Hitachi VT-7S & VT-6800S

[jmespe]

hi !
well , as far as I know, there is not a trimmer to adjust
in vhs , the speed of the tape is controlled by ... many things
(there are some analogic "loops" )
for instance; the drum is accurately synchronysed with picture frequency
(180° of the drum = half a picture ; odd or even)

but I don't know exactely what control the speed in vhs
and not in this particular model
I thing it has something to do with the "ctl" signal which is recorded next to the linear audio...