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Television Standards Converters, Modulators etc Standards converters, modulators anything else for providing signals to vintage televisions.

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Old 27th Jul 2018, 2:09 am   #1
radiograham
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Default 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.
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Old 27th Jul 2018, 7:14 am   #2
rogerdup
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Default Re: Aurora fault.

I'm sure Darryl will be able to fix that!
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Old 27th Jul 2018, 7:38 am   #3
Dave Moll
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Default Re: Aurora fault.

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Originally Posted by radiograham View Post
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.
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Old 27th Jul 2018, 2:37 pm   #4
Panrock
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Default 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
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Old 27th Jul 2018, 2:42 pm   #5
Refugee
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Default Re: Aurora fault.

I have seen very bad video caused by a missing terminating resistor at the input end of the cable.
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Old 28th Jul 2018, 12:16 pm   #6
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Default Re: Aurora fault.

I have experienced that with a new RCA RF modulator, chinese made. Some soldering to fix inside.
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Old 28th Jul 2018, 8:32 pm   #7
radiograham
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Default Re: Aurora fault.

Quote:
Originally Posted by Panrock View Post
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.
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Old 31st Jul 2018, 4:07 pm   #8
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Default 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
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Old 1st Aug 2018, 4:17 am   #9
radiograham
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Default 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.
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Old 1st Aug 2018, 11:48 pm   #10
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Default 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.

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Old 2nd Aug 2018, 11:48 am   #11
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Default 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?
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Old 2nd Aug 2018, 12:44 pm   #12
stevehertz
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Default Re: Aurora fault.

Quote:
Originally Posted by dragonser View Post
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.
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