Flat coax performance

[aceb]

Has anyone used one of those short flat coaxial cable sections and gauged how lossy they are? We want to get DAB in the office but it's going to need an antenna on the flat roof, drilling holes through walls or windows frames is a no go so I thought I could try some flat coax through the window.

I guess they're normally used on high gain signals coming down from a dish rather than VHF so some loss will probably go unnoticed on satellite. I'm going to order one anyway but thought I'd throw it out to the forum for comments.

 

[Channel Hopper]

DAB is unlikely to be affected to the point it gets problematic.

Use aircored and just shut it in the frame, best place is actually behind the hinge as opposed to the lock/handles.

 

[Analoguesat]

It should work ok - I use a cheap flat coax on my 1090 aircraft tracking feed to get it through the window - the amp is next to the computer & I get 200+ miles in several directions

 

[Terryl]

Most show an 18 dB return loss at 2150 MHz, make sure it's rated for satellite signals and not just for TV.

What I do is to make an under the window or on the side of the window pass-through out of aluminum, wood or plastic, then using a "F" barrel connector you drill a hole through the pass -through and use this for the barrel connector, or just pass the coax through it before you put the "F" connectors on, then you can use standard coax.

This also depends on the type of window frame, and how you need to secure the window.

 

[aceb]

Thanks for the comments, our offices are fairly secure with all the windows alarmed using magnetic switches with very little tolerance, there's also three of them operated by a single remote handle so it's not just a case of tugging it shut. I doubt our facilities management company would appreciate me drilling through the frame to put any form of pass through in but it's a nice idea

I'm hoping that a 5 ele beam discretely mounted on the flat roof will get the London MUXs from Wrotham to give us a good choice of stations. The radio is going to be one of these https://www.amazon.co.uk/gp/product/B074KY6XG1

 

[jeallen01]

@Terryl

FYI, In the UK, DAB/DAB+ works in the 220-230 MHz range - so far less loss than at sat frequencies, and that's why you can take more "liberties" with the cable and its installation than you can with sat stuff.

 

[Terryl]

Ahhh Now I see what your trying to do......OK here is another way to do this, you have a bathroom in the office right...It has a roof vent for the water closet, (or should have) you can use this to come in with the coax, a small hole can be drilled in the vent pipe in the attic or where ever you can get to the vent pipe, the coax can be routed through this hole, the hole can then be sealed with calking.

The vent pipe does not carry water, so there will be no leaks, if the hole is the last thing before going through the roof.

How to route the coax through this pipe.

Step 1, find access to the pipe inside the building, step 2, drill a hole large enough for the coax into this pipe, step 3, using a beaded steel chain (like on a ceiling fan) long enough to reach the roof you pass several inches of one end into the hole in the pipe, step 4, using a magnet on a string you pass this down the pipe from the roof, catching the chain with the magnet, you pull this up to the roof and tie the string on to the chain you pull this back inside and attach the coax to the string, step 5, after you connect everything you seal up the pipe where the coax comes into the building.

Sorry, long winded, too much coffee again.