Author: WebMistress

[et_pb_section bb_built="1"][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.9"]

Introduction:

Dew heaters warm the optics of a telescope to prevent dew forming. Commercial control units and heater elements are available, however with a couple of hours, a soldering iron and a few tools, the control units and heaters can easily be constructed at home. As well as being a satisfying experience building astronomical accessories building these is also financially viable with a controller and as many heating elements as you need costing the price of a mid to low range control unit.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_2"][et_pb_text admin_label="control unit Text" _builder_version="3.9"]

Control Unit

The control unit provides the ability to alter the amount of heat passing through the heater bands and the most efficient method is to switch the power to the heater elements on and off using a DC to pulse width converter, this varies the time the power is applied to change the average power to the heater bands. Fortunately, DC to pulse width converter circuits are available as simple kits from Velleman so do not require any electronics knowledge. The K8004 kit is specifically designed for the control of heaters, motors and lights and has short circuit protection and a maximum load of 6.5A - plenty for our purposes, this kit is about £13 (2010)

[/et_pb_text][/et_pb_column][et_pb_column type="1_2"][et_pb_text admin_label="graph" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_2"][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_2"][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.9"]

Heater Elements

Heater elements are made by passing a current through a resistive wire, the more current the more heat produced and the overall power can be calculated using Ohm’s law, Volts = Current x Resistance and Power = Current squared x Resistance.

Resistance wire is usually measured in Ohms per meter, and our heater bands have to be a specific length dictated by the overall circumference of the object the heater has to go around, although by looping the wire or connecting in parallel it is usually possible to get the correct length of wire for the power desired.

[/et_pb_text][et_pb_text _builder_version="3.9"]

The simplest way to enclose the heater elements is to sow them onto floor foam, the type used on kitchen floors is ideal, this provides some substance to your heater bands and insulates them on the outside, I cut mine 100mm longer than the element to provide enough space to sow the lead on ensuring no force is put on the soldered connections.
The element is then encased in a sleeve of hook and loop fabric.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_2"][et_pb_text _builder_version="3.9"]

Cable sown onto element for high strength

[/et_pb_text][/et_pb_column][et_pb_column type="1_2"][et_pb_text _builder_version="3.9"]

Heater element sown into foam, as much as possible is kept on the side that will touch the telescope

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.9"]

Some commercial dew bands suffer from low quality, short leads and/or low quality connectors so don't scrimp here, High quality cable (road cable) and connectors will only cost a few pounds but really make your dew bands look superior to commercial equivalents.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_2"][et_pb_text admin_label="Image" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_2"][et_pb_code _builder_version="3.9"]<div style="position:relative;height:0;padding-bottom:80.94%"><iframe src="https://www.youtube.com/embed/tYTMBRGmQUc?ecver=2" style="position:absolute;width:100%;height:100%;left:0" width="445" height="360" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></div>[/et_pb_code][/et_pb_column][/et_pb_row][/et_pb_section]

[et_pb_section fb_built="1" _builder_version="3.22"][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat"][et_pb_column type="4_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="Intro text" _builder_version="3.27.4"]

Noctilucent clouds are phenomena seen during the summer twilight (June and July for the northern hemisphere and December and January for the southern). It is caused by sunlight striking stratus clouds at a height of around 82km.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat"][et_pb_column type="4_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="Honor title text" _builder_version="3.27.4"]

Honor Wheeler's Images

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat" column_structure="1_4,1_4,1_4,1_4"][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="3.27.4"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="3.27.4"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][/et_pb_column][/et_pb_row][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat"][et_pb_column type="4_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text _builder_version="3.27.4" z_index_tablet="500"]

"I was holidaying in Kelling and had the very good luck of seeing Noctilucent Clouds on the last night I was there. 

