Jump to content




HEQ5 Rajiva Upgrade - Part 1 (Long, with pics)


Recommended Posts

This upgrade was easy. No, really, very easy!! To recap, it consists of replacing the main chip in the mount with a daughter board on which is a new chip with added functionality - GOTO, Intelli-Track, PEC, etc. I also bought a new set of gears as well, but that will be a part two!!

This part required the removal of the chip from the hand controller, as well as the main chip in the mount. I started with the hand controller.

1) Remove the 4 screws on the top of the controller

2) Remove the lid - this required a bit of force as the buttons come off as well - they are the press-click type mounting


3) Undo the two screws holding the top PCB in place, bend this forwards out of the way


4) Undo the 4 small PCB screws and remove the PCB from the controller


5) Using a thin knife, carefully work the IC loose and remove - noting which side the dimple is

6) Insert the new IC, careful to align the dimple to the correct side


7) Re-assemble is the reverse of disassembly

Job done!

Next, the mount.


1) Undo the screws holding the motor cover in place, and remove motor cover

2) Undo the 4 screws that hold the mount cover in place (2 are under the motor cover)


3) Undo the 2 allen bolts retaining the smaller gear wheels and remove the gears - don't need to remove the larger ones

4) Undo the 4 motor retaining screws from each motor

5) Remove both motors, carefully note which is which!!


6) With a long screwdriver, remove the two PCB retaining screws

7) Unplug the three cables from the PCB and carefully remove the PCB


8 ) On the anti-static pad, with the thin knife, remove the IC

9) There are two capacitors at each end of the IC socket - these need CAREFULLY bending down so that the new board sits properly

10) Insert new board into the IC socket, again, being careful of orientation


11) Reassemble


I had already installed the software recommended for use with the upgrade, but you could, if you really wanted, do everything from the command line. I connected my USB-SERIAL converter, connected the lead from that to the 15-pin D-Sub socket on the mount, powered up the mouunt and hit the Connect button.

Nothing. Nada. Zilch. Panic!

I checked everything, and then realised I had not set the correct comms port in the software. Waiting for a moment for my heart rate to stabilise, I connected again!

Eureka!! Success!! I then set up the mount with the default settings, guide speed, goto speed (40x), goto licence number, intellitrack licence number, saved everything and power cycled the mount.

I connected again and thought OK, time for a test. I set the coordinates to Dubhe, synchrionised the mount and software (so it knows where it is pointing) and then told it goto M108. And off it jolly well went!! It gives you an estimated time to reach the goto point, and it was fairly accurate. Of course, this was tested with no scope and load, so I don't know how accurate the positioning is going to be - although other users seem to be very happy with it, so I imagine it will be fine. One thing I didn't check (and I will tonight) is if it reads the mount position if I manually move it.

So, it works!! And what's more it was easy! Very easy! If only all mods where that easy :) :)

Part 2 (the gears and adjustments) will follow in the new year!


Link to comment
Share on other sites

Phil - This guy http://ozastro.dyndns.org/ is a guru of the HEQ5. Everything you need and more is on here! He is in the process of designing a break-out box to split the functionality of the 15-pin socket from RS232, ST4, DSLR Cable release, motor focuser, etc.

Gordon - It was around £170 in total, and that included 2 Conrad motors (for the 100:1 gears), the hand control update, MCU update, RS232 lead, GOTO licence, IntellyTrack licence and delivery. And yes, the downside is that you need to use a laptop for the goto functionality. You can also use a PDA, but I don't know which ones as yet.

IntellyTrack is a function that adjusts both RA and DEC if you are tracking, say, a comet.

Link to comment
Share on other sites

Well, last night I cut the hole for the 15-pin socket, and re-assembled that fine polar illuminator from Jaffa ( :) ) and checked everything still worked. It did!

And of course, it won't read the mount when I move it manually, I don't know why I thought it would! The consensus with other upgraders when moving to another part of the sky is to move manually, resynch with a new object and then use the GOTO. Makes sense.

I'm now starting on a break-out box that will velcro on the side of the mount to split the RS232, ST4 guide port, DSLR Remote Release socket, mount power and my dew heaters all into the one. It will mean I only have one lead from the lappy to the mount, and all the connections are in one place :)

All I need now is some clear fog-free cloud-free skies!! Some hope, eh? :lol:

Link to comment
Share on other sites

  • 3 weeks later...

Daz, Great piece of work very well documented! I wonder if you have started to tackle the Conrad gearbox upgrade as I would like to do this mod on my non go-to EQ6 to try and eliminate the arc second motor vibration it sometimes displays.



Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.