The GPS engine shown is Navman Jupiter-T, part TU60-D120-041. Alas, in 2005 Navman discontinued manufacture of the Jupiter-T and my stock is exhausted. I can no longer supply the Jupiter-T.
However the standard Jupiter receivers TU30-D140-xxx and TU30-D410-xxx also have the 10 kHz output and can be used OK. It's a similar size, but the connector and pin-out is different. These receivers are often available on eBay. Before purchase, make sure that the firmware is v1.18 onwards. This is important; very early models ca. 1995-1996 e.g. v1.16, have substantial frequency jumps every 30 seconds, and the first production (e.g. v1.03) were not even synchronised to UTC. The firmware version is printed on the label, and is also emitted at start-up in an ASCII plaintext NMEA message.
The interface PCB (part 0082-004) is no longer available.
Here's the schematic (latest version of PCB); click on the diagram for full size.
PCB parts List (Part 0082-004)
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Ref Qty Description Farnell Notes
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X1 1 10 MHz VCXO or OCXO, DIL-14 package - or use wires from other
U1 1 SP233ACP-L 938-6572
U2 1 74HC86 380-490 or 109-4310, 959-1729
U3,4 2 74HC390 380-787 or 173-9940
U5 1 74AC14 147-0853
L1 1 10u Inductor 117-3864
C1,3 2 10u 6.3v tantalum 970-8200 or 110-0451
C2 1 100u 6.3v tantalum 970-8243 or 110-0455
C4 1 10u 35v (for 12V operation) 970-8570 or 110-0496, 165-0978
C5-8 4 100n 100v polyester 121-6445 or similar
R1 1 160k 1/8W MF12 934-2702 or similar
R2,3 2 22k 1/8W MF12 934-2842 or similar
R4 1 470R 1/8W MF12 934-3245 or similar
R5-8 4 200R 1/8W MF12 934-2770 or similar
Reg 1 Voltage Regulator LM7805CT 966-6095 For 12V operation
D1 1 1N4001 diode 956-4993 For 12V operation
Q1 1 BC547, BC107 etc NPN 109-7287 or 146-7869, 101-7673 etc
Terminals 2 Red Vero RS 262-2220 873-1209
16 Black Vero RS 262-2214 873-1195
DIL Socket 1 20-pin DIL socket 428-5608
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Note: Farnell Electronic Components is a world-wide supplier. But none of the parts is unusual, and will be available from your favourite dealer.
Using An External Oscillator
Here is a system using a better quality oscillator.
GPSDO using an Isotemp OCXO 134-10, often available on eBay. The ovenised oscillator has considerably better performance than a simple DIL packaged device, but at the cost of greater power consumption and increased size.
The Isotemp oscillator has an EFC range 0 to +8 Volt and the little circuit mounted on its pins is a simple DC amplifier with gain x1.6 to magnify the phase detector output from 0-5V up to 0-8V. Many people asked for this PCB, not realising that it was hand-made, masked, etched and drilled, one-at-a-time. So I had to have a batch made properly, 2-sided max copper and solder-resist (part 0083-001).
This OCXO has a sensitivity of 2 Hz/Volt (i.e. 3.2 Hz/Volt at the DC-amplifier input). Suitable PLL filter components are R1=160k, C1=100µF, R2,C2 not fitted.
Because the OCXO 10 MHz output is AC coupled, add pull-down 4k7 to 0V and pull-up 4k7 to +5V. These connections are to the OCXO output, and can be most easily mounted on the underside of the (green) PCB. The latest PCB (0082-004) has pads for these resistors.
In response to requests I supplied many of these IsoTemp-based GPSDOs built and tested. But I have no more IsoTemp oscillators. A photo. The manual.
Simple GPSDO Project - Summary of available items
Component Parts (supplied at cost) including world-wide shipping PCB: GPS Interface/PLL part 0082-004 0 remaining PCB: DC-Amplifier for Isotemp part 0083-001 0 remaining
Last updated: 2022 Jun 29