Below are some images I managed to snap. I must admit that the clouds were so extensive that I didn't think they were NLC's! I was not prepared either, the only lens I had on me was a 70 - 300 lens which didn't do the scale of the clouds justice. "

Honor

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat" column_structure="1_4,1_4,1_4,1_4"][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="NLC Image" _builder_version="3.27.4" z_index_tablet="500"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="NLC Image" _builder_version="3.27.4" z_index_tablet="500"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="NLC Image" _builder_version="3.27.4" z_index_tablet="500"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][/et_pb_column][/et_pb_row][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat"][et_pb_column type="4_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="Simon title text" _builder_version="3.27.4"]

Simon Dawes' Images

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat" column_structure="1_4,1_4,1_4,1_4"][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="3.27.4"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="3.27.4"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="3.27.4"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="3.27.4"]

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat"][et_pb_column type="4_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_code admin_label="SD Youtube"]

[/et_pb_code][/et_pb_column][/et_pb_row][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat"][et_pb_column type="4_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="Martin crow title text" _builder_version="3.27.4"]

Martin Crow's Images

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat" column_structure="1_4,1_4,1_4,1_4"][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="3.27.4"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="3.27.4"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" custom_padding__hover="|||"][/et_pb_column][/et_pb_row][et_pb_row _builder_version="4.7.7" _module_preset="default"][et_pb_column _builder_version="4.7.7" _module_preset="default" type="4_4"][et_pb_text admin_label="Images by Jim Burchell" _builder_version="3.27.4" saved_tabs="all" global_module="3222"]

Images by Jim Burchell

[/et_pb_text][et_pb_text _builder_version="4.7.7" _module_preset="default" hover_enabled="0" sticky_enabled="0"]

[caption id="" align="aligncenter" width="600"] Image by Jim Burchell A collage of NLC'S taken last year on the 12/07/20 Pentax K70 31mm f6.3 10 sec iso 400.[/caption]

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

[et_pb_section bb_built="1"][et_pb_row][et_pb_column type="4_4"][et_pb_text admin_label="multi Text" _builder_version="3.9"]

If you are observant you will occasionally be rewarded with multiple phenomena in the sky as these images by members show.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="4_4"][et_pb_text admin_label="Martin Crow's Images Title" _builder_version="3.9"]

Martin Crow's Images

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_2"][et_pb_text admin_label="Martin Image 1" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_2"][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="4_4"][et_pb_text admin_label="Honor Wheeler's Images Title" _builder_version="3.9"]

Honor Wheeler's Images

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="4_4"][et_pb_text admin_label="Honor Wheeler APOD text" _builder_version="3.9"]

Atmospheric Optic Picture of the Day

Our very own Honor Wheeler makes Optics Picture of the Day (20/03/2010) at the world renowned site for extra special atmospheric optics. “I live in Kent, in the Southeast of England and so don't usually expect complexity in a halo display as the conditions are never quit right. Today, however, I was amazed and excited to photograph sundogs, a partial 22deg halo, an upper tangent arc, a Parry arc, circumzenithal arc and a partial supralateral arc. I've photographed all but the supralateral arc separately before but never all together! These photos were taken between 15.34 and 15.41UT but overall the display lasted for approx 20 minutes with the circumzenithal arc lasting the longest.”

If you have HaloSim installed, run the simulation yourself after downloading the simulation file kent.sim

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_2"][et_pb_text admin_label="Honor Image #1" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_2"][et_pb_text admin_label="Homor Wheeler Image #1 Simulation" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

[et_pb_section fb_built="1" _builder_version="4.16" global_colors_info="{}"][et_pb_row _builder_version="4.16" background_size="initial" background_position="top_left" background_repeat="repeat" global_colors_info="{}"][et_pb_column type="4_4" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text _builder_version="4.16" global_colors_info="{}"]

Brian's observatory is a modified, prefabricated shed, with a novel 'lift off' roof design.

