IMT3b – Build Part IV

1st January 2021

So the cable is installed in the trench visible here before I laid the ethernet.

Power cable

It runs all the way across the garden to the observatory very neatly.

Power cable across the lawn

When it reaches the observatory, enough cable is left to feed through there pipe later and the end is terminated in an outside socket. This will be later daisy chained to several internal plug to the observatory and the outside power fixed to a new brick pier that I will build.

Observatory end

The next job was running the ethernet from the house. I purchased Cat6E as I also wanted to run cable to several places around the house that would require PoE (Power over Ethernet) which allows one to fix an access point without the need for an additional power supply. I started by preparing one end of the cable to be spliced and crimped given I had not done this for a few decades. I purchased the crimping and test equipment online and it seems to have worked well.

Cat6E prep

Then I laid out the wires in the correct colour format. The tricky part is getting all the wires to stay flat after twisting round each other to get them in the right order. Then to make matters worse you cut them short to much the connector on and the cables self align in slots.

Cat6e Wiring Diagram - Train Wiring Diagram -

The final end looks like this.

Crimped Cat6E

Out of interest I have posted here the access point I purchased that is PoE, I simply love it, although nothing to do with the observatory per say apart from going into the kitchen in this instance at the same time as running the cable to the observatory.


The AP does require a switch or hub or router that supports PoE, unfortunately none of the hubs that come from the major broadband suppliers ship any so I purchased the TP-Link switch that does.

TP-Link PoE switch

To conclude this part here is the single Cat6E cable going into the AP.

Back of access point

So then I set about running the cable from the observatory site across the garden with an RJ45 connector ready and waiting under the tarpaulin at the vegetable patch.

Ethernet CAT6E cable installed long with power.

I then terminated the first leg of the cables journey in the woodshed where the power is connected (I plane to spur a connection to the planned Summerhouse from here in the Spring) and setup my laptop in the vegetable patch to test the connection which worked!

Testing the connection

Before I get to the final piece of ethernet running from the woodshed to the workshop, I wanted to run the large length of cable from the workshop to the Snug. I am fortunate that a BT cable had been run back in the 90’s to the workshop when it was used as a business office. Given I had no need for a landline in the workshop I decided to use the BT cable to pull through the ethernet down the length of the underground pipe between the workshop and the house, again I am very lucky it was there!

Old BT cable and duct comes in handy 🙂

I started to feed the cable through along with a new piece of rope I found in another duct! But I quickly found a break in the pipe located under the steps leading into the workshop.

Duct broken just outside 🙁

After hours of pulling and pulling back the other way, then more pulling, my daughters boyfriend Luke (small mercies for Lockdown he currently lives with us) retrieves the ethernet cable taped to the BT cable some 100ft away.

Ethernet comes through 🙂

This is the BT connection rats nest at the back of the house who’s cable I repurposed then removed, next to a bunch of electric connection boxes for outside stuff!

The saga for ethernet does not stop there, but nearly! We pulled through the rest of the cable and tacked it up the wall on the right and then along to the door where we spend hours drilling and hunting for the cable in the loft………..

Cable ready to go into the house

Darkness falls as we finally pull the cable through into the house and into the Snug.

Ethernet cable into the loft and the house.

Here is the tight loft space where the cable runs through.

Loft eaves and ethernet cable

The final leg was dropping the cable into the Snug where the fibre terminates in the house from the loft. It snakes it’s way around the perimeter of the house inside the loft (I have a chalet bungalow) which took about 2 hours!

Main ethernet connection to observatory!

Fortunately I have the most understanding wife in the world who is very supportive to have her husband spend hours in the loft with a cable.

IMT3b – Build Part III

22nd December 2020

So with the site prepared I had one last check of the levels as the ground slopes away to the right thus meaning I needed to adjust the former for the central block. The dome segments can be seen resting in the background. I also used a large bag of stones to hold the former in place.

Slopping site

Next I cut a hole in the former for the pipework that will take the electric cable and ethernet from the house. I used some old downpipes and kitchen waste pipe I found lying around in the garden.

