JVC KM-F250: Difference between revisions
Add KM-F250E front and rear photos from NextArchive to images field (via update-page on MediaWiki MCP Server) |
Wikilink RM-P250 references to new JVC RM-P250 page (via update-page on MediaWiki MCP Server) |
||
| (5 intermediate revisions by 2 users not shown) | |||
| Line 4: | Line 4: | ||
|device_type=Frame synchronizer | |device_type=Frame synchronizer | ||
|image_main=JVC KM-F250U front.webp | |image_main=JVC KM-F250U front.webp | ||
|images=JVC KM-F250U rear.webp | |images=JVC KM-F250U rear.webp, JVC KM-F250U boards.webp, JVC KM-F250U service manual 1.webp, JVC KM-F250U service manual 2.webp, JVC KM-F250U service manual 3.webp, JVC KM-F250U service manual 4.webp, JVC KM-F250U service manual 5.webp, JVC KM-F250U service manual 6.webp, JVC KM-F250U service manual 7.webp, JVC KM-F250U service manual 8.webp, JVC KM-F250U service manual 9.webp, JVC KM-F250U service manual 10.webp, JVC KM-F250U service manual 11.webp | ||
|features=Full-frame time base correction, frame synchronization, dropout compensation (DOC), field freeze and frame freeze, multi-format signal/standard transcoding, genlock via external reference input, CCIR Rec. 601 (4:2:2) processing at 13.5 MHz 8-bit quantization, RS-170A compliant (NTSC models), 1 MB frame memory, proc amp controls (video level, chroma level, U-V balance, setup level — each switchable variable/unity), H position adjustment (±7 µsec), Y/C timing adjustment (±1 µsec), optional RM-P250 remote control unit, EIA 19" rack mountable | |suppress_gallery=yes | ||
|features=Full-frame time base correction, frame synchronization, dropout compensation (DOC), field freeze and frame freeze, multi-format signal/standard transcoding, genlock via external reference input, CCIR Rec. 601 (4:2:2) processing at 13.5 MHz 8-bit quantization, RS-170A compliant (NTSC models), 1 MB frame memory, proc amp controls (video level, chroma level, U-V balance, setup level — each switchable variable/unity), H position adjustment (±7 µsec), Y/C timing adjustment (±1 µsec), optional [[JVC RM-P250|RM-P250]] remote control unit, EIA 19" rack mountable | |||
|description=The JVC KM-F250 is a professional rack-mountable frame synchronizer with integrated full-frame time base correction, originally marketed by JVC's Professional Products division. Though officially designated a "frame synchronizer," the unit performs full-frame TBC processing conforming to CCIR Recommendation 601 at 13.5 MHz, 8-bit 4:2:2 sampling, effectively making it a multi-purpose TBC suitable for professional video production and archival workflows. | |description=The JVC KM-F250 is a professional rack-mountable frame synchronizer with integrated full-frame time base correction, originally marketed by JVC's Professional Products division. Though officially designated a "frame synchronizer," the unit performs full-frame TBC processing conforming to CCIR Recommendation 601 at 13.5 MHz, 8-bit 4:2:2 sampling, effectively making it a multi-purpose TBC suitable for professional video production and archival workflows. | ||
The KM-F250 accepts composite (VBS), Y/C separate, and analog component (Y/R-Y/B-Y) video inputs. A loopthrough reference sync (black burst/genlock) input is provided for synchronizing output timing to external equipment, along with a dedicated DOC (dropout compensator) RF carrier input for use with VTRs that provide an RF output. The unit provides two composite video outputs, component outputs, Y/C separate outputs, and four sync reference outputs (ADV SYNC for VTR servo lock, REF SYNC composite sync, REF SC color subcarrier, and REF BB black burst). | The KM-F250 accepts composite (VBS), Y/C separate, and analog component (Y/R-Y/B-Y) video inputs. A loopthrough reference sync (black burst/genlock) input is provided for synchronizing output timing to external equipment, along with a dedicated DOC (dropout compensator) RF carrier input for use with VTRs that provide an RF output. The unit provides two composite video outputs, component outputs, Y/C separate outputs, and four sync reference outputs (ADV SYNC for VTR servo lock, REF SYNC composite sync, REF SC color subcarrier, and REF BB black burst). | ||
