Neximage Long Exposure Mod by Freddy Díaz

COPYRIGHT NOTICE! The inventor and author of the basic idea of this modification is Steve Chambers. The author is asking that the information about modification is not used by others for personal gain. Any individuals or companies wishing to produce commercial products based on the modifications shown on his website please contact him directly.

Also I took ideas from Martin Burri who has a very good application for the 4066 switch.

WARNING!: If you open the camera, you will void it's warranty. I cannot be help responsible if you damage your camera. You "mod" it at your own risk!

This mod among others has been referenced in Celestron's webpage Advanced user's tips.

In the picture below you see the camera as it comes from the box, there are two circuit boards, on the right side it's the SAA8116H, not shown as it's underneath the board.

On the left it´s the CCD board, here is were most of the work must be done. This mod does not need the lifting of pins of ICs or cutting the copper lines.


 

 

First step, prepare the CD-4066 cmos switch,(purchased in a electronic parts store) in this case I used a wire-wrap IC base (I used it when was in the University) and prepared an arrangement of 4 10K resistors with the wrapping wire.

After that passed the wires to the other side and soldered to the IC base pins.

The connection of the blue wires and resistors are as follows:

1 - All resistors have a common point to +5v (pin 14 of the CD-4066)

2 - Then solder a piece of wire-wrap cable to the other end of the resistors

3 - The loose ends must then be connected to the pins 2, 3, 5 and 13.

After some analisis I found that the connections between the SAA8116 and the Sony D1267 were via single wires, in this case they enter via the connectors on CCD board. The Ping 4 of the Sony chip is the orange wire on Connector 1 and the Pins 7 and 9 are on the brown wire on connector 2.

The next step is to fix the 4066, in this case the cables were moved and the chip was glued to the case.

 

Now the most delicate step, the cutting of the two wires and soldering to the 4066 base.

As you see the two cables that come from the CCD board go to pins 2 and 3 and the ones that come from the main board go to pin 1 and 4.

A more detailed picture can be seen here

On the previous picture you can see the power leads that go from the 4066 to the USB connector. the red cable goes to the red cable of the USB (+5V) and the black (GND) goes to the black cable on the USB cable. After soldering these cables, you may want to put some glue over them.

The external connector, the one that controls the LE mode form the PC, it´s a stereo mini plug.

The connections are:

4066 pin 13 to parallel pin 2

4066 Pin 5 to parallel pin 5

Power ground to parallel pin 21. It can be soldered to the black wire that connects both boards, see picture below

The control bits of the port are Data 0 and Data 3, you must adjust your capturing software to handle those pins.Note that this is the default setup for use with K3CCDtools software.

The full mod is ready to be tested.

This is the diagram based on Martin Burri diagram:

   

Now the testing....I have no equipment to test the long exposure as my telescope has no tracking possibility, however I tested the normal work (Planetary imaging) and it´s ok.

Serial Port Control: I had my laptop replaced with a new one that had no serial or parallel ports, so I had no way to control the LX Mode. Based on Steve´s web page I made my own "Serial to Parallel" converter, however, you need an USB to Serial convertor, so far, I have been able to test the Omega (made by prolific technology) and the Belkin F5U109 adapters. The diagram can be seen here

Jan 21st 2005: I was able to test the long exposure, it worked as expected with K3CCDTools and the default parallel port setup, for testing just focused Sirus and left the camera on for 10 seconds and voila! the star trail was there.

  The moon in normal mode Sirius 10 sec LX mode

Jan 30th 2005: I made my first ever Saturn Image in normal mode and M42 in long exposure mode

 

                           

Saturn 1/50 seg 242 Frames                            M42 2 x 3.5 seg Frames

 

 

An International Astronomical Imaging Group, Exploring the limits of Unconventional Imaging devices

Freddy Díaz This page was last modified on 21-Oct-2011