I've used a Pioneer DVR-440H dvd recorder as pass-through for this purpose. I found that it can accept PAL-60 (and also ntsc-4.43 even though the manual doesn't mention it.), and output standard NTSC.
While I can't speak for that particular JVC model, the line-TBC and digital filtering in video recorders seems to often not be active when playing back NTSC tapes on PAL gear with NTSC playback. The pioneer does a reasonable job at correcting the jitter the line-TBC normally deals with though probably not as good as the build in TBC. Iif you do go this route, I would suggest using the front inputs, as the scart connector on the back seems to be more prone to clipping very high/low video levels for whatever reason.
Other pioneer units from the same line-up (DVR-x40) would probably also work as they're basically the same with some extra features/different drive sizes as far as I know. I know earlier and later models, and many Sony DVD-recorders can also accept PAL-60 though I can't say whether they work for PAL60->NTSC pass-through or just recording. Themaster1 here on the forums mentioned they
had bought one of the later sony RDR-HX models, so maybe they can tell whether it can convert like the Pioneer. The famed Panasonic ES10/15 DVD-recorders willl not work.
Another, probably worse option is finding a VCR that can do ntsc 4.43 (which I believe I've used with a 1-TBC once). I know a number of Sony models does this, they have a switch on the back to switch between PAL-60 and NTSC 4.43. There are also some multi-system units that do both native PAL and NTSC, but they're pretty rare. As these are generally cheaper consumer machines though, the playback is probably not as great and you won't have any line-tbc functionality in the VCR itself.
