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1. Shard Calculation

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Response:

Calculated Shard: 36 (from laksa156)

2. Crawled Status Check

Query:

curl -X POST \
  'http://laksa036.int.ahrefs:8124/' \
  -H 'Content-Type: text/plain' \
  -H 'X-ClickHouse-Database: crawler3' \
  -H 'Authorization: Basic YXBpOg==' \
  -d 'SELECT getAhrefsURLFromUnparsed(src_unparsed) AS found_url, ifNull(toUnixTimestamp(download_stamp), 0) AS crawl_time, ifNull(toUnixTimestamp(props_url_first_seen), 0) AS first_indexed_time, download_http_code AS http_code, src_unparsed AS src_unparsed, src_root_hash AS src_root_hash, history_drop_reason AS history_drop_reason, meta_title AS meta_title, meta_descriptions AS meta_descriptions, attrs_boilerpipe_text AS attrs_boilerpipe_text, attrs_markdown AS attrs_markdown, attrs_readable_markdown AS attrs_readable_markdown, meta_canonical AS meta_canonical FROM crawler3.page_info_local FINAL PREWHERE (src_root_hash, src_unparsed) IN ((getAhrefsRootHashFromUnparsed(getAhrefsUnparsedNoserviceFromURL(\'https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/\')), getAhrefsUnparsedNoserviceFromURL(\'https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/\'))) FORMAT JSONEachRow'

Response:

{"found_url":"https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/","crawl_time":1772828852,"first_indexed_time":1728233239,"http_code":200,"src_unparsed":"com,diyaudio!www,\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/ s443","src_root_hash":"460465978056853036","history_drop_reason":null,"meta_title":"What does the R in resistor value 240R mean? | diyAudio","meta_descriptions":["I'm a newbie in the world of DIY electronics, and was wondering where I can get info on what the R means in 240R resistor on a schematic. I know it's..."],"attrs_boilerpipe_text":"#1\nI'm a newbie in the world of DIY electronics, and was wondering where I can get info on what the R means in 240R resistor on a schematic. I know it's probably a simple question, but I am a beginner.\n#2\n240R means  240 Ohm : O )\n#3\n1R8 = 1,8 ohm\n10R = 10 ohm\n1k2 = 1,2 kohm\n12k = 12 kohm\n1M = 1 Mohm\nGet it?\n#4\nThe 'letter marker for decimal point' system was introduced to reduce  reading errors on schematics; with resistors using 'R' also means you don't have to remember how the heck to get the ohm symbol ( Ω ) - more info\nhere (pdf).\n#5\nR means resistance and is used instead of the decimal point.\nThe decimal point is sometimes hard to see.\n#6\nto complicate things here's the info I got on caps ratings:\nQUICK REFERENCE CHART (Decade values)\n1R0 =   1pF        103 = .01uF\n100 =  10pF        104 =  .1uF\n101 = 100pF        105 =   1uF\n102 =.001uF        106 =  10uF\n1010= Some numbers used on 10 meters!\nI saw that in datasheets too (though you very rarely come across caps smaller than 10pF, so the \"R\" is hardly ever seen on capacitors anyway)\nJust to say that \"R\" probably means something else than resistance in that code...\n#7\nDominique said:\nto complicate things here's the info I got on caps ratings:\nQUICK REFERENCE CHART (Decade values)\n1R0 =   1pF        103 = .01uF\n100 =  10pF        104 =  .1uF\n101 = 100pF        105 =   1uF\n102 =.001uF        106 =  10uF\nThose numbers are usually seen marked on the part rather than in a schematic, especially on small caps. A bit like resistors, the first two give the value, the third the multiplier (number of zeroes), result in picofarads, so 472 = 4,700pf = 4.7nF; schematic may show 4n7.\n#8\nCool! Thanks for the info, guys!\nWhat if the schematic reads just 12 for the capacitor (like C1 in the attached schematic)?? I'm having a problem getting it to work. Either my inputs are wrong, my outputs are wrong, or the schematic itself is wrong. I'm assuming the - V coming from R4 is the positive voltage. Would it need more than 9volts (I started low, and worked my way up to 9 volts)\nlow level audio amp 1 transistor.gif\n8 KB\n\t\t\t\t\t\n\t\t\t\t\t· Views: 526\n#9\nI would imagine it means uF or microfarads in this instance. The capacitors shown are polarised. IE there is a + and - pin. The - pin is usualy marked on the capacitor with a big black stripe on the casing.\nVoltage looks to be NEGATIVE voltage\nIs the circuit correct? - Sorry not qualified to answer that one for ya\n#10\nThis circuit is a common emitter amplifier using a pnp transistor, and the voltage on the collector of a pnp is negative relative to the emitter.\nConnect the negative side of your 9V battery to V- and the positive side of the battery to the circuit ground. The circuit as drawn is fine, and you can use 10uF electrolytics in place of the existing 12 (uF) caps shown.\nKevin\nEdited to add additional comment.\n#11\nOh, I see. So that's what the V- means. Thanks\n#12\nHi,\nThe schematic is effectively drawn upside down and that is causing some confusion\nYou should be able to improve on the performance of a single transistor.\nLook up doug self's site for more detailed info on discrete amplifiers. 1 , 2 and 3 transistor versions as well as discrete opamps.\nhttp:\/\/www.dself.dsl.pipex.com\nThere are many other designer's sites to complement that one.\n#13\nNo, the schematic is not drawn upside down, this is a pnp transistor and following normal drawing convention this is the way a simple amplifier circuit would be represented. The only weird thing to most people is that the supply is negative relative to ground. You might find such an amplifier circuit in an old car radio of vehicles with a positive ground for example.\n#14\nI've used this one as a mic preamplifier. It was my first circuit and I was surprised at how good those few cheap parts sounded!\nIt works great if you adapt the circuit's impedances to those of the in- and output devices! But it doesn't work well if you got a high source impedance together with a low next stage impedance!\nHappy diy-ing!