| Circuit | Category | Date Added | OK? | Votes | |
| GSM-900 Mobile Jammer Book (PDF compressed with WinRAR) | Telephone | Aug 01, 2024 |  | -2 |
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| Portable GSM900 Cellular Phone Jammer | Telephone | Aug 01, 2024 |  | 1 |
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| High Power 800 MHz/AMPS Cellular Phone Jammer | Telephone | Aug 01, 2024 |  | 0 |
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| Cellular Phone Jammer. Ver 2 circuit diagram | Telephone | Aug 01, 2024 |  | 0 |
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| Portable AMPS Cellular Phone Jammer | Telephone | Aug 01, 2024 |  | 2 |
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| Portable AMPS Cellular Phone Jammer - Dual Purpose | Telephone | Aug 01, 2024 |  | -1 |
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| PCS Phone Jammer circuit diagram | Telephone | Aug 01, 2024 |  | 0 |
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| Portable PCS Cellular Phone Jammer circuit schematic | Telephone | Aug 01, 2024 |  | 0 |
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| PCS Cellular Phone Jammer circuit schematic | Telephone | Aug 01, 2024 |  | 2 |
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| GBPPR Cellular Phone Jammer Exciter schematic diagram | Telephone | Aug 01, 2024 |  | 1 |
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| Cellular Phone Jammer RF Amplifier circuit diagram | Telephone | Aug 01, 2024 |  | 0 |
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| Homebrew P2JBZ-style cellular / mobile phone jammer circuit | Telephone | Aug 01, 2024 |  | 0 |
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| FM Telephone Bug | Telephone | |  | 0 |
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| Cellular Phone calling Detector | Telephone | Sep 17, 2024 |  | -1 |
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| Simple Phone Tap circuit diagram | Telephone | Aug 12, 2024 |  | -2 |
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| Telephone Hold Button circuit | Telephone | Aug 12, 2024 |  | -1 |
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| Telephone recorder to record phone conversations automatically | Telephone | Aug 12, 2024 |  | -1 |
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| Cellular Phone calling Detector | Telephone | Aug 12, 2024 |  | 0 |
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| Phone line indicator | Telephone | Sep 17, 2024 |  | 0 |
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| Isolated Telephone Interface | Telephone | Aug 12, 2024 |  | 0 |
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| Telephone Record Control using 2N4360, 2N2222 and 2N2102 | Telephone | Aug 12, 2024 |  | 0 |
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| Phone In Use Indicator circuit diagram | Telephone | Sep 17, 2024 |  | 1 |
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| Phone "Hold" With Music | Telephone | Aug 12, 2024 |  | -1 |
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| Simple speakerphone | Telephone | Aug 12, 2024 |  | 0 |
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| High Quality Intercom using LM380 amplifier IC | Telephone | Aug 12, 2024 |  | 0 |
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| Soft Musical Telephone Ringer | Telephone | Aug 12, 2024 |  | 0 |
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| Telephone amplifier | Telephone | Aug 12, 2024 |  | -3 |
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| Cut Phone Line Detector | Telephone | Aug 12, 2024 |  | 0 |
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| Telephone line monitor | Telephone | Aug 12, 2024 |  | 0 |
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| Phone Busy Indicator | Telephone | Aug 12, 2024 |  | -1 |
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| Ringing Phone Light Flasher using optocoupler and relay | Telephone | Aug 12, 2024 |  | 0 |
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| Telephone Circuit: Music On Hold | Telephone | Oct 03, 2024 |  | 0 |
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| Incoming call indicator (ZIP file) | Telephone | Jan 26, 2025 |  | 0 |
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| Telephone line simulator ideal for testing phone interface projects | Telephone | May 24, 2024 |  | 0 |
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| Self-powered phone messenger based on a PIC16C819 microcontroller | Telephone | May 24, 2024 |  | 0 |
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| Phone call interceptor to stop unsolicited phone calls | Telephone | May 16, 2024 |  | 0 |
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| Telephone call screener with voice | Telephone | May 24, 2024 |  | 1 |
|
| Single-Wire-Telephones for caves and mines | Telephone | Mar 03, 2025 |  | 0 |
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| Simple alarm with telephone dialler interface | Telephone | Mar 27, 2024 |  | 1 |
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| Telephone line simulator | Telephone | Mar 05, 2025 |  | 2 |
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| Home made PBX / PABX | Telephone | Jun 17, 2024 |  | 1 |
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| Ringing Phone Light Flasher | Telephone | Sep 01, 2024 |  | 0 |
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| Phone Busy Indicator | Telephone | Sep 01, 2024 |  | 0 |
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| FM Telephone Bug | Telephone | Sep 01, 2024 |  | 0 |
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| Cut Phone Line Detector | Telephone | Sep 01, 2024 |  | 0 |
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| Simple Phone Tap Circuit | Telephone | Sep 01, 2024 |  | 0 |
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| Telephone Hold Button | Telephone | Sep 01, 2024 |  | 0 |
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| Telephone Recorder | Telephone | Sep 01, 2024 |  | 0 |
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| Remote Telephone Bell Ringer | Telephone | Sep 01, 2024 |  | 0 |
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| Build your own radio controlled switch from a cordless telephone | Telephone | Nov 16, 2024 |  | 0 |
|
| 1-line telephone status indicator powered from a 3V battery (PDF) | Telephone | Jan 26, 2025 |  | 0 |
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| Line in use indicator that handles two independent phone lines (PDF) | Telephone | Jan 26, 2025 |  | 0 |
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| 4-line telephone status indicator that is polarity independent (PDF) | Telephone | Jan 26, 2025 |  | 0 |
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| Cellular Phone calling Detector | Telephone | |  | 0 |
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| Cellular Phone calling detector (detects RF field) | Telephone | Feb 21, 2025 |  | 0 |
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| Telephone music on hold interface | Telephone | Feb 21, 2025 |  | 0 |
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| Soft musical telephone ringer | Telephone | Feb 21, 2025 |  | 0 |
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| Telephone amplifier | Telephone | Feb 21, 2025 |  | 1 |
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| Telephone line monitor | Telephone | Feb 21, 2025 |  | 0 |
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| Cut telephone line detector | Telephone | Feb 21, 2025 |  | 0 |
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| FM telephone line bug transmitter (88MHz to 94MHz) | Telephone | Feb 21, 2025 |  | 0 |
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| Telephone privacy adapter | Telephone | Jan 26, 2025 |  | 1 |
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| Telephone ringing circuits | Telephone | Jan 26, 2025 |  | 0 |
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| Simple circuit to connect telephone equipment to audio mixer | Telephone | Jan 26, 2025 |  | 1 |
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| Universal telephone hold | Telephone | Jan 26, 2025 |  | 0 |
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| Talking phone dial monitor (PDF) | Telephone | Jan 26, 2025 |  | -1 |
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| Simple Skype VoIP analog adapter | Telephone | Sep 10, 2024 |  | 0 |
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| Simple intercom circuit diagram | Telephone | Oct 25, 2024 |  | -1 |
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| Assorted telephone circuits (ring generator, in-use indicator, audio interface) | Telephone | Mar 18, 2024 |  | -1 |
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| Cut phone line detector | Telephone | Jan 08, 2025 |  | 0 |
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| DSL / ADSL phone line filter | Telephone | |  | 0 |
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| Greek telecard reader | Telephone | Apr 17, 2024 |  | 0 |
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| Isolated Telephone Interface (phone tap) for tape recorder, PC sound card etc | Telephone | Sep 21, 2024 |  | -1 |
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| High power mobile phone Jammer circuit | Telephone | Jun 28, 2024 |  | -3 |
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