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Television Standards Converters, Modulators etc Standards converters, modulators anything else for providing signals to vintage televisions. |
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21st Sep 2005, 6:40 pm | #1 |
Dekatron
Join Date: Feb 2005
Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW
Posts: 3,517
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Darius Modulator build
Hi Darius,
I wondered what sort of insertion loss you measured with your output filters?? I have made the London one, and althogh it does indeed work between 41 and 45 megs I get a very high loss at operating frequency (around 20db) Has anyone else built these? Cheers Sean
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Engineers make things work and have spare bits when finished |
21st Sep 2005, 8:54 pm | #2 |
Dekatron
Join Date: Feb 2005
Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW
Posts: 3,517
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Re: Darius Modulator build
Ok, well, I have built a different filter, with my own component values, much less insertion loss!
Pictures below! Cheers Sean
__________________
Engineers make things work and have spare bits when finished |
22nd Sep 2005, 8:25 am | #3 |
Retired Dormant Member
Join Date: Dec 2003
Location: Solingen, Germany
Posts: 727
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Re: Darius Modulator build
Good morning Sean,
no remarkable losses. Maybe one tuned circuit was not in tune. Please let me see your filter frequency response! Attached a few pics of the modulator used in the MK III converter. Hope it's helpfull. Kind regards Darius |
9th Dec 2005, 8:14 pm | #4 |
Retired Dormant Member
Join Date: Dec 2003
Location: Solingen, Germany
Posts: 727
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Re: Darius Modulator build
Good evening,
for all those who want to build it, a universal video board kit comes up in january. It contains the vision stages for the modulator. A lot of usefull things for vintage tv can be done with this board. A discription and a schematic will come up soon in an extra thrad. Kind regards Darius |