\nDominique","attrs_markdown":"[![diyAudio](https:\/\/www.diyaudio.com\/community\/styles\/diy\/diy\/logo.svg)](https:\/\/www.diyaudio.com\/community\/)\n\n[![diyAudio](https:\/\/www.diyaudio.com\/community\/styles\/diy\/diy\/logo.svg)](https:\/\/www.diyaudio.com\/community\/)\n\n- [Forums]()\n  \n  [Forums Home](https:\/\/www.diyaudio.com\/community\/forums\/-\/list)\n  \n  ### Amplifiers\n  - [Solid State](https:\/\/www.diyaudio.com\/community\/forums\/solid-state.4\/)\n  - [Pass Labs](https:\/\/www.diyaudio.com\/community\/forums\/pass-labs.8\/)\n  - [Tubes\/Valves](https:\/\/www.diyaudio.com\/community\/forums\/tubes-valves.5\/)\n  - [Chip Amps](https:\/\/www.diyaudio.com\/community\/forums\/chip-amps.40\/)\n  - [Class D](https:\/\/www.diyaudio.com\/community\/forums\/class-d.49\/)\n  - [Power 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[Parts](https:\/\/www.diyaudio.com\/community\/forums\/parts.13\/)\n- What does the R in resistor value 240R mean?\n\nJavaScript is disabled. 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It may not display this or other websites correctly.  \nYou should upgrade or use an [alternative browser](https:\/\/www.google.com\/chrome\/).\n\n# What does the R in resistor value 240R mean?\n- Thread starter [caxxxxxx](https:\/\/www.diyaudio.com\/community\/members\/caxxxxxx.30059\/)\n- Start date\n  [2005-04-16 8:43 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/)\n\nStatus\n\nNot open for further replies.\n\n[Jump to Latest](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/latest)\n\n[C](https:\/\/www.diyaudio.com\/community\/members\/caxxxxxx.30059\/)\n\n#### [caxxxxxx](https:\/\/www.diyaudio.com\/community\/members\/caxxxxxx.30059\/)\n##### Member\nJoined 2005\n\n[2005-04-16 8:43 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621041)\n\n[\\#1](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621041)\n\n- [2005-04-16 8:43 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621041)\n\n- [\\#1](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621041)\n\nI'm a newbie in the world of DIY electronics, and was wondering where I can get info on what the R means in 240R resistor on a schematic. I know it's probably a simple question, but I am a beginner.\n\n[J](https:\/\/www.diyaudio.com\/community\/members\/jleaman.1479\/)\n\n#### [jleaman](https:\/\/www.diyaudio.com\/community\/members\/jleaman.1479\/)\n##### Member\nJoined 2002\n\n[plus.google.com\/photos\/104656656065604242634\/albums\/5725366675475046257?banner=pwa\\&amp;gpsrc](https:\/\/plus.google.com\/photos\/104656656065604242634\/albums\/5725366675475046257?banner=pwa&amp;gpsrc)\n\n[2005-04-16 8:46 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621112)\n\n[\\#2](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621112)\n\n- [2005-04-16 8:46 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621112)\n\n- [\\#2](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621112)\n\n240R means 240 Ohm : O )\n\n[Z](https:\/\/www.diyaudio.com\/community\/members\/zombie.3770\/)\n\n#### [Zombie](https:\/\/www.diyaudio.com\/community\/members\/zombie.3770\/)\n##### Member\nJoined 2003\n\n[2005-04-16 8:53 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621115)\n\n[\\#3](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621115)\n\n- [2005-04-16 8:53 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621115)\n\n- [\\#3](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621115)\n\n1R8 = 1,8 ohm  \n 10R = 10 ohm  \n 1k2 = 1,2 kohm  \n 12k = 12 kohm  \n 1M = 1 Mohm  \n   \n Get it?![:smash:](https:\/\/files.diyaudio.com\/forums\/images\/smilies\/smash.gif)\n\n[C](https:\/\/www.diyaudio.com\/community\/members\/cpemma.5372\/)\n\n#### [cpemma](https:\/\/www.diyaudio.com\/community\/members\/cpemma.5372\/)\n##### Member\nJoined 2003\n\n[cpemma.co.uk](http:\/\/www.cpemma.co.uk\/)\n\n[2005-04-20 10:50 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624171)\n\n[\\#4](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624171)\n\n- [2005-04-20 10:50 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624171)\n\n- [\\#4](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624171)\n\nThe 'letter marker for decimal point' system was introduced to reduce reading errors on schematics; with resistors using 'R' also means you don't have to remember how the heck to get the ohm symbol ( Ω ) - more info [here (pdf).](http:\/\/www.nutsvolts.com\/PDF_Files\/circuit.pdf)\n\n[P](https:\/\/www.diyaudio.com\/community\/members\/promitheus.49\/)\n\n#### [promitheus](https:\/\/www.diyaudio.com\/community\/members\/promitheus.49\/)\n##### Member\nJoined 2001\n\n[2005-04-20 11:17 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624180)\n\n[\\#5](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624180)\n\n- [2005-04-20 11:17 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624180)\n\n- [\\#5](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624180)\n\nR means resistance and is used instead of the decimal point.  \n The decimal point is sometimes hard to see.\n\n[D](https:\/\/www.diyaudio.com\/community\/members\/dominique.14130\/)\n\n#### [Dominique](https:\/\/www.diyaudio.com\/community\/members\/dominique.14130\/)\n##### Member\nJoined 2004\n\n[2005-04-21 12:35 am](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624222)\n\n[\\#6](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624222)\n\n- [2005-04-21 12:35 am](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624222)\n\n- [\\#6](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624222)\n\nto complicate things here's the info I got on caps ratings:  \n   \n QUICK REFERENCE CHART (Decade values)  \n 1R0 = 1pF 103 = .01uF  \n 100 = 10pF 104 = .1uF  \n 101 = 100pF 105 = 1uF  \n 102 =.001uF 106 = 10uF  \n 1010= Some numbers used on 10 meters\\!  \n   \n I saw that in datasheets too (though you very rarely come across caps smaller than 10pF, so the \"R\" is hardly ever seen on capacitors anyway)  \n   \n Just to say that \"R\" probably means something else than resistance in that code...