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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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23rd May 2023, 8:43 pm | #1 |
Hexode
Join Date: Sep 2005
Location: Powys, Mid-Wales, UK.
Posts: 289
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Marconi TF886 Circuit Magnification Meter
Does anyone have a circuit or manual for the TF886 Q-meter, please? I have one of these in a fairly shabby state and might consider restoring it - but not without a circuit or better still, a manual. I might also sell it, if there's anyone interested.
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23rd May 2023, 10:45 pm | #2 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,894
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Re: Marconi TF886 Circuit Magnification Meter
To make it work, you also need the matching signal sources. They are special with unusually low output impedance. For use with other sig gens, Marconi sold step-down matching transformers.
There were two sig gens, and the TF886 contains two Q meter circuits to cover the full frequency range. David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
24th May 2023, 8:37 am | #3 |
Octode
Join Date: Sep 2004
Location: St. Albans, Hertfordshire, UK.
Posts: 1,478
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Re: Marconi TF886 Circuit Magnification Meter
You might have more luck by asking on the Marconi instruments group here:
https://groups.io/g/Marconi-Test-Instruments
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Regards, Richard, BVWS member |
24th May 2023, 11:35 am | #4 |
Hexode
Join Date: Sep 2005
Location: Powys, Mid-Wales, UK.
Posts: 289
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Re: Marconi TF886 Circuit Magnification Meter
Thanks for the comments so far and special thanks to Dickie for suggesting the MI user group. I have posted there and will let you know whether I get any help there. It seems predominantly digital in content so something as old as an 886 may not register on their radar. I live in hope.
Roger |
24th May 2023, 1:43 pm | #5 |
Octode
Join Date: Oct 2007
Location: Exeter, Devon, UK.
Posts: 1,554
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Re: Marconi TF886 Circuit Magnification Meter
TF886 Q meter.
Roger, while you may have luck with the User Group, often this forum can help. As we are all getting a bit aged now, like the equipment we are trying to get working, the response time is not quite as quick! I attach the manual and 1949 Sales brochure for your model. I also have the manualsand the equipment for the final model TF1245+signal generators TF1246 (40khz - 50Mhz) and TF1247 (20-300Mhz) which are rather more detailed about the operating principles. I also have a very useful Marconi booklet "Measurements by Q meter" of 1951 which covers operating instructions and methods of measurement etc for both the TF329 and TF886. I an scan that if you want it. wme_bill m0wpn Last edited by WME_bill; 24th May 2023 at 1:53 pm. |