wales@ucla-cs.UUCP (10/06/84)
I recently had a minor problem with my RCA VJT700 VHS VCR, and I would
be interested in knowing whether anyone else with this particular model
has had the same problem.
On the whole, this is a very nice VCR. It has 5 heads, and the tuner is
cable-ready (137 channels). It can be programmed for up to 8 programs
over a 21-day period (counting the entire current week, starting on Sun-
day, as part of the 21 days). Programs can be "one-shot", every day, or
every week on the same day of the week.
The only problem I have had is that the horizontal sync in the "fast
search" mode was slightly out of adjustment. In other words, when I
invoked the "fast search" mode (forward or backward) at SP or SLP speed,
the picture on the TV became unstable and tended to "tear up". The
problem could usually (but not always) be remedied by very careful ad-
justment of the TV's horizontal hold to find a point where the picture
would hold both during searching and normal play.
When I finally got "fed up" and brought the VCR in to the store for re-
pair under their extended warranty, they said it would take about three
weeks (!!) before I could get it back -- whereupon I turned right around
and went back home, VCR still in hand (or rather, arms).
I sent off to RCA for the VJT700 service manual (which cost $18 and took
about two weeks to get), borrowed a friend's oscilloscope, and adjusted
four settings on the recorder servo board: the voltage (nominally
9.5V), the cylinder (recording-head) speed, the capstan speed, and --
most importantly -- the search sync. As it turned out, the search sync
adjustment is very critical and drifts slightly as the VCR warms up. In
order to get it right, I had to let the VCR warm up playing a tape for
about half an hour -- THEN open it up and make the adjustment. It now
works fine once it is warmed up, but search sync is a bit off for 5-10
minutes after the VCR has been turned on.
Now, it's possible that my particular VJT700 has some component in the
search circuits that is abnormally temperature-sensitive. Before look-
ing for something of that nature, though, I'd like to find out if this
is perhaps a generic "misfeature" common to all VJT700's -- in which
case I will simply have to live with its current behavior mode (which,
by the way, is now much better than before, since I made the above ad-
justments).
So, would anyone out there who owns a VJT700 speak up and say whether or
not you have experienced horizontal-hold problems during "fast search"?
If people wish to mail their comments directly to me (using the address
shown in my signature, of course), I will summarize to the net after a
couple of weeks.
--
Rich Wales
UCLA Computer Science Department
3531 Boelter Hall // Los Angeles, CA 90024 // (213) 825-5683
ARPA: wales@UCLA-LOCUS.ARPA
UUCP: ...!{cepu,ihnp4,trwspp,ucbvax}!ucla-cs!wales