The advantage of this approach is a simple to construct observatory that will look like a normal shed in the garden and thus not attract too much attention or be out of keeping in Brian's garden.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="4.16" background_size="initial" background_position="top_left" background_repeat="repeat" global_colors_info="{}" column_structure="1_2,1_2"][et_pb_column type="1_2" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="4.16" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_2" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="4.16" global_colors_info="{}"]

Room is tight so a small unobtrusive observatory was called for.
Location was dictated by available space.

The Observatory has space for a laptop station, cupboard and chair.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="4.16" background_size="initial" background_position="top_left" background_repeat="repeat" global_colors_info="{}"][et_pb_column type="4_4" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text _builder_version="4.16" global_colors_info="{}"]

The roof is held on with 'up-and-over' catches at the points the original shed would have had permanent fixings, making the roof fast to remove, but still secure in the wind.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="4.16" background_size="initial" background_position="top_left" background_repeat="repeat" global_colors_info="{}" column_structure="1_3,1_3,1_3"][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="4.16" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="4.16" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text _builder_version="4.16" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="4.16" background_size="initial" background_position="top_left" background_repeat="repeat" global_colors_info="{}" column_structure="1_3,1_3,1_3"][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="4.16" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="text" _builder_version="4.16" global_colors_info="{}"]

A bathroom rail is used to make a handle for the roof panel so it can be easily manoeuvred

[/et_pb_text][/et_pb_column][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][/et_pb_column][/et_pb_row][et_pb_row _builder_version="4.16" background_size="initial" background_position="top_left" background_repeat="repeat" global_colors_info="{}"][et_pb_column type="4_4" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text _builder_version="4.16" global_colors_info="{}"]

The roof is removed in two sections, then the central bar at the apex of the roof is removed.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="4.16" background_size="initial" background_position="top_left" background_repeat="repeat" global_colors_info="{}" column_structure="1_3,1_3,1_3"][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="4.16" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="4.16" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text _builder_version="4.16" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version="4.16" background_size="initial" background_position="top_left" background_repeat="repeat" global_colors_info="{}" column_structure="1_3,1_3,1_3"][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="4.16" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="image" _builder_version="4.16" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_3" _builder_version="4.16" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text _builder_version="4.16" global_colors_info="{}"]

Obviously this design doesn't allow access to the horizon, but neither did Brian's garden, the observatory doesn't obstruct the sky that is available from this site.

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

[et_pb_section bb_built="1"][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.9"]

The Frankenscope

I needed a portable telescope to take to places such as Kelling Heath. My main telescope is stuck in its observatory. It needs to allow me to do imaging as well as visual observations. The solution was to be build Frankenscope!

What do you need to build Frankenscope?

• LX200 tripod
• A Julian Tworek home-made wedge
• A 10” LX200 fork mount without the OTA
• An ETX 90mm Maksutov-Cassegrain telescope
• A finderscope
• An SBIG CCD camera
• Some steel stud, aluminium square tube
• And nuts! (you have to be slightly nuts to build this thing!)

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_2"][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_2"][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

[et_pb_section fb_built="1" _builder_version="3.22" global_colors_info="{}"][et_pb_row _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat" global_colors_info="{}"][et_pb_column type="4_4" _builder_version="3.25" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text _builder_version="3.27.4" global_colors_info="{}"]

The summer BBQ was a great hit again. About 25 members attended and we had food for about 100! The day was very relaxed. We had a few glimpses of the Sun through our Dobsonian telescope, Anita using Baader Solar Safety Film, unfortunately there were no Sun spots visible.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row column_structure="1_4,1_4,1_4,1_4" _builder_version="3.25" background_size="initial" background_position="top_left" background_repeat="repeat" global_colors_info="{}"][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text admin_label="Image" _builder_version="3.27.4" global_colors_info="{}"]

[/et_pb_text][et_pb_text _builder_version="3.27.4" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text _builder_version="3.27.4" global_colors_info="{}"]

[/et_pb_text][et_pb_text _builder_version="3.27.4" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text _builder_version="3.27.4" global_colors_info="{}"]

