Author Topic: Video Amplification/splitter from the internet  (Read 5680 times)

0 Members and 1 Guest are viewing this topic.

Offline Halford

  • Contributor
  • Posts: 29
Video Amplification/splitter from the internet
« on: December 24, 2015, 07:57:37 pm »
Hi everyone and Merry Christmas,

I wanted to build a small video splitter and saw online that I have to do an amplification to keep the video quality.

I found this design(1) that used components that I already have and I made a schematic(2) and a board(3)

end of story, I received the board, soldered everything, no video is coming out at the end. Do you see any error? thanks





images updated
« Last Edit: December 24, 2015, 08:44:13 pm by Halford »
 

Offline bktemp

  • Super Contributor
  • ***
  • Posts: 1623
  • Country: de
Re: Video Amplification/splitter from the internet
« Reply #1 on: December 24, 2015, 08:15:01 pm »
There is no connection between R2/R3 and Q1, so Q1 gets no bias voltage.
 

Offline Aodhan145

  • Frequent Contributor
  • **
  • Posts: 401
  • Country: us
Re: Video Amplification/splitter from the internet
« Reply #2 on: December 24, 2015, 08:16:54 pm »
Be more careful when laying the schematic out. You do not need junctions on the pins of all the components. Only place junctions where you need them when 3 or more wires join.
 

Offline Halford

  • Contributor
  • Posts: 29
Re: Video Amplification/splitter from the internet
« Reply #3 on: December 24, 2015, 08:36:12 pm »
Sorry, I uploaded the wrong eagle images.

there is a junction indeed there, here they are:


 

Offline lincoln

  • Regular Contributor
  • *
  • Posts: 152
  • Country: us
Re: Video Amplification/splitter from the internet
« Reply #4 on: December 25, 2015, 03:46:42 am »
Sorry, I uploaded the wrong eagle images.

there is a junction indeed there, here they are:




ok, but looking at the layout, R3 and R5 don't go any where....
 

Online PA0PBZ

  • Super Contributor
  • ***
  • Posts: 4142
  • Country: nl
Re: Video Amplification/splitter from the internet
« Reply #5 on: December 25, 2015, 11:21:54 am »
ok, but looking at the layout, R3 and R5 don't go any where....

None of the grounds go anywhere, it's like it is following the schematics a bit too literally...  :o
Keyboard error: Press F1 to continue.
 

Offline Halford

  • Contributor
  • Posts: 29
Re: Video Amplification/splitter from the internet
« Reply #6 on: December 25, 2015, 04:12:15 pm »
Well... I'm following it litteraly as I'm a real noob :) ... Got patient and will to explain or tell me where to look to understand it? Thanks anyway
« Last Edit: December 25, 2015, 04:14:19 pm by Halford »
 

Offline LukeW

  • Frequent Contributor
  • **
  • Posts: 666
Re: Video Amplification/splitter from the internet
« Reply #7 on: December 25, 2015, 04:33:29 pm »
Could you post photos of the physical board you've constructed?

I assume there's actually a ground pour connected to all the ground pins.
 

Online PA0PBZ

  • Super Contributor
  • ***
  • Posts: 4142
  • Country: nl
Re: Video Amplification/splitter from the internet
« Reply #8 on: December 25, 2015, 07:16:07 pm »
Could you post photos of the physical board you've constructed?

I assume there's actually a ground pour connected to all the ground pins.

Where would it be, on the third layer?
Keyboard error: Press F1 to continue.
 

Online PA0PBZ

  • Super Contributor
  • ***
  • Posts: 4142
  • Country: nl
Re: Video Amplification/splitter from the internet
« Reply #9 on: December 25, 2015, 07:17:03 pm »
Well... I'm following it litteraly as I'm a real noob :) ... Got patient and will to explain or tell me where to look to understand it? Thanks anyway

All the points marked GND should be connected together.
(That is why they all have the same name)
Keyboard error: Press F1 to continue.
 

Offline Halford

  • Contributor
  • Posts: 29
Re: Video Amplification/splitter from the internet
« Reply #10 on: December 25, 2015, 07:19:43 pm »
all ground are connected.

here is a ratsnest from eagle, and the top and lower image from OSHpark... I was so sure it would work, that I made it print as final online. (probably better then a picture of the circuit)

Thanks for looking



« Last Edit: December 25, 2015, 07:21:54 pm by Halford »
 

Offline Halford

  • Contributor
  • Posts: 29
Re: Video Amplification/splitter from the internet
« Reply #11 on: December 25, 2015, 07:26:08 pm »
I think I found my issue.. bad layout... I feel so idiot.

the 12V input has his gnd not connected to the rest.... I guess this would sabotage the whole circuit.. I feel so stupid.
 

Online PA0PBZ

  • Super Contributor
  • ***
  • Posts: 4142
  • Country: nl
Re: Video Amplification/splitter from the internet
« Reply #12 on: December 25, 2015, 07:27:58 pm »
all ground are connected.

here is a ratsnest from eagle, and the top and lower image from OSHpark... I was so sure it would work, that I made it print as final online. (probably better then a picture of the circuit)

Alright, that looks promising!

Can you measure the DC voltages on the transistors pins and post them?

Keyboard error: Press F1 to continue.
 

Offline lincoln

  • Regular Contributor
  • *
  • Posts: 152
  • Country: us
Re: Video Amplification/splitter from the internet
« Reply #13 on: December 25, 2015, 07:44:39 pm »
I think I found my issue.. bad layout... I feel so idiot.

the 12V input has his gnd not connected to the rest.... I guess this would sabotage the whole circuit.. I feel so stupid.

Its quite all right, nothing a bit of bodge wire will not fix!  :-+
 

Online PA0PBZ

  • Super Contributor
  • ***
  • Posts: 4142
  • Country: nl
Re: Video Amplification/splitter from the internet
« Reply #14 on: December 25, 2015, 07:49:02 pm »
I think I found my issue.. bad layout... I feel so idiot.

the 12V input has his gnd not connected to the rest.... I guess this would sabotage the whole circuit.. I feel so stupid.

Ah yes, floating fills... Been there, done that. Heat your iron and let us know  :)
Keyboard error: Press F1 to continue.
 

Offline LukeW

  • Frequent Contributor
  • **
  • Posts: 666
Re: Video Amplification/splitter from the internet
« Reply #15 on: December 26, 2015, 09:29:51 am »
Did you run an ERC?
 

Offline Halford

  • Contributor
  • Posts: 29
Re: Video Amplification/splitter from the internet
« Reply #16 on: December 26, 2015, 01:05:35 pm »
Thanks guys!

It works perfectly!

Thank you for taking the time to look after my post!

Have a great day!

Hal.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf