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Title: Need assistance ID'ing a capacitor Post by: WA2SQQ on January 14, 2020, 09:50:31 AM Not directly AM related, but I need a quick answer to a component identification situation. I’m at the office and don’t feel like waiting till I get home to measure this. This USB dongle has 3 caps in parallel, labeled “1201J” I know the J is 5% tolerance. Caps usually have a 3 digit code, but this one appears to be 4. Anyone know about 4 digit cap codes?
Interesting circuit, from a device marketed to high end audio people – a USB line conditioner. Ground (pin 4) is separated from USB shell part of the connector. Simple RC network comprised of the 3 caps in series with a 33 ohm resistor between the shell and ground. Possibly it might improve a ground loop situation but hardly what customers who purchased it claim it does. Anyone want to guess what this sells for? $299 – No joke! Title: Re: Need assistance ID'ing a capacitor Post by: N4LTA on January 14, 2020, 11:07:59 AM I'd guess 1200pF but I might be wrong. 1201 on a SMD resistor usually means 1200 ohms - usually...
Pat N4LTA Title: Re: Need assistance ID'ing a capacitor Post by: K1JJ on January 14, 2020, 12:00:11 PM I had a box of silver micas that were marked 39J, 202J, etc. They were all picofarad, meaning 39 pF, 202 Pf....
So in your case this could mean 1200 pF = the more common .0012 uF. Just a guess though. T Title: Re: Need assistance ID'ing a capacitor Post by: KD6VXI on January 14, 2020, 12:07:42 PM http://m.diytechstudio.com/apps/4-digit-capacitor-value/4-digit-capacitor-value-finder AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
--Shane KD6VXI |