\n\n[C](https:\/\/www.diyaudio.com\/community\/members\/cpemma.5372\/)\n\n#### [cpemma](https:\/\/www.diyaudio.com\/community\/members\/cpemma.5372\/)\n##### Member\nJoined 2003\n\n[cpemma.co.uk](http:\/\/www.cpemma.co.uk\/)\n\n[2005-04-21 2:16 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624618)\n\n[\\#7](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624618)\n\n- [2005-04-21 2:16 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624618)\n\n- [\\#7](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624618)\n\n> Dominique said:\n> \n> **to complicate things here's the info I got on caps ratings:    QUICK REFERENCE CHART (Decade values)  1R0 = 1pF 103 = .01uF  100 = 10pF 104 = .1uF  101 = 100pF 105 = 1uF  102 =.001uF 106 = 10uF**\n> \n> [Click to expand...]()\n\nThose numbers are usually seen marked on the part rather than in a schematic, especially on small caps. A bit like resistors, the first two give the value, the third the multiplier (number of zeroes), result in picofarads, so 472 = 4,700pf = 4.7nF; schematic may show 4n7.\n\n[C](https:\/\/www.diyaudio.com\/community\/members\/caxxxxxx.30059\/)\n\n#### [caxxxxxx](https:\/\/www.diyaudio.com\/community\/members\/caxxxxxx.30059\/)\n##### Member\nJoined 2005\n\n[2005-04-22 8:21 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625684)\n\n[\\#8](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625684)\n\n- [2005-04-22 8:21 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625684)\n\n- [\\#8](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625684)\n\nCool! Thanks for the info, guys!   \n   \n What if the schematic reads just 12 for the capacitor (like C1 in the attached schematic)?? I'm having a problem getting it to work. Either my inputs are wrong, my outputs are wrong, or the schematic itself is wrong. I'm assuming the - V coming from R4 is the positive voltage. Would it need more than 9volts (I started low, and worked my way up to 9 volts)\n\n#### Attachments\n- [![low level audio amp 1 transistor.gif](https:\/\/www.diyaudio.com\/community\/data\/attachments\/40\/40793-959e907ac86d5b6febe2ff20e056464c.jpg?hash=lZ6QeshtW2)](https:\/\/www.diyaudio.com\/community\/attachments\/low-level-audio-amp-1-transistor-gif.43267\/)\n  low level audio amp 1 transistor.gif\n  \n  8 KB · Views: 526\n\n[B](https:\/\/www.diyaudio.com\/community\/members\/byrd.7198\/)\n\n#### [Byrd](https:\/\/www.diyaudio.com\/community\/members\/byrd.7198\/)\n##### Member\nJoined 2003\n\n[byrd.fotopic.net](http:\/\/byrd.fotopic.net\/)\n\n[2005-04-22 8:59 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625719)\n\n[\\#9](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625719)\n\n- [2005-04-22 8:59 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625719)\n\n- [\\#9](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625719)\n\nI would imagine it means uF or microfarads in this instance. The capacitors shown are polarised. IE there is a + and - pin. The - pin is usualy marked on the capacitor with a big black stripe on the casing.  \n   \n Voltage looks to be NEGATIVE voltage  \n   \n Is the circuit correct? - Sorry not qualified to answer that one for ya\n\n[![kevinkr](https:\/\/www.diyaudio.com\/community\/data\/avatars\/s\/17\/17629.jpg?1638973605)](https:\/\/www.diyaudio.com\/community\/members\/kevinkr.17629\/)\n\n#### [kevinkr](https:\/\/www.diyaudio.com\/community\/members\/kevinkr.17629\/)\n##### Moderator\nJoined 2004\n\n[kta-hifi.net](http:\/\/www.kta-hifi.net\/)\n\n**Paid Member**\n\n[2005-04-22 9:11 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625726)\n\n[\\#10](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625726)\n\n- [2005-04-22 9:11 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625726)\n\n- [\\#10](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625726)\n\nThis circuit is a common emitter amplifier using a pnp transistor, and the voltage on the collector of a pnp is negative relative to the emitter.  \n Connect the negative side of your 9V battery to V- and the positive side of the battery to the circuit ground. The circuit as drawn is fine, and you can use 10uF electrolytics in place of the existing 12 (uF) caps shown.  \n   \n Kevin  \n   \n Edited to add additional comment.\n\n[C](https:\/\/www.diyaudio.com\/community\/members\/caxxxxxx.30059\/)\n\n#### [caxxxxxx](https:\/\/www.diyaudio.com\/community\/members\/caxxxxxx.30059\/)\n##### Member\nJoined 2005\n\n[2005-04-22 10:17 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625771)\n\n[\\#11](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625771)\n\n- [2005-04-22 10:17 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625771)\n\n- [\\#11](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625771)\n\nOh, I see. So that's what the V- means. Thanks\n\n[A](https:\/\/www.diyaudio.com\/community\/members\/andrewt.15587\/)\n\n#### [AndrewT](https:\/\/www.diyaudio.com\/community\/members\/andrewt.15587\/)\n##### R.I.P.\nJoined 2004\n\n[2005-04-23 9:18 am](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-626040)\n\n[\\#12](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-626040)\n\n- [2005-04-23 9:18 am](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-626040)\n\n- [\\#12](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-626040)\n\nHi,  \n The schematic is effectively drawn upside down and that is causing some confusion  \n You should be able to improve on the performance of a single transistor.  \n Look up doug self's site for more detailed info on discrete amplifiers. 1 , 2 and 3 transistor versions as well as discrete opamps. <http:\/\/www.dself.dsl.pipex.com>  \n There are many other designer's sites to complement that one.\n\n[![kevinkr](https:\/\/www.diyaudio.com\/community\/data\/avatars\/s\/17\/17629.jpg?1638973605)](https:\/\/www.diyaudio.com\/community\/members\/kevinkr.17629\/)\n\n#### [kevinkr](https:\/\/www.diyaudio.com\/community\/members\/kevinkr.17629\/)\n##### Moderator\nJoined 2004\n\n[kta-hifi.net](http:\/\/www.kta-hifi.net\/)\n\n**Paid Member**\n\n[2005-04-24 4:21 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-626827)\n\n[\\#13](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-626827)\n\n- [2005-04-24 4:21 pm](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-626827)\n\n- [\\#13](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-626827)\n\nNo, the schematic is not drawn upside down, this is a pnp transistor and following normal drawing convention this is the way a simple amplifier circuit would be represented. The only weird thing to most people is that the supply is negative relative to ground. You might find such an amplifier circuit in an old car radio of vehicles with a positive ground for example.