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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc.

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Old 20th Aug 2019, 8:52 pm   #41
FERNSEH
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Default Re: Stella ST1007U

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Originally Posted by davyrocket2 View Post
hello David in the photo is that a yellow capacitor i can see which looks like one of its leads is loose
Hi David,
It's C72 (0.047uF) and is a decoupling capacitor connected across the vision and sound circuits HT supply. It was moved away from the tag strip to make access to the bad solder connection.

DFWB.
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Old 21st Aug 2019, 8:38 am   #42
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Default Re: Stella ST1007U

Yes David, the 1768 series always did produce Tom cat sounds when it warmed up presumably due to the pre amp anode load supply being from obtained from the boost rail via that 2.7m resistor.
It's a long time ago but something jolts my memory that the cathode by pass capacitor could be O/C causing this. We are going back to 1964 here! The O/C capacitor had little effect on the sound other than a slight lack of bass. I will dig the manual out when I have a quiet moment. John.
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Old Yesterday, 3:51 pm   #43
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Default Re: Stella ST1007U

Hi John,
This set fixes itself! No more funny sounds during the warm-up period.
Friend Kevin has made a new springy blue steel band for the CRT.

DFWB.
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Old Yesterday, 4:54 pm   #44
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Default Re: Stella ST1007U

In an attempt to improve the picture brightness a 10Kohm wirewound resistor has been connected between the mains input and pin 1 of the CRT. This action has given the tube a 15% boost.

DFWB.
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Old Yesterday, 9:12 pm   #45
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Default Re: Stella ST1007U

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Hi John,
This set fixes itself! No more funny sounds during the warm-up period.
DFWB.
Are you sure Jimmy's cat was not hiding behind the sofa? J.

[I reckon that bias cap healed itself]
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Old Today, 8:07 am   #46
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Default Re: Stella ST1007U

A nice set David, I've not seen one of these "lefties" before, also interesting reading through all the trials and tribulations that it has presented to you.

Cheers
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Old Today, 9:13 am   #47
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Default Re: Stella ST1007U

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Originally Posted by Heatercathodeshort View Post
Quote:
Originally Posted by FERNSEH View Post
Hi John,
This set fixes itself! No more funny sounds during the warm-up period.
DFWB.
Are you sure Jimmy's cat was not hiding behind the sofa? J.

[I reckon that bias cap healed itself]
It was probably both of Kev's Mainecoons .... whilst he [a mechanical genius] played the Jewish Harp on the new CRT band!!!
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