I live in Norway, and the power system here is 230v 50Hz ('normal' european power?). Only thing I have learned that might be slightly different from other countries, is that we don't have polarized plugs/sockets (is that right?), and there is no difference between the wires, there is no live and neutral wire, the current is the same in both, and when measuring between one of the wires and earth, you get 115v on each. I'm not an electrician, but I'm trying to understand this and I have a couple of friends who know a lot about this. Anyway, I'm not sure if any of this has anything to do with my problem.
I have an extensive collection of US (NTSC) Betamax tapes and VCRs. Long story short, I've always loved Beta, and when ebay came along many years ago, suddenly I could buy tapes and recorders from the US to compliment my collection of European (PAL) Beta stuff.
I also have loads of NTSC VHS tapes and VCR's, all functioning perfectly, with voltage transformers naturally.
But for some reason things have not been so easy with the Betas. In every tape and on every player I use, and regardless of what type of display I use, there is some kind of interference in the picture. I could best describe it as a sort of herringbone pattern, which is more or less visible in the same areas of the picture, depending on how strong the recording on the particular tape is. I feel the tracking range is very narrow, there seems to be only a minute area where the picture comes close to perfect, but it is never really free of the herringbone pattern in certain areas. The areas in question are mainly in the top right quadrant, and bottom left quadrant of the picture. This never changes. Same place regardless of tape/player/display. I know a little bit about helical scanning technology, and understand that one video head does the top half of the picture, and the other head does the bottom half. So it seems to me that the video heads are not getting the job done, since there is interference on both picture halves..
So I got to thinking, could it be the 50/60 Hz thing? No that can't be it, because some of the players actually say 120v 50/60 Hz, while others say only 50 Hz, but the result is the same. Could it be they are not getting enough voltage? The transformers I'm using all say 115v, could the 5v make a difference? All my NTSC VHS players work fine, so do laserdiscs, etc, never seen any interference there, picture is crystal clear. And is nothing to do with wear and tear, I have Beta recorders that are practically brand new, and tapes that have just been taken out of the shrink wrap. The problem is there in some degree all the time. I have lived in different locations and tried these tapes and players over a course of almost 15 years now, same problem the whole time.
But, and this is the strange part; I recently found out that the problem is there only on tapes recorded in the normal BII speed. I just happened to have an old recording made using the slower BIII speed, and it plays perfectly, even if it's not the player it was originally recorded on.. And the tracking range is excellent, I can turn the tracking wheel to the end both ways, and there is not even a hint of interference or even dropouts.. And considering the BIII speed is the equivalent of VHS LP/EP, it really makes no sence that the picture is better than in the faster 'normal' BII speed..
So now I'm really puzzled. Could there be something about the mains power system in this country that interferes with the whole scanning process in Beta BII speed? Some frequency carrier, or switching system or something in BII that doesn't quite work or gets interference when powered from a step down transformer? After all the mains power supply and my step down transformers are the only variables here, so I have no other ideas. Any thoughts? I've tried looking for answers to this on the internet for years, but never ever seen anyone describe this problem before.
Naturally I would have understood if there was a problem with a specific player, or tape, but I have tried at least 7 different Beta recorders, hundreds of tapes, probably close to 10 different displays (CRT TVs, projectors, Plasmas, all multi system compatible), and I have had this equipment hooked up in at least 4 different locations over a period of almost 15 years. No difference.
Looking forward to any help or suggestions I can get
I could of course try to post a couple of pictures of the problem if that is of any help?