Thread: Carver TX-2
View Single Post
  #25   Report Post  
Posted to sci.electronics.repair
Mark D. Zacharias[_2_] Mark D. Zacharias[_2_] is offline
external usenet poster
 
Posts: 211
Default Carver TX-2


"Don Bowey" wrote in message
...
On 1/28/08 7:54 AM, in article ,
"Chuck" wrote:

On Sun, 27 Jan 2008 13:27:11 -0800, Don Bowey
wrote:

On 1/27/08 12:23 PM, in article
, "Mark D. Zacharias"
wrote:


"Don Bowey" wrote in message
...
On 1/27/08 8:36 AM, in article
,
" wrote:

On Jan 27, 10:48 am, Don Bowey wrote:
On 1/27/08 5:44 AM, in article
,
"Mark D. Zacharias" wrote:







"DaveM" wrote in message
...
"Mark D. Zacharias" wrote in message
. ..

wrote in message

..

.
I just got aCarverTX-2. It works great but when I use the
auto-tune
it will only lock onto an even number freq. I think its set to
the
the
european freq standard. Does anyone know if it can be changed? I
thought there might be just a switch but I cant locate it.
Thanks,
Joe

If the unit is equipped with an AM section, see if it tunes in
9kHz
increments. If so this would confirm your theory about the Euro
frequencies.

I'm not so sure this is your problem, however. The few Euro units
I've
seen mostly tune in 50mHz steps on FM, unlike 100 mHz US models,
but
you
could still tune in a US station using such a tuner. Your tuner
may
have
some other issue - the discriminator out of adjustment, for
example.
This
could make it lock off to one side of station center frequency.
Can
you
set the tuning mode to "manual" (as opposed to "Auto") and get
the
correct frequency to display?

If it is the Euro frequency issue, you can try pressing and
holding a
certain button or say two buttons at once while plugging it in,
or
turning on the power switch if it's a "hard" on-off type.
Sometimes the FM button or freq UP button while plugging in, for
example.

You might get lucky.

Mark Z.

I'm not trying to be a net cop, but you have your numbers and
units
confused. In the US, FM channels are spaced 200 KHz (not 100mHz)
apart,
starting at 88.1 MHz. The usual European spacing is 100 KHz (not
50
mHz).
mHz is millihertz; MHz is megahertz.

From wikipedia concerning FM channel spacing:
The frequency of an FM broadcast station (more strictly its
assigned
nominal center frequency) is usually an exact multiple of 100 kHz.
In
most
of the Americas and the Caribbean, only odd multiples are used. In
some
parts of Europe, Greenland and Africa, only even multiples are
used.
In
Italy, "half-channel" multiples of 50 kHz are used. There are
other
unusual and obsolete standards in some countries, including 0.001,
0.01,
0.03, 0.074, and 0.3 MHz.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate
characters
in the address)

"In theory, there isn't any difference between theory and
practice. In
practice, there is." - Yogi Berra

I was saying that the tuners themselves were often capable of 50
kHz
steps,
which was true. Channel spacing is another matter.

Mark Z.

But your previous post said "50 mHz." 50 milli-Hertz.- Hide quoted
text -

- Show quoted text -

I have determined that the freq step setting is not the problem. I
think it might be the discriminator adjustment. Does anyone have any
advise on how to locate and adjust the discriminator. Thanks, Joe


If the step setting is correct, the discriminator should not require
any
adjustment.



Not true.

Mark Z.


Yawn!



As someone who worked for a Carver warranty station, I can say that
Mark is 100% correct in his diagnosis. Chuck


Nonsense. I don't care where you worked.

Your analysis is simplistic. There are at least several other things that
are more likely.

Why do you discount that the front end or an intermittent stage may be
dead
so no signals are even getting to the discriminator?

Why do you discount that there may be problems with the power supply
and/or
circuit using the tuning voltage?

There is NO reason at all to assume the discriminator has mysteriously
become detuned. You guys hang out on Wiki too much.



See it all the time. This is the voice of experience. They do not
"mysteriously" become detuned. It is a digital circuit controlling an analog
signal, and dependent on analog components, which age and slowly change
value by enough to cause this problem. Anyone who works on this stuff for a
living can tell you that. I already suggested the other things that can
cause this problem - low or missing signal strength, and a bad 7.2 Mhz
crystal.


Mark Z.