\n\n[D](https:\/\/www.diyaudio.com\/community\/members\/dominique.14130\/)\n\n#### [Dominique](https:\/\/www.diyaudio.com\/community\/members\/dominique.14130\/)\n##### Member\nJoined 2004\n\n[2005-04-25 12:55 am](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-627155)\n\n[\\#14](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-627155)\n\n- [2005-04-25 12:55 am](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-627155)\n\n- [\\#14](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-627155)\n\nI've used this one as a mic preamplifier. It was my first circuit and I was surprised at how good those few cheap parts sounded\\!  \n   \n It works great if you adapt the circuit's impedances to those of the in- and output devices! But it doesn't work well if you got a high source impedance together with a low next stage impedance\\!  \n   \n Happy diy-ing\\!  \n Dominique\n\nStatus\n\nNot open for further replies.\n\nShare:\n\n[Facebook](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#_xfUid-1-1772828852)   [X](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#_xfUid-1-1772828852)   [Bluesky](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#_xfUid-1-1772828852)   [LinkedIn](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#_xfUid-1-1772828852)   [Reddit](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#_xfUid-1-1772828852)   [Pinterest](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#_xfUid-1-1772828852)   [Tumblr](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#_xfUid-1-1772828852)   [WhatsApp](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#_xfUid-1-1772828852)   [Email](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#_xfUid-1-1772828852)   [Link](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#_xfUid-1-1772828852)\n\n- [Home](https:\/\/www.diyaudio.com\/)\n- [Design & Build](https:\/\/www.diyaudio.com\/community\/forums\/-\/list#design-build.75)\n- [Parts](https:\/\/www.diyaudio.com\/community\/forums\/parts.13\/)\n- What does the R in resistor value 240R mean?\n\n[diyAudio Community](https:\/\/www.diyaudio.com\/community\/) [diyAudio Store](https:\/\/diyaudiostore.com\/)\n\n[Gallery](https:\/\/www.diyaudio.com\/community\/media\/) [Archive](https:\/\/www.diyaudio.com\/archive\/) [Articles](https:\/\/www.diyaudio.com\/archive\/articles\/)\n\n- [Theme - Light](https:\/\/www.diyaudio.com\/community\/misc\/style \"Style chooser\")\n- [YYYY-MM-DD \/ 12-hour clock](https:\/\/www.diyaudio.com\/community\/misc\/language \"Language chooser\")\n\n- [Contact us](https:\/\/www.diyaudio.com\/community\/misc\/contact)\n- [Terms and rules](https:\/\/www.diyaudio.com\/community\/help\/terms\/)\n- [Privacy policy](https:\/\/www.diyaudio.com\/community\/help\/privacy-policy\/)\n- [Help](https:\/\/www.diyaudio.com\/community\/help\/)\n- [RSS](https:\/\/www.diyaudio.com\/community\/forums\/-\/index.rss \"RSS\")\n\n[Style and add-ons by Audentio](https:\/\/www.audent.io\/)\n\n[Top](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#top) [Bottom](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/#footer)","attrs_readable_markdown":"- [\\#1](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621041)\n\nI'm a newbie in the world of DIY electronics, and was wondering where I can get info on what the R means in 240R resistor on a schematic. I know it's probably a simple question, but I am a beginner.\n\n- [\\#2](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621112)\n\n240R means 240 Ohm : O )\n\n- [\\#3](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-621115)\n\n1R8 = 1,8 ohm  \n 10R = 10 ohm  \n 1k2 = 1,2 kohm  \n 12k = 12 kohm  \n 1M = 1 Mohm\n\nGet it?![:smash:](https:\/\/files.diyaudio.com\/forums\/images\/smilies\/smash.gif)\n\n- [\\#4](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624171)\n\nThe 'letter marker for decimal point' system was introduced to reduce reading errors on schematics; with resistors using 'R' also means you don't have to remember how the heck to get the ohm symbol ( Ω ) - more info [here (pdf).](http:\/\/www.nutsvolts.com\/PDF_Files\/circuit.pdf)\n\n- [\\#5](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624180)\n\nR means resistance and is used instead of the decimal point.  \n The decimal point is sometimes hard to see.\n\n- [\\#6](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624222)\n\nto complicate things here's the info I got on caps ratings:\n\nQUICK REFERENCE CHART (Decade values)  \n 1R0 = 1pF 103 = .01uF  \n 100 = 10pF 104 = .1uF  \n 101 = 100pF 105 = 1uF  \n 102 =.001uF 106 = 10uF  \n 1010= Some numbers used on 10 meters\\!\n\nI saw that in datasheets too (though you very rarely come across caps smaller than 10pF, so the \"R\" is hardly ever seen on capacitors anyway)\n\nJust to say that \"R\" probably means something else than resistance in that code...\n\n- [\\#7](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-624618)\n\n> Dominique said:\n> \n> **to complicate things here's the info I got on caps ratings:QUICK REFERENCE CHART (Decade values)  1R0 = 1pF 103 = .01uF  100 = 10pF 104 = .1uF  101 = 100pF 105 = 1uF  102 =.001uF 106 = 10uF**\n\nThose numbers are usually seen marked on the part rather than in a schematic, especially on small caps. A bit like resistors, the first two give the value, the third the multiplier (number of zeroes), result in picofarads, so 472 = 4,700pf = 4.7nF; schematic may show 4n7.\n\n- [\\#8](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625684)\n\nCool! Thanks for the info, guys\\!