Toshiba TV29C90 problem; Image fades to black...

if its a cheap transmitter, chances are it uses a crystal oscillator at a
low fundemental frequency, and uses a frequency doubler tank to get your
desired frequency. something is wrong there.

a frequency counter and spectrum analyzer would be good for situations like
this.


<stickyfox@gmail.com> wrote in message
news:1162482896.216285.27010@m7g2000cwm.googlegroups.com...
I've got a JR 72 MHz transmitter module that was transmitting a very
weak signal on the correct frequency. I replaced the power transistor
and the module worked for a few minutes, but now it transmits a very
strong signal on 144 MHz. There is no signal being transmitted on 72
any more. I imagine I've got to get the crystal back into its
fundamental mode but I could use some hints. Does anyone have a service
manual or schematic for the module?

A 2m RC system would be really neat but I don't think it'll be easy to
find a receiver.
 
stickyfox@gmail.com a écrit :

FWIW.. not that it helps:

144 MHz is the American 2m ham band, for which I have a license.. I
left that out. It's not exactly in the band plan for RC aircraft but
it's not like I'd be causing real aircraft to plummet to the earth.

Thanks for the tip about capacitance. There is a trimmer cap on the
board right next to the crystal, I assumed it had something to do with
tuning the feedback but I don't even know what kind of oscillator it
was so I was hesitant to just start twisting knobs.
It is very difficult to get schematics/ service manual in the RC hobby.
Some kind of trade secrets, maybe.

Probably the trimmer cap is there to adjust the frequency shift at
+/-1.5kHz from center frequency. This is the FSK system used in RC
equipments.

Did you used the correct replacement transistor?

Try posting on http://groups.google.com/group/rec.models.rc.air .


Daniel
 
"William R. Walsh" wrote:
Hi!

If you do, you'll need a new toothbrush, or a new wife.

I'd strongly suggest the new toothbrush route. :)

William

What if the wife is already out of warranty?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
Baron wrote:
Michael A. Terrell wrote:

Baron wrote:

Michael Kennedy wrote:

Take a soldering iorn and unsolder the flash on both units, then
solder the flash chip you want to recover onto the new flash
drive's board.

In short I highly doubt you have the soldering skills needed to do
this. You could learn, but it would still be very tricky.


avri.schneider@gmail.com> wrote in message
news:1162543545.945798.73190@e3g2000cwe.googlegroups.com...
That's exactly what I want to do - how do I do that?

Thanks,
Avri


Without a hot air removal tool.... Almost impossible to remove
damage
free ! Also the chip may be bonded to the pcb !

--
Baron:


I used to change 288 pin CPU chips on embedded controller boards by
hand, while working under a stereo microscope. It takes a very steady
pair of hands, lots of practice, and really good tools, but it can be
done.

Without a doubt ! I never had the luxury of a microscope. <Envy
The hot air kit cost an arm and a half, but it made the job ten times
easier to do ! From my point of view the component was usually dead
anyway ! It was more important to minimise board re-work damage.

The microscope belonged to the company, but I swiped it from
production so often that they bought me one to use. I did my own rework
on PC boards that cost us over $8000 to assemble. I also forced them to
buy a 100 pound case of .015" Ersin rework solder. I got one of the
engineers to order a sample roll, and passed out a couple feet here, and
a couple feet there. Soon, every assembler, rework worker, and tech was
demanding a roll. ;-)

The ICs I was reworking cost us up to $80 each, in large quantities.
I would inspect a board before I tested it, do any rework it needed,
then run the 20 to 30 page test procedure.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
B,
tks for your reply.
Yes, The modulator is Pal B/G with 6.5 MHZ sound sub carrier. I need to
make it back to Pal B/G WITH 6 MHZ SOUND SUB CARRIER.
the modulators are ordered mistakenly with sound carrier 6.5 mhz apart
from the video signal.
I now need to tune it back to make it work in a country where the tv
are pal b/g 5.5 or 6 mhz sound carrier.
peter
b wrote:
kwansfamily@yahoo.com ha escrito:

