As Al would say ROFLMAO! Jeff mailto:Jeff@xxxxxxxxxxxxxxxxxx www.9-11-2001tragedy.com FAX 1-413-280-0677 Intrepid Video & Electronics Harrisburg, PA 17111 717-909-8844 www.intrepid-video.com www.tech-repair.net www.thetoolcaddy.com ----- Original Message ----- From: "Edward Gaidies" <teltek@xxxxxxxxxxx> To: <techassist@xxxxxxxxxxxxx> Sent: Sunday, November 25, 2001 10:18 AM Subject: [TechAssist] Re: Best way to clean a head. > > Really shouldn't travel any miles, at least, if it's screwed down securely. > Sorry Dennis....couldn't resist. ;-) > > -Ed- > > > > > > Larry: > > > > I disagree with your statement, "I takes 2 heads to complete a full picture". > > If on head is bad and the other good you will be missing 1 field of video. If > > you remember oUR NTSC format consists of 1 frame of video is equivalent to two > > fields. The fields are interleaved together not appended to to the end of the > > first field. > > Since they are interleaved together one will end up with 1 line of video and 1 > > line of snow then 1 line of video and 1 line of snow. This pattern will > > continue > > throughout the entire video field. > > > > The reason you get a picture on half of the screen, usually the top, is > > because > > of head protrusion. The surface of the head must impinge into the tape > > slightly > > just after the entrance guide. This impingement depth must continue for the > > entire 180 degree swipe of the video head "A" and repeat this process for > > video > > head "B". > > The main factor that effects head protrusion are wear. Obviously head wear is > > something that only replacement is the answer. Insufficient back tension > > coupled > > with head wear is usually responsible for the assessment mentioned, "even and > > inch of video showing on the screen the heads are good" I would agree with in > > part. > > > > As the video head travels around at 1800 rpm it creates air turbulence, This > > turbulence does not negatively effect the entrance side of the drum assembly > > where the tape meet the head. In fact the trailing side of the video head chip > > had a lower pressure and will suck the tape in closer to the head. But after > > the > > head has traveled 60+ millimeters to playback or record of the first video > > field > > it looses the head to tape contact. One or two primary factors can cause this, > > insufficient back tension and head wear. > > > > Any debris on the drum, or the video, or HI-FI heads can cause the tape to be > > pushed away from the head trying to read it. This is why the air channels in > > the > > drum must be kept free of any debris too. It is just as important as the video > > head chips. > > > > > > I have a brainteaser for the group. How many miles does single video head > > travel > > in 1 single pass of a 6 hour EP VHS tape? > > > > Dennis Viereck > > > > > > > > > > > > > > > > > > Ledstiles@xxxxxxx wrote: > > > >> In a message dated 11/24/2001 4:27:32 PM Pacific Standard Time, > >> billmcfarland@xxxxxxxxxxxxxx writes: > >> > >> << > >>>>> Howdy Wally, > >>>>> If the heads are bad there won't be any video showing on the screen, > >> if > >>>> you have even and inch of video showing on the screen the heads are > >> good, > >>>> > >> Wally . This above is sooooo wrong. Most bad head problems I run across have > >> the 1/2 good picture display. I takes 2 heads to complete a full picture > >> after all. > >> Larry > >> N.C.S. > >> ================================= > >> Help make your TechAssist database better! > >> Submit your fixes here: http://circuitwork.com/techassist/tip/#tips > >> ================================= > >> To UNSUBSCRIBE your email address, click here: > >> mailto:techassist-request@xxxxxxxxxxxxx?subject=unsubscribe > > > > ================================= > > Help make your TechAssist database better! > > Submit your fixes here: http://circuitwork.com/techassist/tip/#tips > > ================================= > > To UNSUBSCRIBE your email address, click here: > > mailto:techassist-request@xxxxxxxxxxxxx?subject=unsubscribe > > > > ================================= > Help make your TechAssist database better! > Submit your fixes here: http://circuitwork.com/techassist/tip/#tips > ================================= > To UNSUBSCRIBE your email address, click here: > mailto:techassist-request@xxxxxxxxxxxxx?subject=unsubscribe > > ================================= Help make your TechAssist database better! Submit your fixes here: http://circuitwork.com/techassist/tip/#tips ================================= To UNSUBSCRIBE your email address, click here: mailto:techassist-request@xxxxxxxxxxxxx?subject=unsubscribe