\n\nWhat if the schematic reads just 12 for the capacitor (like C1 in the attached schematic)?? I'm having a problem getting it to work. Either my inputs are wrong, my outputs are wrong, or the schematic itself is wrong. I'm assuming the - V coming from R4 is the positive voltage. Would it need more than 9volts (I started low, and worked my way up to 9 volts)\n\n- [![low level audio amp 1 transistor.gif](https:\/\/www.diyaudio.com\/community\/data\/attachments\/40\/40793-959e907ac86d5b6febe2ff20e056464c.jpg?hash=lZ6QeshtW2)](https:\/\/www.diyaudio.com\/community\/attachments\/low-level-audio-amp-1-transistor-gif.43267\/)\n  low level audio amp 1 transistor.gif\n  \n  8 KB · Views: 526\n\n- [\\#9](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625719)\n\nI would imagine it means uF or microfarads in this instance. The capacitors shown are polarised. IE there is a + and - pin. The - pin is usualy marked on the capacitor with a big black stripe on the casing.\n\nVoltage looks to be NEGATIVE voltage\n\nIs the circuit correct? - Sorry not qualified to answer that one for ya\n\n[![kevinkr](https:\/\/www.diyaudio.com\/community\/data\/avatars\/s\/17\/17629.jpg?1638973605)](https:\/\/www.diyaudio.com\/community\/members\/kevinkr.17629\/)\n\n- [\\#10](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625726)\n\nThis circuit is a common emitter amplifier using a pnp transistor, and the voltage on the collector of a pnp is negative relative to the emitter.  \n Connect the negative side of your 9V battery to V- and the positive side of the battery to the circuit ground. The circuit as drawn is fine, and you can use 10uF electrolytics in place of the existing 12 (uF) caps shown.\n\nKevin\n\nEdited to add additional comment.\n\n- [\\#11](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-625771)\n\nOh, I see. So that's what the V- means. Thanks\n\n- [\\#12](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-626040)\n\nHi,  \n The schematic is effectively drawn upside down and that is causing some confusion  \n You should be able to improve on the performance of a single transistor.  \n Look up doug self's site for more detailed info on discrete amplifiers. 1 , 2 and 3 transistor versions as well as discrete opamps. [http:\/\/www.dself.dsl.pipex.com](http:\/\/www.dself.dsl.pipex.com\/)  \n There are many other designer's sites to complement that one.\n\n[![kevinkr](https:\/\/www.diyaudio.com\/community\/data\/avatars\/s\/17\/17629.jpg?1638973605)](https:\/\/www.diyaudio.com\/community\/members\/kevinkr.17629\/)\n\n- [\\#13](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-626827)\n\nNo, the schematic is not drawn upside down, this is a pnp transistor and following normal drawing convention this is the way a simple amplifier circuit would be represented. The only weird thing to most people is that the supply is negative relative to ground. You might find such an amplifier circuit in an old car radio of vehicles with a positive ground for example.\n\n- [\\#14](https:\/\/www.diyaudio.com\/community\/threads\/what-does-the-r-in-resistor-value-240r-mean.55519\/post-627155)\n\nI've used this one as a mic preamplifier. It was my first circuit and I was surprised at how good those few cheap parts sounded\\!\n\nIt works great if you adapt the circuit's impedances to those of the in- and output devices! But it doesn't work well if you got a high source impedance together with a low next stage impedance\\!\n\nHappy diy-ing\\!  \n Dominique","meta_canonical":null}

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Boilerpipe Text	#1 I'm a newbie in the world of DIY electronics, and was wondering where I can get info on what the R means in 240R resistor on a schematic. I know it's probably a simple question, but I am a beginner. #2 240R means 240 Ohm : O ) #3 1R8 = 1,8 ohm 10R = 10 ohm 1k2 = 1,2 kohm 12k = 12 kohm 1M = 1 Mohm Get it? #4 The 'letter marker for decimal point' system was introduced to reduce reading errors on schematics; with resistors using 'R' also means you don't have to remember how the heck to get the ohm symbol ( Ω ) - more info here (pdf). #5 R means resistance and is used instead of the decimal point. The decimal point is sometimes hard to see. #6 to complicate things here's the info I got on caps ratings: QUICK REFERENCE CHART (Decade values) 1R0 = 1pF 103 = .01uF 100 = 10pF 104 = .1uF 101 = 100pF 105 = 1uF 102 =.001uF 106 = 10uF 1010= Some numbers used on 10 meters! I saw that in datasheets too (though you very rarely come across caps smaller than 10pF, so the "R" is hardly ever seen on capacitors anyway) Just to say that "R" probably means something else than resistance in that code... #7 Dominique said: to complicate things here's the info I got on caps ratings: QUICK REFERENCE CHART (Decade values) 1R0 = 1pF 103 = .01uF 100 = 10pF 104 = .1uF 101 = 100pF 105 = 1uF 102 =.001uF 106 = 10uF Those numbers are usually seen marked on the part rather than in a schematic, especially on small caps. A bit like resistors, the first two give the value, the third the multiplier (number of zeroes), result in picofarads, so 472 = 4,700pf = 4.7nF; schematic may show 4n7. #8 Cool! Thanks for the info, guys! What if the schematic reads just 12 for the capacitor (like C1 in the attached schematic)?? I'm having a problem getting it to work. Either my inputs are wrong, my outputs are wrong, or the schematic itself is wrong. I'm assuming the - V coming from R4 is the positive voltage. Would it need more than 9volts (I started low, and worked my way up to 9 volts) low level audio amp 1 transistor.gif 8 KB · Views: 526 #9 I would imagine it means uF or microfarads in this instance. The capacitors shown are polarised. IE there is a + and - pin. The - pin is usualy marked on the capacitor with a big black stripe on the casing. Voltage looks to be NEGATIVE voltage Is the circuit correct? - Sorry not qualified to answer that one for ya #10 This circuit is a common emitter amplifier using a pnp transistor, and the voltage on the collector of a pnp is negative relative to the emitter. Connect the negative side of your 9V battery to V- and the positive side of the battery to the circuit ground. The circuit as drawn is fine, and you can use 10uF electrolytics in place of the existing 12 (uF) caps shown. Kevin Edited to add additional comment. #11 Oh, I see. So that's what the V- means. Thanks #12 Hi, The schematic is effectively drawn upside down and that is causing some confusion You should be able to improve on the performance of a single transistor. Look up doug self's site for more detailed info on discrete amplifiers. 1 , 2 and 3 transistor versions as well as discrete opamps. http://www.dself.dsl.pipex.com There are many other designer's sites to complement that one. #13 No, the schematic is not drawn upside down, this is a pnp transistor and following normal drawing convention this is the way a simple amplifier circuit would be represented. The only weird thing to most people is that the supply is negative relative to ground. You might find such an amplifier circuit in an old car radio of vehicles with a positive ground for example. #14 I've used this one as a mic preamplifier. It was my first circuit and I was surprised at how good those few cheap parts sounded! It works great if you adapt the circuit's impedances to those of the in- and output devices! But it doesn't work well if you got a high source impedance together with a low next stage impedance! Happy diy-ing! Dominique
