Old Precision C120 Ku Feed

[Channel Hopper]

The old red Precision feed with the recessed central scalar was used on a Precision dish for satellite reception. It was part of a setup that used a KHM-36RL motor and a Ku band LNB. The KHM-36RL motor had the strange declination adjustment that used a pipe fitted at a non vertical angle to a circular steel plate. Rotation of the plate adjusted the declination angle, pics attached.


Rgds

Rotational declination adjustment has been used for years on larger dishes, Orbitron and I think KTI made use of it on their range of 8 -12 foot antennas.
Putting antennas together as a system with the H-H mounts for satellite use does not exclude them from originally being sourced in a job lot, from a company that had surplus to their original design role.

 

[moonbase]

Rotational declination adjustment has been used for years on larger dishes, Orbitron and I think KTI made use of it on their range of 8 -12 foot antennas.
Putting antennas together as a system with the H-H mounts for satellite use does not exclude them from originally being sourced in a job lot, from a company that had surplus to their original design role.

CH,

Yes, I agree, the red C120 feed with the recessed inner scalar could have originated as a non satellite feed and become paired up with a satellite dish at a later date. One of the reasons for my post was to find out if anyone else had seen such a feed for a Precision dish. The red colour could have been a colour code to possibly indicate that it was originally manufactured for non satellite use? The other Precision C120 Ku feeds I have seen are either the anodised black colour or a silver grey colour, this is the first time I have seen a red one.


Rgds

 

[Channel Hopper]

I do have a couple of gold anodised Precison feeds, these were supplied with Chaparral polariser equipment.

 

[Channel Hopper]

CH,

Yes, I agree, the red C120 feed with the recessed inner scalar could have originated as a non satellite feed and become paired up with a satellite dish at a later date. One of the reasons for my post was to find out if anyone else had seen such a feed for a Precision dish. The red colour could have been a colour code to possibly indicate that it was originally manufactured for non satellite use? The other Precision C120 Ku feeds I have seen are either the anodised black colour or a silver grey colour, this is the first time I have seen a red one.


Rgds

Have you checked the internal diameter of the feed to see if there is a variation ?

 

[moonbase]

Have you checked the internal diameter of the feed to see if there is a variation ?

CH,

Good point, no I have not checked it yet. I will dig out my vernier caliper and go and have a measure, back shortly.

Rgds

 

[moonbase]

Measurements as listed below:

Red Feed - inner diameter of central scalar = 21.9mm, inner diameter of waveguide at other end = 18.9mm
Black Feed - inner diameter of central scalar = 21.95mm, inner diameter of waveguide at other end = 18.95mm

They are practically identical, the red feed is a little corroded in parts but I tried to make sure I got measurments across a clean surface.


Rgds

 

[Channel Hopper]

The red feed may be tuned for a slightly higher frequency then, or originally advertised/peddled as a true wide band feed, including the telecom (12.5-12.75 GHz) band

 

[blademedia]

What size aluminium centre focus dish do you think these motors would be OK with

Problem is the pole cap is small, if you was to make an adaptor to a bigger pole I cant see no issue with a 1,8, quite sure it would move it happily and safely

 

[blademedia]

The red feed may be tuned for a slightly higher frequency then, or originally advertised/peddled as a true wide band feed, including the telecom (12.5-12.75 GHz) band

Now that's a good suggestion

 

[John]

The Filmnet one was better.....

....You dirty-old-man, as Harold used to say.

 

[moonbase]

Problem is the pole cap is small, if you was to make an adaptor to a bigger pole I cant see no issue with a 1,8, quite sure it would move it happily and safely

blademedia,

Thank you for your reply.

I have a pole cap adapter that I recently got fabricated, it adapts a 4.5" king post to fit a 3" pole cap motor, picture attached.


Rgds

 

[blademedia]

blademedia,

Thank you for your reply.

I have a pole cap adapter that I recently got fabricated, it adapts a 4.5" king post to fit a 3" pole cap motor, picture attached.


Rgds

That's a nice well made adaptor moonbase,

 

[moonbase]

That's a nice well made adaptor moonbase,

blademdia,

Thanks, I bought the two sections of steel pipe from eBay and got them delivered directly to the fabricator. I also emailed a specification drawing for the fabricator to work from. A few days later I got the call to come and collect it, picked it up, gave it a wipe down with solvent then applied some primer/undercoat/top coat... job done.

Rgds

 

[blademedia]

blademdia,

Thanks, I bought the two sections of steel pipe from eBay and got them delivered directly to the fabricator. I also emailed a specification drawing for the fabricator to work from. A few days later I got the call to come and collect it, picked it up, gave it a wipe down with solvent then applied some primer/undercoat/top coat... job done.

Rgds

I saw your post in another thread moonbase you did right, them from SSS are useless and £200 for the cheap one, probably made in China and only fit for hanging washing on them, what did you say £35 for fabrication and a few £ for parts, quality job that will last for years.

 

[RimaNTSS]

Sure, it is professionally fabricated. Welds are perfect. And device will do the job. Seems that there is enough space between an adapter and the main pipe to get adapter plumb (in case if main pipe is not vertical).