VHS Tape path alignment scope and no scope

[Music] [Music] [Applause] [Music] in today's video I'm going to show you how to do a tape path alignment on this JBC whatever this is you guys have seen this thing too many times what is it it's an hrd 870 of course we're going to do a tape path alignment on this this is the machine you've seen this thing three times before now this is the fourth video and maybe we'll make some more on this one this is quite a common machine so a very popular machine there was very many models that JBC made that use the same chassis so what you see here can be applied to many different uh machines uh I've intentionally buggered up the tape path alignment on this thing so that uh we can do an alignment using a scope so if I put it on play well you'll see it's just an absolute mess okay looks like crap so what we're going to do is we're going to hook up the scope maybe til the scope a bit so you can see it a bit better maybe move the camera a bit first thing we need to do is we need to find our switching test point put on channel two our switching test point on this machine here is on this connector the green connector I believe it's like the third one over from the right there it is there's our switching pulse I've got my scope set up to trigger off of channel two so we're going to trigger our scope from that only we can get this seem to stay in there there we go okay now we can go back to channel one we need to find our RF test point and our RF test point is going to be one of these shielded wires here off of this other plug there's our RF test point there so we'll just put our scope in on that RF test point there okay this is a mess we want this waveform to be flat so what we're going to do is we're going to adjust our top and bottom guides to do that try to do this without standing too much in the shot grab my little uh screwdriver for adjustment and we'll just pick one to start with and as you can see I'm making it worse this is the end of my test this is the end of my uh frame here so I want to adjust that so that there we go it's relatively flat there that's the bottom the top side is is over here if I look at the screen here you'll see what I've got [Music] now and now we're going to just try adjusting the top side guide to bring it back flat sort of flat okay that's getting there we're not quite perfect yet we're close but we're not quite we'll go back to the other guide over here and we'll just adjust did to make our output perfectly flat it's not showing up on the camera because of the Rolling shutter but it is completely flat and now if I Pan the camera up you'll see with the nice bar in the middle of the screen which is caused by the Rolling shutter on the camera that our tape path is back to [Music] normal now on here there should be a tracking adjustment if I can find it tracking press the tracking control on here it's an auto track mode now as you can see what happens when I adjust the [Music] tracking if I press both buttons it should go to auto okay so now it's an auto and now I can see looking at this that my entrance guide is off a little bit because this is the Leaning Edge right this is the this is the end of the scan this is the start of the next scan so I'm going to go back down to my my entry guide and I'm going to adjust it ever so slightly to try and [Music] bring that back completely flat or as close as we can getting it to [Music] flat wrong [Music] way pretty close pretty close there that is pretty darn good airplane flying over of course there's our playback complete with the drop oats on the [Music] tape that's tape path alignment using a scope you can do this without a scope too if I want to do it without a scope I can uh disconnect the scope here I can mess with the guides you make the picture all screwed up I'll mess with both guides just to mess up the picture big time okay looking at the screen here I want to adjust it I'm just going to I rewind my tape my tape just got to the end so we'll just let the tape rewind and we'll start over from the beginning okay again I shouldn't be using this camera to shoot the screen on this because of the rolling shutter effect it's really is pathetic on these um camos cameras I should have been using my hdb camera with the CCD imager because it would get a much better shot off the screen anyway I'm just going to adjust my guide post here and I'm going to adjust it until I get my the least number of lines at the bottom of the screen okay and now I'm going to go to the other guide and I'm going to adjust it ever so slightly and just one way or the other to [Music] try and get the picture in the P3 guide on the or P2 guide on the left side of the drum is going to affect the top portion of the pitcher in the P3 guide the on the right side of the drum is going to affect the bottom portion of the [Music] pitcher [Music] for now without using a scope you're never going to get it 100% perfect but that was done without using a scope let's just reconnect the scope as you can see my scope is not connected let's just reconnect my scope and we'll see how close I got it just by eyeballing it with the monitor it's not going to be exact but as you can see it's pretty damn close to being bang on so you can do it without a without a scope it's just it takes longer with the scope you know exactly where to go uh I got my ENT or my exit guide I got pretty much perfect it's perfectly flat there my uh entry side guide I'm off just to smidge but again now it's perfect there you go um pretty simple uh pretty simple repair here so I hope you enjoyed tape path align it both using a scope and without a scope we will catch you in the next video bye

Channel: 12voltvids

Views: 19,036

Keywords: VHS (Film Distribution Medium)

Id: 33donH0J-vI

Length: 9min 52sec (592 seconds)

Published: Mon Jun 08 2015