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JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding. You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an [alternative browser](https://www.google.com/chrome/). # What does the R in resistor value 240R mean? - Thread starter [caxxxxxx](https://www.diyaudio.com/community/members/caxxxxxx.30059/) - Start date [2005-04-16 8:43 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/) Status Not open for further replies. [Jump to Latest](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/latest) [C](https://www.diyaudio.com/community/members/caxxxxxx.30059/) #### [caxxxxxx](https://www.diyaudio.com/community/members/caxxxxxx.30059/) ##### Member Joined 2005 [2005-04-16 8:43 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621041) [\#1](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621041) - [2005-04-16 8:43 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621041) - [\#1](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621041) I'm a newbie in the world of DIY electronics, and was wondering where I can get info on what the R means in 240R resistor on a schematic. I know it's probably a simple question, but I am a beginner. [J](https://www.diyaudio.com/community/members/jleaman.1479/) #### [jleaman](https://www.diyaudio.com/community/members/jleaman.1479/) ##### Member Joined 2002 [plus.google.com/photos/104656656065604242634/albums/5725366675475046257?banner=pwa\&gpsrc](https://plus.google.com/photos/104656656065604242634/albums/5725366675475046257?banner=pwa&gpsrc) [2005-04-16 8:46 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621112) [\#2](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621112) - [2005-04-16 8:46 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621112) - [\#2](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621112) 240R means 240 Ohm : O ) [Z](https://www.diyaudio.com/community/members/zombie.3770/) #### [Zombie](https://www.diyaudio.com/community/members/zombie.3770/) ##### Member Joined 2003 [2005-04-16 8:53 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621115) [\#3](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621115) - [2005-04-16 8:53 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621115) - [\#3](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621115) 1R8 = 1,8 ohm 10R = 10 ohm 1k2 = 1,2 kohm 12k = 12 kohm 1M = 1 Mohm Get it?![:smash:](https://files.diyaudio.com/forums/images/smilies/smash.gif) [C](https://www.diyaudio.com/community/members/cpemma.5372/) #### [cpemma](https://www.diyaudio.com/community/members/cpemma.5372/) ##### Member Joined 2003 [cpemma.co.uk](http://www.cpemma.co.uk/) [2005-04-20 10:50 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624171) [\#4](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624171) - [2005-04-20 10:50 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624171) - [\#4](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624171) The 'letter marker for decimal point' system was introduced to reduce reading errors on schematics; with resistors using 'R' also means you don't have to remember how the heck to get the ohm symbol ( Ω ) - more info [here (pdf).](http://www.nutsvolts.com/PDF_Files/circuit.pdf) [P](https://www.diyaudio.com/community/members/promitheus.49/) #### [promitheus](https://www.diyaudio.com/community/members/promitheus.49/) ##### Member Joined 2001 [2005-04-20 11:17 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624180) [\#5](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624180) - [2005-04-20 11:17 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624180) - [\#5](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624180) R means resistance and is used instead of the decimal point. The decimal point is sometimes hard to see. [D](https://www.diyaudio.com/community/members/dominique.14130/) #### [Dominique](https://www.diyaudio.com/community/members/dominique.14130/) ##### Member Joined 2004 [2005-04-21 12:35 am](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624222) [\#6](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624222) - [2005-04-21 12:35 am](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624222) - [\#6](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624222) to complicate things here's the info I got on caps ratings: QUICK REFERENCE CHART (Decade values) 1R0 = 1pF 103 = .01uF 100 = 10pF 104 = .1uF 101 = 100pF 105 = 1uF 102 =.001uF 106 = 10uF 1010= Some numbers used on 10 meters\! I saw that in datasheets too (though you very rarely come across caps smaller than 10pF, so the "R" is hardly ever seen on capacitors anyway) Just to say that "R" probably means something else than resistance in that code... [C](https://www.diyaudio.com/community/members/cpemma.5372/) #### [cpemma](https://www.diyaudio.com/community/members/cpemma.5372/) ##### Member Joined 2003 [cpemma.co.uk](http://www.cpemma.co.uk/) [2005-04-21 2:16 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624618) [\#7](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624618) - [2005-04-21 2:16 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624618) - [\#7](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624618) > Dominique said: > > to complicate things here's the info I got on caps ratings: QUICK REFERENCE CHART (Decade values) 1R0 = 1pF 103 = .01uF 100 = 10pF 104 = .1uF 101 = 100pF 105 = 1uF 102 =.001uF 106 = 10uF > > [Click to expand...]