Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #41   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 178
Default CRT question

On 26/08/2019 1:57 am, Andy Burns wrote:
Trevor Wilson wrote:

Try a Rigol DS1054z. A very impressive 'scope for not too much cash


And easily hackable to add extra bandwidth and features.


**Yep. Buy the 50MHz model and convert it to 100MHz. Worst thing about
the Rigol is the probes. Truly horrible probes. The worst I've ever used.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

  #42   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 907
Default CRT question

On 2019/08/25 11:24 a.m., wrote:
On Sun, 25 Aug 2019 10:51:23 -0700, Jeff Liebermann
wrote:

On Sat, 24 Aug 2019 20:04:54 -0700 (PDT), Jeff Urban
wrote:

How can you build an electronic circuit without having the schematic ?


I built quite a few Heathkit kits in the distant past that did not
require the use of a schematic. A schematic was provided by Heathkit,
but it was only useful for learning how everything works and for
troubleshooting.

I worked for a Heathkit store in the distant past for a few months.
Most of what I found were the wrong parts in the wrong holes in the
PCB. Occasionally, it was missing, extra, or substituted parts.
Amazingly, I did find one design error. Heathkits spent considerable
time and effort to avoid any assembly instructions or documentation
errors. The unspecified manufacturer of this kit might not have been
able to do as good a job. Methinks it might be worthwhile checking if
there are any addendum, corrections, mods, or changes.

I can usually find someone else's mistakes rather quickly, but have
had less luck finding my own mistakes. Maybe having someone else
check the CRT circuitry for assembly errors might be useful.

Hint: That which is obviously correct, beyond any need of checking,
is usually the problem.

I did have someone check my work and he said it should work. And it
does except for the changing focus. I am now thinking that somehow the
voltages need to be changed. The heater voltage is just below the
lowest voltage given on the spec sheet for the CRT.
Nevertheless I am going to go back and check all the solder joints
with a magnifier. And double check all the component values. The weird
thing to me is that the thing works. It just goes out of focus
gradually from one side of the display to the other.
Thanks,
Eric


Eric, have you tried contacting the kit maker? It may be a problem with
the kit that he/she wasn't aware of - defective component, etc. It happens!

'howchon at hotmail dot com' (from the home page).

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
  #43   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,212
Default CRT question

On 25/08/19 19:05, wrote:
On Sun, 25 Aug 2019 10:37:07 -0700, Jeff Liebermann
wrote:

SNIP
Yeah Jeff, it really is a kit. Here's the link:
http://oscilloscopeclocknixiecrt.com/Kit.htm
I wish I had traced out the circuit before I populated the board. But
it's double sided and now really hard to see where traces go when they
hide under components.
Eric


Rather off-topic, but in one of the pictures (uncaptioned, about 2/3 to
3/4 of the way down, where the clock is on a stepped, wooden base) the
valves are nicely coloured - green on the left, purple top right, and
blue bottom right. I assume these are simply non-functional valves with
a coloured led hidden in the base. Those are pretty unusual colours for
leds; maybe a white led with a coloured filter has been used. And are
the valves non-functional? I would expect the base to get pretty hot
with the filament at that end. Not a good environment for an led.

--

Jeff
  #44   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,249
Default CRT question

Jeff Layman wrote:

--------------------



Rather off-topic, but in one of the pictures (uncaptioned, about 2/3 to
3/4 of the way down, where the clock is on a stepped, wooden base) the
valves are nicely coloured - green on the left, purple top right, and
blue bottom right. I assume these are simply non-functional valves with
a coloured led hidden in the base. Those are pretty unusual colours for
leds; maybe a white led with a coloured filter has been used. And are
the valves non-functional? I would expect the base to get pretty hot
with the filament at that end. Not a good environment for an led.


** Likely the valves are not operating and the rather bright light is coming from thin ,coloured filament bulbs - as used for xmas decorations and tree lighting.

