Author Topic: Nordmende FG-387 TV signal Generator  (Read 1108 times)

0 Members and 1 Guest are viewing this topic.

Offline crt_cowboyTopic starter

  • Contributor
  • Posts: 39
  • Country: be
Nordmende FG-387 TV signal Generator
« on: February 01, 2022, 03:34:21 pm »
Hi,
I found a Nordmende FG-387 (https://www.radiomuseum.org/r/nordmende_farbbalkengenerator_fg387.html)

The device has two outputs: one with 75ohms and the other one 60hm.
My understanding is that 75ohm is video composite and 60ohm RF modulated. Is that correct ?

Also the device outputs H-SYNC 15KHz. What is it for? In what kind of troubleshooting on TV set was this used for ?

Any advice would be appreciated.
 

Offline Renate

  • Super Contributor
  • ***
  • Posts: 1460
  • Country: us
Re: Nordmende FG-387 TV signal Generator
« Reply #1 on: February 02, 2022, 07:11:37 pm »
That's a pretty looking unit. It would be used for troubleshooting both monitors (with a normal studio 1V P-P 75Ω signal) and TVs (with a modulated RF signal). The H sync output gives you something to sync your 'scope to. You can easily see how/if the horizontal oscillator in your DUT (device under test) is locking up.

Why/how 60Ω was ever a standard is another question. In the US during that time it was mostly 300Ω (balanced) "twinlead" or else 75Ω "cable TV".
 
The following users thanked this post: crt_cowboy

Offline crt_cowboyTopic starter

  • Contributor
  • Posts: 39
  • Country: be
Re: Nordmende FG-387 TV signal Generator
« Reply #2 on: February 04, 2022, 05:31:15 am »
Thanks for the reply. Indeed putting the scope on the 75ohm output confirmed it outputs video signal.
Just out curiosity, why horizontal oscillator and not vertical ? Are there more failures on the horizontal oscillator ?
 

Offline Renate

  • Super Contributor
  • ***
  • Posts: 1460
  • Country: us
Re: Nordmende FG-387 TV signal Generator
« Reply #3 on: February 04, 2022, 11:02:47 am »
Yeah, a lot of generators would have both H & V sync available.
OTOH, back then a lot of 'scopes had built-in 50/60 Hz AC power sync, so that was good enough to look at your V.

Now that I think of it, 60Ω was the old European standard for antenna feeds.
 

Offline crt_cowboyTopic starter

  • Contributor
  • Posts: 39
  • Country: be
Re: Nordmende FG-387 TV signal Generator
« Reply #4 on: February 04, 2022, 05:22:37 pm »
Indeed that's true that 50/60 Hz can be found easily from the AC.
 

Offline decoder_82

  • Regular Contributor
  • *
  • Posts: 165
  • Country: be
Re: Nordmende FG-387 TV signal Generator
« Reply #5 on: February 13, 2022, 05:10:35 am »
Thanks for the reply. Indeed putting the scope on the 75ohm output confirmed it outputs video signal.
Just out curiosity, why horizontal oscillator and not vertical ? Are there more failures on the horizontal oscillator ?

Some signals generators like the Philips PM5508 offers both vertical and horizontal sync.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf