Aurora fault. - UK Vintage Radio Repair and Restoration Discussion Forum

radiograham · 27th Jul 2018, 1:09 am

I suppose this might belong in modern tech section, the Aurora converter I have had for about 10 years has developed a fault, it works fine on the modulator output which I use most of the time. I used to use the video out to make recordings on a VCR and if I wanted to feed a TV with baseband video. The video out is now at a very low level and is no longer usable. Has anyone else experienced this? Does anybody mend these at all in England.

Graham.

rogerdup · 27th Jul 2018, 6:14 am

I'm sure Darryl will be able to fix that!

Dave Moll · 27th Jul 2018, 6:38 am

Quote:

Originally Posted by radiograham

I suppose this might belong in modern tech section.

I would have thought the modulators and standards converters section.

Incidentally, if it's just the baseband output that's affected, I would have thought the problem must be pretty local to that, as there can't be much circuitry between that output and the signal going into the modulator.

Panrock · 27th Jul 2018, 1:37 pm

I take it the relevant phono plug and lead are beyond reproach? Could there now be a bad connection at the Aurora's phono socket due to stresses from heavy use? Does gentle manipulation at the socket make any difference?

Steve

Refugee · 27th Jul 2018, 1:42 pm

I have seen very bad video caused by a missing terminating resistor at the input end of the cable.

rogerdup · 28th Jul 2018, 11:16 am

I have experienced that with a new RCA RF modulator, chinese made. Some soldering to fix inside.

radiograham · 28th Jul 2018, 7:32 pm

Quote:

Originally Posted by Panrock

I take it the relevant phono plug and lead are beyond reproach? Could there now be a bad connection at the Aurora's phono socket due to stresses from heavy use? Does gentle manipulation at the socket make any difference?

I Have had a look inside the aurora, the phono socket is ok and no soldering issues found. I dont want to risk making anything worse as the rf out is fine and I only used the video output occasionally.

tubesrule · 31st Jul 2018, 3:07 pm

Just to chime in:
If the modulated output is working properly than the line level driver must be in working order as that's what's used to drive the modulator. There is a 75 ohm terminating resistor in series with the jack that could conceivably be bad. It would be worth a check. If it checks out good as does the jack, then possibly the cabling or device it's connected to is presenting the fault.

Darryl

radiograham · 1st Aug 2018, 3:17 am

Hi Can I ask is the resistor in question a smd type,I think it must be as when I had a look I didnt see any conventional types,also are there any precautions as to static?. Graham.

tubesrule · 1st Aug 2018, 10:48 pm

Graham,
Yes it's a surface mount device. It will be right along side the connector, closest to the back edge of the board. It may be marked 75- something. You do need to follow standard static procedures like grounding yourself before opening the case and working on the board. You should be able to easily check the resistor with a meter.

Darryl

dragonser · 2nd Aug 2018, 10:48 am

Hi.

Just a quick question. Would it be possible to measure the resistance ( from the phono socket ) to see if the 75R resistor has gone faulty? I'm assuming that if there was a bad connection then the video output would be a lot, lot greater than 75R.

But of course even if the connections were OK the resistance measurement would be above 75R due to the other components. I think ( but may be wrong ) this would need to be done with a digital meter and probably with the unit powered down to avoid the possibility of damaging the circuitry?

stevehertz · 2nd Aug 2018, 11:44 am

Quote:

Originally Posted by dragonser

Hi.

Just a quick question. Would it be possible to measure the resistance ( from the phono socket ) to see if the 75R resistor has gone faulty? I'm assuming that if there was a bad connection then the video output would be a lot, lot greater than 75R.

But of course even if the connections were OK the resistance measurement would be above 75R due to the other components. I think ( but may be wrong ) this would need to be done with a digital meter and probably with the unit powered down to avoid the possibility of damaging the circuitry?

You cannot connect an 'ohm meter' of any sort to live circuitry. You can only measure current, voltage and frequency.

27th Jul 2018, 1:09 am	#1
radiograham Hexode Join Date: Oct 2017 Location: Manchester, UK. Posts: 315	Aurora fault. I suppose this might belong in modern tech section, the Aurora converter I have had for about 10 years has developed a fault, it works fine on the modulator output which I use most of the time. I used to use the video out to make recordings on a VCR and if I wanted to feed a TV with baseband video. The video out is now at a very low level and is no longer usable. Has anyone else experienced this? Does anybody mend these at all in England. Graham.

27th Jul 2018, 6:14 am	#2
rogerdup Retired Dormant Member Join Date: Jan 2018 Location: Chamalières, France. Posts: 167	Re: Aurora fault. I'm sure Darryl will be able to fix that!

27th Jul 2018, 1:37 pm	#4
Panrock Nonode Join Date: Feb 2005 Location: Worcestershire, UK. Posts: 2,368	Re: Aurora fault. I take it the relevant phono plug and lead are beyond reproach? Could there now be a bad connection at the Aurora's phono socket due to stresses from heavy use? Does gentle manipulation at the socket make any difference? Steve

27th Jul 2018, 1:42 pm	#5
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,526	Re: Aurora fault. I have seen very bad video caused by a missing terminating resistor at the input end of the cable.

28th Jul 2018, 11:16 am	#6
rogerdup Retired Dormant Member Join Date: Jan 2018 Location: Chamalières, France. Posts: 167	Re: Aurora fault. I have experienced that with a new RCA RF modulator, chinese made. Some soldering to fix inside.

31st Jul 2018, 3:07 pm	#8
tubesrule Hexode Join Date: Jul 2004 Location: Michigan USA Posts: 325	Re: Aurora fault. Just to chime in: If the modulated output is working properly than the line level driver must be in working order as that's what's used to drive the modulator. There is a 75 ohm terminating resistor in series with the jack that could conceivably be bad. It would be worth a check. If it checks out good as does the jack, then possibly the cabling or device it's connected to is presenting the fault. Darryl __________________ Aurora video standards converters: http://www.tech-retro.com/Aurora_Design/Video_Home.html

1st Aug 2018, 3:17 am	#9
radiograham Hexode Join Date: Oct 2017 Location: Manchester, UK. Posts: 315	Re: Aurora fault. Hi Can I ask is the resistor in question a smd type,I think it must be as when I had a look I didnt see any conventional types,also are there any precautions as to static?. Graham.

1st Aug 2018, 10:48 pm	#10
tubesrule Hexode Join Date: Jul 2004 Location: Michigan USA Posts: 325	Re: Aurora fault. Graham, Yes it's a surface mount device. It will be right along side the connector, closest to the back edge of the board. It may be marked 75- something. You do need to follow standard static procedures like grounding yourself before opening the case and working on the board. You should be able to easily check the resistor with a meter. Darryl __________________ Aurora video standards converters: http://www.tech-retro.com/Aurora_Design/Video_Home.html

2nd Aug 2018, 10:48 am	#11
dragonser Heptode Join Date: Aug 2009 Location: Carshalton, Surrey, UK. Posts: 707	Re: Aurora fault. Hi. Just a quick question. Would it be possible to measure the resistance ( from the phono socket ) to see if the 75R resistor has gone faulty? I'm assuming that if there was a bad connection then the video output would be a lot, lot greater than 75R. But of course even if the connections were OK the resistance measurement would be above 75R due to the other components. I think ( but may be wrong ) this would need to be done with a digital meter and probably with the unit powered down to avoid the possibility of damaging the circuitry? __________________ Regards Peter B