Hello, i have a situation that is driving me a little crazy. I recently moved a 1.5 GHz STL. The antenna is connected with 1/2" coax. The existing installation was used but the TX/antenna distance after the move is a full meter longer. So I made an extension of 1/2" cable. The cable of the main installation was slightly bent before the connector, as well as the extension that is attached to the n connector of the link. Instead of the usual approx. 0.7w, the indicator on the display showed only 0.08w. I checked all the connectors in the chain and I didn't find a defect anywhere.
When I completely straightened the incoming cable and bent the jumper cable into S shape the power did start to rise. Insane part was the fact that sharper S shape gave result more power appearing on the display.
Considering that at lower UHF and VHF frequencies I have never noticed any correlation between the slight bending of the coax and the disturbance of the electrical characteristics of the cable, I am interested about forum members experience in the L band with this phenomenon (or perhaps i am on wrong trace).

I would replace all the coax. It may have an intermittent contact inside.

Thank you for your reply. I'm thinking about that too. On the other hand, it is very difficult to make a break inside 1/2 heliax. Coax is robust and if there is damage to the inner conductor, signs of damage must be visible from the outside as well. Plus this piece of extender I worked with new coax and brand new rfs n connectors.
I've never seen anything like this before.

Unfortunately, that's not true - I've had poorly assembled commercial cables that have had damaged centre conductor without any visible external sign of damage. One of these iffy cables was an N-type lead (supplied with a Spectrum Analyser) where the centre conductor must have been soldered under tension, and exhibited similar problems to those you describe.

I'm inclined to agree with "Krakatoa" further up the thread. Try a new cable.

thanks guys for the advice!