Hmmm. Presumably you mean via using the coaxial output from your Sky TV box, one of those channel 3 or channel 4 kind of things?
My suggestion is to make sure your TV and Sky TV box are connected to each other, with the box also in the correct mode to be transmitting via coaxial output (some of my non STBs (none of them Sky TV) won't, for example, work for simultaneous HDMI and Component connections). Then at the TV (probably somewhere in a setup/settings menu) force an auto channel detect re-scan. I did channel scans on two of my TVs (not JVC) the other week and on both of them it first scanned for digital channels before then also scanning for analogue channels. However, there'd have to actually be something on the wire for the TV to pick something up via the scan.
Right, I had the same question as I send various AV sources around the house via an analogue modulator and I couldn’t believe that the JVC TV didn’t have an analogue tuner.
The solution is that the TV is too clever for its own good and if you select the country as the UK it knows that we no longer transmit analogue TV so won’t try and tune to it but if you select country as other during the initial setup then it will look for analogue channels.
As you have already done the initial setup then you will have to give it a factory reset and go through the whole thing again.
I don’t normally post to forums but when searching for a solution, this was one of the few results I got so thought I’d sign up just to post the solution.