I have a small broadcast CABLE tv system. Using 12 Modulators
which accept 12 Audio /Video signals and output composite RF signal.
Each RF output of each Modulator will then feed a signal mixer. So
there are 12 channels. The system is PAL B/G with 6.5 sound spacing.
The problem is that most of the users have only PAL B/G 6 mhz
Televisions. So the users can get the video picture but no sound OR
SOUND WITH TERRIBLE HUMMING
Question is how I can tune the modulator with 6.5 mhz of sound spacing
TO SOUND SPACING 5.5 OR 6 MHZ.

PETER

If you are talking about the audio carrier, Pal BG is 5.5mhz and Pal I
is 6mhz. There is no such thing as a ' Pal BG 6mhz
telvision'....perhaps you need to rephrase your question, as it doesn't
seem to make sense.
-B.
 
kwansfamily@yahoo.com wrote:
B,
tks for your reply.
Yes, The modulator is Pal B/G with 6.5 MHZ sound sub carrier. I need to
make it back to Pal B/G WITH 6 MHZ SOUND SUB CARRIER.
.....6.0 ? 6.5? that's *not* pal B-G!!!

pal D is 6.5
pal I is 6.0

what you mean to say is that you're trying to adapt a pal- D device to
a pal-I.
Usually this involves changing a few coils.

-B.
 
On Mon, 06 Nov 2006 20:42:41 +0000, ian field Has Frothed:

http://www.mirror.co.uk/news/tm_headline=exclusive--tories-secret-plot-to-privatise-our-roads&method=full&objectid=18043482&siteid=94762-name_page.html
No because the federal gov here can use federal funding of state
roads as a pawn to make individual states comply with speed limits, seat
belt and other laws.


--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794
 
"ian field" <dai.ode@ntlworld.com> wrote in message
news:57N3h.5330$hK2.4130@newsfe3-win.ntli.net...
http://www.mirror.co.uk/news/tm_headline=exclusive--tories-secret-plot-to-privatise-our-roads&method=full&objectid=18043482&siteid=94762-name_page.html
Yes we do. About 6 months ago it was widely reported that the French bought
interstate highway I-95, which connects Miami, Florida to the Washington, DC
area.

I did not track down all of the sources, but it was rampant in forwarded
emails.
 
ian field wrote:

http://www.mirror.co.uk/news/tm_headline=exclusive--tories-secret-plot-to-privatise-our-roads&method=full&objectid=18043482&siteid=94762-name_page.html
You mean they're determined to throw the next election away AGAIN ???

Graham
 
mwpmorris@gmail.com wrote:
Hi,

I've just dropped my CRT monitor while moving house. I powered it up to
see if it still worked. It made a loud electrical buzzing sound and
sparked inside at the back.

Before I dumped it in the bin I thought I'd have a peek inside to see
if I thought it was repairable. The clear glass at the very back of the
CRT had shattered, I think around the electron gun/heater - so I guess
it ain't repairable!

Since then I've read bits about lead-lined glass and x-rays, so I'm
worried.....

Could I have been exposed to anything when the glass shattered inside
the set or when I powered the thing on with the glass shattered?

Thanks.

No, you should wash your hands after handling leaded glass but to
generate xrays you need extremely high voltage and a hard vacuum, in
short, it ain't gonna happen with a modern monitor, especially not a
broken one. The Xray warnings are a holdover from the days of vacuum
tube rectifiers.
 
"ian field" <dai.ode@ntlworld.com> wrote in message
news:57N3h.5330$hK2.4130@newsfe3-win.ntli.net...

Australians already own a number of US toll roads.
 
mwpmorris wrote:

Well my foot hurts a bit. I'm guessing that's from when I dropped the
monitor on it.
No thats a pain in your wallet ! The insurance Co should take care of
that !