Pipework for cables

Here is a closer shot of the pipework that shows a 90 degree angle that all be flush with the finished floor.

Closeup of pipes

Now I had to prepare a trench for the cable running from the observatory to one of the sheds across the garden. So GingerGeek and I set about digging 6″ down where the cables would lay, eventually to be covered by a slabbed path. The digging took hours, hitting rubble including glass in the ground and offending chunks of flint.

About 70 feet trench across part of the garden

Down to the left as the ground slopes away and towards the observatory location, we dug the trench round the corner. The cable would have to run under large rotes and as we found out a large sleeper buried in the ground across the opening to the vegetable patch.

Entrance to observatory area

Turning around standing with your back to the vegetable patch where the observatory will be sited, you can see the trench running off towards some outbuildings/sheds and a planted area that I would have to tackle next as GingerGeek had to go do some chores at home.

Planting area to be dug through!

So it took almost as much time digging this section out as it did getting across the expanse of lawn. Routes from the Sycamore (left) and countless plants made this hard work. I then managed to get to the trellis separating the planting from the 3 sheds on this side of the garden, which I would need to go under.

Trench within boarder

Around the other side of the trellis it was very cosy to work in the tight space, old wood still awaiting collection by the previous owner meant digging was difficult, also the land raises up quite a bit this side so I had to dig the trench deeper. The hole I managed to create is shown by the red arrow. Again lots of building rubble had to be removed and I landed up on my hands and knees in the trench digging with a trowel.

Hole to the other side!

So I had made it to the shed. Now it was dark and I had to wait another month before Steve the electrician would be able to fit me in. When he arrived and the armoured cable was laid and fed under all the roots, he made the connection in the existing fusebox in the shed.

Observatory connection left.

Then it ran down the wall and out through a hole that was serving the existing power feed from the workshop. The woodshed is in a dire state and needs replacing, but will serve as a hub for equipment until such time I get around to it.

Cable out of the very unloved woodshed.

Next I will share where the power and ethernet cable runs and how I installed.

Viewing Report 7th May 2020 – IMT3

20:01 – 01:00

Opened dome early switching the safety for the brightness on the new AAG. The first thing to do tonight was to calibrate a little but more the infrared sensor which informs the cloud coverage. This was suggesting it was Cloudy, borderline Overcast and given it was very clear with a hint at wisps of cloud I adjusted the couple of figures for the sensor, from -17 for Clear to -14 and from -14 for Cloudy to -12.

I then set about taping up the USB and power for the SX camera on the Esprit. This is because the connectors supplied are clearly not in tolerance as I have tried many cables and they call fall out. The tape should suffice for the moment and now the camera reconnects to the NUC computer running SGPro.

Tape for USB cable

GingerGeek and I started to have a look at the sky around 9pm. The sky was not totally clear with some wisps of cloud. We tried to get to a point where we could test guiding the 12″ through the Esprit, however as ever the clouds rolled in. However, during setting up the SX814 camera on the Esprit as the guider and performing a darks calibration run we got an error on the USB bus again (we get lots of USB errors) which not only kicked out the SX814 but also the AAG weather station. The problem was it almost killed the AAG software and we had to cancel the process running to resolve. This meant we lost all the settings in the AAG so we have tried to rebuild as per the new screen shots below.

AAG Weather Station New Settings

So instead we re-ran the Flats Calibration Wizard for the OS with the camera set to Gain 139 Offset 21 and also another run at Gain 75 Offset 12. The reason for re-running is that I suspect the flats we have are ever so slightly over exposed at 30-32k rather I prefer them to be at 22-23k.

We also created 2 new profiles that were simply named so we can see them in the list and simplify the naming convention and amount of profiles needed. We will choose the guider on the night within one of the two profiles created. We will also look to review and simply the other profiles for the two additional OTAs tomorrow and delete the remains profiles given the large number we now have.

Two new simpler profiles at the bottom