The hole in the bottom of a 9 pin valve base is not very big.



..... Phil
  #45   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 12,364
Default CRT question

On Monday, 26 August 2019 08:05:38 UTC+1, Jeff Layman wrote:
On 25/08/19 19:05, wrote:
On Sun, 25 Aug 2019 10:37:07 -0700, Jeff Liebermann
wrote:

SNIP
Yeah Jeff, it really is a kit. Here's the link:
http://oscilloscopeclocknixiecrt.com/Kit.htm
I wish I had traced out the circuit before I populated the board. But
it's double sided and now really hard to see where traces go when they
hide under components.
Eric


Rather off-topic, but in one of the pictures (uncaptioned, about 2/3 to
3/4 of the way down, where the clock is on a stepped, wooden base) the
valves are nicely coloured - green on the left, purple top right, and
blue bottom right. I assume these are simply non-functional valves with
a coloured led hidden in the base. Those are pretty unusual colours for
leds; maybe a white led with a coloured filter has been used. And are
the valves non-functional? I would expect the base to get pretty hot
with the filament at that end. Not a good environment for an led.


LEDs in all sorts of oddball colours do exist, they're just a good bit more money & thus unpopular.


NT


  #46   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 2,163
Default CRT question

On Sun, 25 Aug 2019 21:38:25 -0700, John Robertson
wrote:

On 2019/08/25 11:24 a.m., wrote:
On Sun, 25 Aug 2019 10:51:23 -0700, Jeff Liebermann
wrote:

On Sat, 24 Aug 2019 20:04:54 -0700 (PDT), Jeff Urban
wrote:

How can you build an electronic circuit without having the schematic ?

I built quite a few Heathkit kits in the distant past that did not
require the use of a schematic. A schematic was provided by Heathkit,
but it was only useful for learning how everything works and for
troubleshooting.

I worked for a Heathkit store in the distant past for a few months.
Most of what I found were the wrong parts in the wrong holes in the
PCB. Occasionally, it was missing, extra, or substituted parts.
Amazingly, I did find one design error. Heathkits spent considerable
time and effort to avoid any assembly instructions or documentation
errors. The unspecified manufacturer of this kit might not have been
able to do as good a job. Methinks it might be worthwhile checking if
there are any addendum, corrections, mods, or changes.

I can usually find someone else's mistakes rather quickly, but have
had less luck finding my own mistakes. Maybe having someone else
check the CRT circuitry for assembly errors might be useful.

Hint: That which is obviously correct, beyond any need of checking,
is usually the problem.

I did have someone check my work and he said it should work. And it
does except for the changing focus. I am now thinking that somehow the
voltages need to be changed. The heater voltage is just below the
lowest voltage given on the spec sheet for the CRT.
Nevertheless I am going to go back and check all the solder joints
with a magnifier. And double check all the component values. The weird
thing to me is that the thing works. It just goes out of focus
gradually from one side of the display to the other.
Thanks,
Eric


Eric, have you tried contacting the kit maker? It may be a problem with
the kit that he/she wasn't aware of - defective component, etc. It happens!

'howchon at hotmail dot com' (from the home page).

John :-#)#

Yes, I did contact him. He has tried to help but so far nothing.
Eric
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
HP CRT filament question dodger741 Electronics Repair 4 May 28th 08 12:35 AM
Fire Up CRT TV/DVD Without CRT Connected? JR North Electronics Repair 3 May 16th 06 03:37 AM
Can one "overclock" a CRT monitor's video input bandwidth? Need slightly higher refresh rate than my existng CRT allows... Ken Moiarty Electronics Repair 32 April 26th 06 07:58 AM
Newbie question on CRT moniter failure, chirping David Merryman Electronics Repair 3 July 9th 05 02:55 AM
Viewsonic (P225f) monitor question (or any viewsonic CRT question) Falkentyne Electronics Repair 2 June 18th 05 08:52 AM


All times are GMT +1. The time now is 11:34 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"