--
Baron:
 
mwpmorris@gmail.com ha escrito:

Hi,

I've just dropped my CRT monitor while moving house. I powered it up to
see if it still worked. It made a loud electrical buzzing sound and
sparked inside at the back.

Before I dumped it in the bin I thought I'd have a peek inside to see
if I thought it was repairable. The clear glass at the very back of the
CRT had shattered, I think around the electron gun/heater - so I guess
it ain't repairable!

Since then I've read bits about lead-lined glass and x-rays, so I'm
worried.....

Could I have been exposed to anything when the glass shattered inside
the set or when I powered the thing on with the glass shattered?

Thanks.
not likely to be any health risks from powering it up in that state.
now get on your local freecycle and get another monitor! sure you could
give one a good (new) home.
-B
 
"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:454FA0FA.9663873B@hotmail.com...
ian field wrote:

http://www.mirror.co.uk/news/tm_headline=exclusive--tories-secret-plot-to-privatise-our-roads&method=full&objectid=18043482&siteid=94762-name_page.html

You mean they're determined to throw the next election away AGAIN ???

Graham
As often as possible hopefully!
 
Hi!

Could I have been exposed to anything when the glass shattered inside
the set or when I powered the thing on with the glass shattered?
Other than maybe some trace amounts of ozone that might have generated by
the arcing...no.

If you think you came into contact with any broken glass, the best thing to
do would be to wash your hands. That should take care of most anything that
would come out of a monitor.

I'm surprised that the monitor broke like that. It seems the most common
damage from a drop is a dislodged shadow mask, which usually messes up the
colors on the screen. As an aside, I once lost ahold of an IBM 8513 and it
fell down a flight of stairs. It made an awful racket going down the stairs,
but was fine apart from some scuffing when I picked it up and checked it
out. I can only guess that the small tube size (12") might have been what
saved the shadow mask in that monitor from popping loose or distorting.

William
 
ian field wrote:

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:454FA0FA.9663873B@hotmail.com...


ian field wrote:

http://www.mirror.co.uk/news/tm_headline=exclusive--tories-secret-plot-to-privatise-our-roads&method=full&objectid=18043482&siteid=94762-name_page.html

You mean they're determined to throw the next election away AGAIN ???

Graham


Actually the thieving Toraidhe (Gallic origin of the word "Tory" - meaning
bandit - the "d" is silent) weren't going to tell us about this until after
they get back in, but it was posted on their website by mistake and hastily
removed when they realised their blunder!
Really ?

Oh joy !

Graham
 
On Mon, 06 Nov 2006 20:42:41 GMT, "ian field" <dai.ode@ntlworld.com>
wrote:

http://www.mirror.co.uk/news/tm_headline=exclusive--tories-secret-plot-to-privatise-our-roads&method=full&objectid=18043482&siteid=94762-name_page.html

I don't know about roads but some municipal governments are selling
off water/sewer utilities to private companies. I imagine that is the
case in Europe as well.

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----
 
On Mon, 06 Nov 2006 21:03:24 GMT, "Homer J Simpson"
<nobody@nowhere.com> put finger to keyboard and composed:

"ian field" <dai.ode@ntlworld.com> wrote in message
news:57N3h.5330$hK2.4130@newsfe3-win.ntli.net...

Australians already own a number of US toll roads.
For your sake I hope we didn't build them for you.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
Charlie East wrote:

D-


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
ian field wrote:
stratus46@yahoo.com> wrote in message
news:1162844818.923611.136930@h54g2000cwb.googlegroups.com...
mwpmorris wrote:
Well my foot hurts a bit. I'm guessing that's from when I dropped
the
monitor on it.

Nah. the pain is from when the vacuum fell out on your foot.

GG


No it didn't - vacuum floats because its lighter than air.

Only in the Northern Hemishere.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 

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