() Those numbers are usually seen marked on the part rather than in a schematic, especially on small caps. A bit like resistors, the first two give the value, the third the multiplier (number of zeroes), result in picofarads, so 472 = 4,700pf = 4.7nF; schematic may show 4n7. [C](https://www.diyaudio.com/community/members/caxxxxxx.30059/) #### [caxxxxxx](https://www.diyaudio.com/community/members/caxxxxxx.30059/) ##### Member Joined 2005 [2005-04-22 8:21 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625684) [\#8](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625684) - [2005-04-22 8:21 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625684) - [\#8](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625684) Cool! Thanks for the info, guys! What if the schematic reads just 12 for the capacitor (like C1 in the attached schematic)?? I'm having a problem getting it to work. Either my inputs are wrong, my outputs are wrong, or the schematic itself is wrong. I'm assuming the - V coming from R4 is the positive voltage. Would it need more than 9volts (I started low, and worked my way up to 9 volts) #### Attachments - [![low level audio amp 1 transistor.gif](https://www.diyaudio.com/community/data/attachments/40/40793-959e907ac86d5b6febe2ff20e056464c.jpg?hash=lZ6QeshtW2)](https://www.diyaudio.com/community/attachments/low-level-audio-amp-1-transistor-gif.43267/) low level audio amp 1 transistor.gif 8 KB · Views: 526 [B](https://www.diyaudio.com/community/members/byrd.7198/) #### [Byrd](https://www.diyaudio.com/community/members/byrd.7198/) ##### Member Joined 2003 [byrd.fotopic.net](http://byrd.fotopic.net/) [2005-04-22 8:59 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625719) [\#9](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625719) - [2005-04-22 8:59 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625719) - [\#9](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625719) I would imagine it means uF or microfarads in this instance. The capacitors shown are polarised. IE there is a + and - pin. The - pin is usualy marked on the capacitor with a big black stripe on the casing. Voltage looks to be NEGATIVE voltage Is the circuit correct? - Sorry not qualified to answer that one for ya [![kevinkr](https://www.diyaudio.com/community/data/avatars/s/17/17629.jpg?1638973605)](https://www.diyaudio.com/community/members/kevinkr.17629/) #### [kevinkr](https://www.diyaudio.com/community/members/kevinkr.17629/) ##### Moderator Joined 2004 [kta-hifi.net](http://www.kta-hifi.net/) Paid Member [2005-04-22 9:11 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625726) [\#10](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625726) - [2005-04-22 9:11 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625726) - [\#10](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625726) This circuit is a common emitter amplifier using a pnp transistor, and the voltage on the collector of a pnp is negative relative to the emitter. Connect the negative side of your 9V battery to V- and the positive side of the battery to the circuit ground. The circuit as drawn is fine, and you can use 10uF electrolytics in place of the existing 12 (uF) caps shown. Kevin Edited to add additional comment. [C](https://www.diyaudio.com/community/members/caxxxxxx.30059/) #### [caxxxxxx](https://www.diyaudio.com/community/members/caxxxxxx.30059/) ##### Member Joined 2005 [2005-04-22 10:17 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625771) [\#11](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625771) - [2005-04-22 10:17 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625771) - [\#11](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625771) Oh, I see. So that's what the V- means. Thanks [A](https://www.diyaudio.com/community/members/andrewt.15587/) #### [AndrewT](https://www.diyaudio.com/community/members/andrewt.15587/) ##### R.I.P. Joined 2004 [2005-04-23 9:18 am](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-626040) [\#12](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-626040) - [2005-04-23 9:18 am](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-626040) - [\#12](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-626040) Hi, The schematic is effectively drawn upside down and that is causing some confusion You should be able to improve on the performance of a single transistor. Look up doug self's site for more detailed info on discrete amplifiers. 1 , 2 and 3 transistor versions as well as discrete opamps. <http://www.dself.dsl.pipex.com> There are many other designer's sites to complement that one. [![kevinkr](https://www.diyaudio.com/community/data/avatars/s/17/17629.jpg?1638973605)](https://www.diyaudio.com/community/members/kevinkr.17629/) #### [kevinkr](https://www.diyaudio.com/community/members/kevinkr.17629/) ##### Moderator Joined 2004 [kta-hifi.net](http://www.kta-hifi.net/) Paid Member [2005-04-24 4:21 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-626827) [\#13](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-626827) - [2005-04-24 4:21 pm](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-626827) - [\#13](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-626827) No, the schematic is not drawn upside down, this is a pnp transistor and following normal drawing convention this is the way a simple amplifier circuit would be represented. The only weird thing to most people is that the supply is negative relative to ground. You might find such an amplifier circuit in an old car radio of vehicles with a positive ground for example. [D](https://www.diyaudio.com/community/members/dominique.14130/) #### [Dominique](https://www.diyaudio.com/community/members/dominique.14130/) ##### Member Joined 2004 [2005-04-25 12:55 am](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-627155) [\#14](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-627155) - [2005-04-25 12:55 am](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-627155) - [\#14](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-627155) I've used this one as a mic preamplifier. It was my first circuit and I was surprised at how good those few cheap parts sounded\! It works great if you adapt the circuit's impedances to those of the in- and output devices! But it doesn't work well if you got a high source impedance together with a low next stage impedance\! Happy diy-ing\! Dominique Status Not open for further replies. 