[hpsdr] Trimble Thunderbolt & Excalibur

[Chris Smith]

Hi

I wonder if some kind soul can throw some light on a problem I'm having with my Trimble Thunderbolt please?

I bought the unit from an outlet in California last November but, due to circumstances, have only just got around to using it with Excalibur. 

The first thing I noticed was the Temp pane in TBOLTMON shows -30.8C. Jeff Cook G0AFQ sent me a screen capture of his set-up which shows a temp of 36.7C - more like what I would expect to see. TBOLTMON doesn't show any Critical or Minor alarms and the Lat, Long & Alt are all nominal.

The next thing I checked was the output from the 10MHz osc. The amplitude displays serious jitter of several 10s of mVs.

The PPS output displays a 10uS pulse at 1 second intervals, so that appears to be working.

I connected this signal to Excalibur and jumpered for external osc. This is when I became seriously depressed. The phase lock lights alternate red/green at several 10s of Hz. I can only assume that either I have made a serious error in constructing Excalibur or the Thunderbolt output differs from the TXCO on Excalibur by several 10s of Hz.

I've checked the power rails to the Thunderbolt. All were within a few mV of nominal and clean on a 'scope. So it isn't a problem caused by the power supply.

Has anyone else seen these problems? Can anyone suggest a cure?

I'm happy to approach the supplier of the T/B and see if they will exchange the unit but I thought I'd pick a few brains first.

Cheers

Chris
G4NUX