Ground Sphere CubeSat Ground Station

h1. Ground Sphere Prototype Assembly Instructions v0.1 (OUTDATED)

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h2. Introduction

Version 0.2 is the second prototype, which sacrifices some of the flexibility of v0.1 in order to move toward a more polished kit version of the ground station.  The overall design is the same between v0.1 and v0.2, but the details and several components have changed. Below are the assembly instructions for v0.2.

h2. Structural Component Pre-assembly

h3. Tools

* Hacksaw or chop saw

* Sharp knife

* Drill or drill press

* Ruler or caliper

* Pen or pencil

* Optional:  Centering jig for drill press

h3. Materials

* 1ea (ANT01) ¾” sched 40 PVC coupler

* 1 ea length of ¾” PVC sched 40 pipe 3” or longer.  Makes (ANT02) coupling sections

* 1ea (ANT05) ¾” PVC sched 40 to ½” NPT male adapter

* 1ea (ANT06) ¾” PVC sched 40 end cap

* PVC cement primer (purple solvent)

* PVC pipe cement

* Optional: PVC safe spray paint in a desirable color.

h3. Safety issues

* Care must be taken when working with powertools, sharp blades, or saws. 

* When using a chop saw, drill, or drill press, eye protection should be worn. 

* PVC solvent and cement must be used in well ventilated areas.

* Spray paint must be used in a well ventilated area, and should be done in a paint booth or outdoors.

h3. Product or Outcome

All plastic components for the Ground Sphere Mk2 upper structure.

h3. Procedure

# Using a chop saw or hack saw, cut 2 sections of ¾” PVC sched 40 pipe 1¼” long.

# Using a sharp knife debur the inside and outside of the sections.  

# These become coupling sections (ANT02).

# Using the PVC cement primer (purple solvent), lightly coat the whole outside of both coupling sections.

# Without dipping the applicator back into the primer, lightly coat the inside of the ¾” PVC sched 40 to ½” NPT male adapter. (ANT05).

# Without dipping the applicator back into the primer, lightly coat the inside of the ¾” PVC sched 40 end cap (ANT06).

# Lightly coat the inside of the unthreaded side of the ¾” PVC sched 40 to ½” NPT male adapter (ANT05) with PVC cement.

# Quickly insert one of the coupling sections (ANT02) and set aside to cure.

# Lightly coat the inside sides of the ¾” PVC sched 40 end cap (ANT06) with PVC cement.

# Quickly insert the remaining coupling section (ANT02) and set aside to cure.

# As accurately as possible drill a 3/16” hole in the exact center of the side on the ¾” sched 40 PVC coupler (ANT01).  The use of a drill press and centering jig is recommended.

# Rotating the part 180 degrees, drill a 3/16” hole in the exact center of the opposite side on the ¾” sched 40 PVC coupler (ANT01). 

# Rotating the part 90 degrees, drill a 3/16” hole in the exact center of the ¾” sched 40 PVC coupler (ANT01) between the first two holes.

# Rotating the part 180 degrees, drill a 3/16” hole in the exact center of the remaining side on the ¾” sched 40 PVC coupler (ANT01). 

# The holes should be at the 12 o’clock, 3 o’clock’ 6 o’clock, and 9 o’clock positions when sighting down the ¾” sched 40 PVC coupler (ANT01). 

# If it is desirable to paint the ground station components, this is a good time to do so.

# Set the units aside for integration with the antenna body.

h2. Assembling the Phasing Loop

h3. Tools

* Needle nose pliers

* Wire cutters

* Wire strippers

* X-acto knife

* Terminal crimper

* Ruler or caliper

* Dental pick or needle

h3. Materials

* 3ea (ANT10) Insulated crimp ring terminal Red (22-18 AWG) 

* 1ea (ANT11) Insulated crimp ring terminal Blue (16-14 AWG)

* 1ea (ANT13) Antenna line, SMA female connector to pigtail

* 1ea (ANT15) Tuned length of RG62u 90ohm coaxial cable

h3. Safety issues

* Care must be taken when working with hand tools, sharp blades, or sharp points.

* Coaxial cable wires, both the center conductor and shield wire can easily pierce the skin.

* Should a shield wire pierce the skin, remove it carefully since it can break off well below the surface of the skin, requiring painful removal

h3. Product or Outcome

All radio frequency (RF) components for the Ground Sphere Mk2 upper structure.

h3. Procedure

# Cut the RG62u 90ohm cable (ANT15) to precisely 2.775”.  

## Note:  the RG62u 90ohm cable (ANT15) should already be cut to length.  

# Verify the length.

# Using the X-acto knife, strip ¾” from each end of the RG62u segment (ANT15) and retain the insulation tube.  

## Note:  If something goes wrong with the RG62u segment (ANT15), do not cut off the messed up end and retry. It is a specific length and must remain so.  

# In the event of breakage, use another segment of the correct length.

# Using the dental pick or needle, gently unbraid the shield from both ends of the RG62u segment, twisting the strands into a single strand.

# Some breakage of the shield strands is unavoidable.  

# Remove any broken strands.

# Using the X-acto knife, strip ¼” of insulation from the center conductor from both ends of the RG62u segment (ANT15).  

# With the needle nose pliers, form a hook in the end of both of the center conductors as small as possible, a 1/32” across.

# Slip a red ring terminal (ANT10) over one of the center conductors.  The hook should just fit into the hole of the ring terminal (ANT10).

# Crimp the ring terminal (ANT10) with the crimper.

# Trim the insulation tubes removed from the RG62u segment (ANT15) in step 2 into ½”.

# Slip one of the ½” insulation tubes over the shield wires twisted in step 3 on the same side as the terminal we just terminated in step 7.

# Insert a red ring terminal (ANT10) over the exposed twisted shield wire insulated with the insulation tube in step 9.  

# Allow a small amount of play in the length (the insulation tube should not be tight)

# Crimp the ring terminal with the crimper

# Cut the antenna line (ANT13) at six inches from the end of the connector and strain relief.

# Use the wire strippers at the 14ga setting and gently strip ¾” from the antenna line ( ANT13) and retain the insulation tube.

# Using the dental pick or needle, gently unbraid the shield from the stripped end of the antenna line (ANT13), twisting them into a single strand.

# Some breakage of the shield strands is unavoidable.  

# Remove any broken strands.

# Using the X-acto knife, very carefully strip ¼” of insulation from the exposed center conductor on the antenna line (ANT13).

## Note:  If something goes wrong with the antenna line (ANT13), you may cut off the messed up end and retry, beginning at step 11.

# There is enough extra to correct one mistake in this manner.

# In the event of a second mistake on the same antenna line, discard the shortened antenna line and use another beginning at step 10.

# Slide the remaining ½” insulation tube over the remaining shield wires of the RG62u (ANT15) segment twisted in step 3.

# Trim the insulation tube removed from the antenna line (ANT13) to a length of ½”

# Carefully slide the insulation tube over the shield strands of the antenna line (ANT13) twisted together in step 12.

# Insert a blue ring terminal (ANT11) over the exposed twisted shield wires on both the antenna line (ANT13) and the RG62u segment (ANT15) insulated with the insulation tubes in steps 14 and 16.  

# Allow a small amount of play in the length (the insulation tube should not be tight)

# Crimp the ring terminal with the crimper

# Insert a red ring terminal (ANT10) over both of the remaining exposed center conductors, on the antenna line (ANT13) and the RG62u segment (ANT15) and crimp the ring terminal tightly.

# Set the unit aside for integration with the ground plane and antenna body

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