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Readable Markdown	- [\#1](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621041) I'm a newbie in the world of DIY electronics, and was wondering where I can get info on what the R means in 240R resistor on a schematic. I know it's probably a simple question, but I am a beginner. - [\#2](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621112) 240R means 240 Ohm : O ) - [\#3](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-621115) 1R8 = 1,8 ohm 10R = 10 ohm 1k2 = 1,2 kohm 12k = 12 kohm 1M = 1 Mohm Get it?![:smash:](https://files.diyaudio.com/forums/images/smilies/smash.gif) - [\#4](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624171) The 'letter marker for decimal point' system was introduced to reduce reading errors on schematics; with resistors using 'R' also means you don't have to remember how the heck to get the ohm symbol ( Ω ) - more info [here (pdf).](http://www.nutsvolts.com/PDF_Files/circuit.pdf) - [\#5](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624180) R means resistance and is used instead of the decimal point. The decimal point is sometimes hard to see. - [\#6](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624222) to complicate things here's the info I got on caps ratings: QUICK REFERENCE CHART (Decade values) 1R0 = 1pF 103 = .01uF 100 = 10pF 104 = .1uF 101 = 100pF 105 = 1uF 102 =.001uF 106 = 10uF 1010= Some numbers used on 10 meters\! I saw that in datasheets too (though you very rarely come across caps smaller than 10pF, so the "R" is hardly ever seen on capacitors anyway) Just to say that "R" probably means something else than resistance in that code... - [\#7](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-624618) > Dominique said: > > to complicate things here's the info I got on caps ratings:QUICK REFERENCE CHART (Decade values) 1R0 = 1pF 103 = .01uF 100 = 10pF 104 = .1uF 101 = 100pF 105 = 1uF 102 =.001uF 106 = 10uF Those numbers are usually seen marked on the part rather than in a schematic, especially on small caps. A bit like resistors, the first two give the value, the third the multiplier (number of zeroes), result in picofarads, so 472 = 4,700pf = 4.7nF; schematic may show 4n7. - [\#8](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625684) Cool! Thanks for the info, guys\! What if the schematic reads just 12 for the capacitor (like C1 in the attached schematic)?? I'm having a problem getting it to work. Either my inputs are wrong, my outputs are wrong, or the schematic itself is wrong. I'm assuming the - V coming from R4 is the positive voltage. Would it need more than 9volts (I started low, and worked my way up to 9 volts) - [![low level audio amp 1 transistor.gif](https://www.diyaudio.com/community/data/attachments/40/40793-959e907ac86d5b6febe2ff20e056464c.jpg?hash=lZ6QeshtW2)](https://www.diyaudio.com/community/attachments/low-level-audio-amp-1-transistor-gif.43267/) low level audio amp 1 transistor.gif 8 KB · Views: 526 - [\#9](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625719) I would imagine it means uF or microfarads in this instance. The capacitors shown are polarised. IE there is a + and - pin. The - pin is usualy marked on the capacitor with a big black stripe on the casing. Voltage looks to be NEGATIVE voltage Is the circuit correct? - Sorry not qualified to answer that one for ya [![kevinkr](https://www.diyaudio.com/community/data/avatars/s/17/17629.jpg?1638973605)](https://www.diyaudio.com/community/members/kevinkr.17629/) - [\#10](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625726) This circuit is a common emitter amplifier using a pnp transistor, and the voltage on the collector of a pnp is negative relative to the emitter. Connect the negative side of your 9V battery to V- and the positive side of the battery to the circuit ground. The circuit as drawn is fine, and you can use 10uF electrolytics in place of the existing 12 (uF) caps shown. Kevin Edited to add additional comment. - [\#11](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-625771) Oh, I see. So that's what the V- means. Thanks - [\#12](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-626040) Hi, The schematic is effectively drawn upside down and that is causing some confusion You should be able to improve on the performance of a single transistor. Look up doug self's site for more detailed info on discrete amplifiers. 1 , 2 and 3 transistor versions as well as discrete opamps. [http://www.dself.dsl.pipex.com](http://www.dself.dsl.pipex.com/) There are many other designer's sites to complement that one. [![kevinkr](https://www.diyaudio.com/community/data/avatars/s/17/17629.jpg?1638973605)](https://www.diyaudio.com/community/members/kevinkr.17629/) - [\#13](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-626827) No, the schematic is not drawn upside down, this is a pnp transistor and following normal drawing convention this is the way a simple amplifier circuit would be represented. The only weird thing to most people is that the supply is negative relative to ground. You might find such an amplifier circuit in an old car radio of vehicles with a positive ground for example. - [\#14](https://www.diyaudio.com/community/threads/what-does-the-r-in-resistor-value-240r-mean.55519/post-627155) I've used this one as a mic preamplifier. It was my first circuit and I was surprised at how good those few cheap parts sounded\! It works great if you adapt the circuit's impedances to those of the in- and output devices! But it doesn't work well if you got a high source impedance together with a low next stage impedance\! Happy diy-ing\! Dominique
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