunderbolt GPSDO can be monitored and controlled with very nice control program written by John Miles KE5FX

GPS antenna mount was bolt on arm done from the material what heppened to be available.

Fortunatelly space was found for the new antenna.