Will coupling cable harm the receiver?

[Crest]

Is it ok to couple an RG-6 run if it is too short? I noticed a little bit of signal strength dropoff (as much as 17 points on some transponders), but the picture is fine. I only added 25' more of RG-6 from about 57' RG-6 initially installed to one receiver, and used a store-bought coupler suitable for RG-59.

[Mike123abc]

You might need a higher quality coupler. Couplers are needed for example where the cable goes into the house it goes through a grounding coupler.

[Crest]

You might need a higher quality coupler. Couplers are needed for example where the cable goes into the house it goes through a grounding coupler.

Sorry, Mike, I explained it wrong. Cable goes from dish to grounding block outside of house. Then used to go directly from ground block to receiver, but that's where I put the F to F cable coupler: in between the line from ground block to receiver. Any ideas where to get a better in-house cable coupler F to F connector? Thanks for the info.