Feedline EME

In this page I would like to show you the type of feederline I think of to use to the 4-bay array that is meant for EME. The here shown coax is 7/8'' and is very cheap purchased from a former GSM tower refurbishment action.
Normally these cables come with the connectors inclusive, however not in my case. After visiting some fleamarkets I was happy to find some cheap connector that would fit my need. In these picture I show how such connectors are mounted. It is not a how-to-do session, more a foto series what I did.
First I needed to cut a piece of the cable that was used in the GSM tower to connect the outer conductor to earth. This is mandatory for lightning protection. The place were the outer is connected to a piece of smaller (...) copperwire is covered in thick sealand tape that is sticky and not nice to keep.

Here a detailed picture of the piece that is covered in tape...

After cutting the no longer needed piece, the coax cable reviels its qualty; Nice thick inner and outer conducor. The inner conductor of this type of 7/8" coax is hollow, it saves a lot of copper and weight (and costs).

Here I am busy on mounting a connector to the cable. The outer conductor has 'rings' and it is important to cut the outer conductor in exactly the right location. When doing OK, the mounting force of the connectorparts hold the coax in place.
In my situation, the cut must be at exactly to top if one of the rings in the outer conductor.

The centre pin of the connector is simply screwed into the inner conductor. No soldering involved like in mounting a connector to Ecoflex-15.
I use a inbus tool that has the right size to fit the sidehole of the centre pin....

Now the connector can be screwed to the part that was already over the cable.
It is quite difficult to find these large tools to clamp the pieces...

Is it all OK? Here a Spectrum-Analyser with tracking functions shows the rf-range from 0 - 3.6GHz. A nice sloping attenuation builds up as the frequency increases. Looks fine.

In the below table the results are written, very usefull results...especially for 144Mhz and 432MHz.