[/et_pb_text][et_pb_text _builder_version="3.27.4" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_4" _builder_version="3.25" custom_padding="|||" global_colors_info="{}" custom_padding__hover="|||"][et_pb_text _builder_version="3.27.4" global_colors_info="{}"]

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

[et_pb_section bb_built="1"][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.9"]

The Society and its members possess a notable range of astronomical equipment, much of it home made. A number of the these instruments have been constructed by John Wall who is internationally known as a telescope maker and is the inventor of the 'Crayford Eyepiece Mount' which has found favour all over the world.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_3"][et_pb_text admin_label="image" _builder_version="3.9"]

32" telescope designed and built by John Wall

[/et_pb_text][/et_pb_column][et_pb_column type="1_3"][et_pb_text admin_label="image" _builder_version="3.9"]

24" telescope designed and built by John Wall

[/et_pb_text][/et_pb_column][et_pb_column type="1_3"][et_pb_text admin_label="image" _builder_version="3.9"]

42" telescope designed and built by John Wall

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

[et_pb_section bb_built="1"][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.9"]

Variable Barlow Adapter for a Webcam

Changing the distance of an eyepiece or other sensor such as a webcam or DSLR changes the effective power (magnification) Andy Barber has made such a set-up for planetary imaging with a Phillips Toucam.

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_3"][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_3"][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][et_pb_column type="1_3"][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_3"][et_pb_text _builder_version="3.9"]

The effective focal length achieved will depend on the Barlow used and the distance from the Barlow to the imaging surface. These are calculated and displayed in the following graph.
 

[/et_pb_text][/et_pb_column][et_pb_column type="2_3"][et_pb_text admin_label="image" _builder_version="3.9"]

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_2"][et_pb_text admin_label="image" _builder_version="3.9"]

Andy's set-up including the box that protects the Laptop from the damp.

[/et_pb_text][/et_pb_column][et_pb_column type="1_2"][et_pb_text admin_label="image" _builder_version="3.9"]

Image of Jupiter taken with a variable Barlow and Philips ToUcam in 2010

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

[et_pb_section bb_built="1"][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.9"]

ATM Finderscope

A finderscope is an essential accessory for your telescope, if you don’t have one, or your finderscope uses an objective less than 50mm in diameter you might consider making one, this is a satisfying accessory to make and doesn’t require any real skill or optical knowledge.

I had a spare pair of binoculars that were out of collimation so of no real use, so I turned the objectives into a finderscope, the first I reused the objective and the focusable binocular eyepiece to make a ‘straight through’ finder with a 10x magnification and the second (shown here) used a broken star diagonal I was given (repaired but only for small loads) and the binocular objective.

The tube is made from a kitchen waste pipe and covered with as astronomical image from Hubble to make it look nice!

[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row][et_pb_column type="1_2"][et_pb_text admin_label="image" _builder_version="3.9"]

Completed Finder

[/et_pb_text][/et_pb_column][et_pb_column type="1_2"][et_pb_text admin_label="image" _builder_version="3.9"]

With mount and covering

[/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]

[et_pb_section bb_built="1"][et_pb_row][et_pb_column type="4_4"][et_pb_text _builder_version="3.9"]

A Battery Free Electric Focuser

Building an electric control for your focuser can help you achieve focus easier & quicker. With an electric control focuser, there is no need to touch the telescope and so you don't induce telescope wobble, which in turn, speeds up the task of focusing. You can buy electric focusers but they are expensive and can be difficult to mount (especially on refractors). This simple idea, is neat, easy to implement with parts bought from Maplin's and despite being an electric focuser, it doesn't use batteries!!!!!!

[/et_pb_text][et_pb_code _builder_version="3.9"]<div style="position:relative;height:0;padding-bottom:80.94%"><iframe src="https://www.youtube.com/embed/l1RHiFwV9Rk?ecver=2" style="position:absolute;width:100%;height:100%;left:0" width="445" height="360" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe></div>[/et_pb_code][/et_pb_column][/et_pb_row][/et_pb_section]