The unit includes comprehensive proc amp controls behind the front panel: video (Y) level, chroma level, U-V balance, and setup level — each with a variable/unity switch allowing ±3 dB adjustment (±10% for setup). An H position control allows output horizontal timing adjustment within ±7 µsec, and a Y/C timing control adjusts chroma-to-luminance phase within ±1 µsec. A chroma advance switch advances the chroma output by 1H with respect to luminance when enabled. All front-panel controls can be disabled via a LOCAL/REMOTE switch when using the optional RM-P250 remote control unit. | The unit includes comprehensive proc amp controls behind the front panel: video (Y) level, chroma level, U-V balance, and setup level — each with a variable/unity switch allowing ±3 dB adjustment (±10% for setup). An H position control allows output horizontal timing adjustment within ±7 µsec, and a Y/C timing control adjusts chroma-to-luminance phase within ±1 µsec. A chroma advance switch advances the chroma output by 1H with respect to luminance when enabled. All front-panel controls can be disabled via a LOCAL/REMOTE switch when using the optional [[JVC RM-P250]] remote control unit. | ||
The unit features field freeze and frame freeze functions, useful for still-frame capture in production environments. | The unit features field freeze and frame freeze functions, useful for still-frame capture in production environments. | ||
Internally, the KM-F250 comprises ten circuit boards: RL (relay/bypass switching), CN (connector interface), MT (mounting/interconnect), VIDEO (analog signal processing), MEMORY (digital TBC/frame memory with A/D and D/A conversion), SG (sync generator/SSG), PS (switching power supply producing +12V, −12V, and +5V), REG (voltage regulator converting ±12V to ±9V for video circuits), SUB (subsidiary functions), and PB DET (playback detection).<ref name="service-manual">[[:Document:JVC KM-F250E Service Manual]] — JVC service manual No. 6455 for the KM-F250E. Contains circuit descriptions, adjustment procedures, exploded views, parts lists, and schematic diagrams.</ref> | |||
Internally, the KM-F250 comprises ten circuit boards: RL (relay/bypass switching), CN (connector interface), MT (mounting/interconnect), VIDEO (analog signal processing), MEMORY (digital TBC/frame memory with A/D and D/A conversion), SG (sync generator/SSG), PS (switching power supply producing +12V, −12V, and +5V), REG (voltage regulator converting ±12V to ±9V for video circuits), SUB (subsidiary functions), and PB DET (playback detection).<ref name="service-manual" /> | |||
The KM-F250 is relatively obscure compared to competing TBCs from FOR-A, DataVideo, and Snell & Wilcox, but is encountered in both US broadcast facilities and European archival environments. | The KM-F250 is relatively obscure compared to competing TBCs from FOR-A, DataVideo, and Snell & Wilcox, but is encountered in both US broadcast facilities and European archival environments. | ||
| Line 173: | Line 167: | ||
|link_url=https://www.next-archive.com/product/jvc-km-f250e/ | |link_url=https://www.next-archive.com/product/jvc-km-f250e/ | ||
}} | }} | ||
== | == Variants == | ||
The KM-F250 was produced in several regional variants with significant differences in Y/C signal handling and power supply configuration: | |||
* '''KM-F250U''' — NTSC variant for the US market (120V, 60Hz). Y/C uses a [[Hirose 7-pin DUB]] connector supporting both S-VHS (3.58 MHz) and U-matic DUB (688 kHz) modes, selectable via internal switches behind the front panel.<ref name="bcs-listing">[https://www.broadcaststore.com/store/model_detail.cfm?id=7814 BroadcastStore.com — "JVC KM-F250U TBC &/or Frame Synchronizer"] — US broadcast equipment dealer listing confirming KM-F250U model designation.</ref><ref name="reddit-kmf250u">[https://www.reddit.com/r/VIDEOENGINEERING/comments/1erdlcu/my_jvc_kmf250_frame_synchronizertime_base/ Reddit r/VIDEOENGINEERING — "My JVC KM-F250 Frame Synchronizer/Time Base Corrector"] — Owner photos of a KM-F250U unit showing front panel, rear I/O, and internal components.</ref> | |||
* '''KM-F250E''' — European PAL variant (100–240V, 50/60Hz). Y/C uses a 7-pin DIN connector (with included 7P-to-BNC adapter cable). Supports Y/C 443 at 4.43 MHz (PAL S-VHS), Y/C 924 at 924 kHz (hi-band U-VCR), and Y/C 629 at 629 kHz (VHS). Output Y/C format is selectable via a rear-panel switch (443/924/629), while input Y/C format is set via an internal select pin.<ref name="service-manual" /> | |||
* '''KM-F250EG''' — European PAL variant (230V, 50Hz) | |||
The European variants accept PAL input and can output NTSC 4.43 (pseudo-NTSC with PAL subcarrier frequency), functioning as a basic standards transcoder. The unit was designed for use with consumer and semi-professional video systems including S-VHS, VHS, U-matic, and other formats. | |||
<gallery> | <gallery> | ||
File:JVC KM-F250E front.jpg|JVC KM-F250E front panel (European PAL variant) | File:JVC KM-F250E front.jpg|JVC KM-F250E front panel (European PAL variant) | ||
File:JVC KM-F250E rear.jpg|JVC KM-F250E rear panel (European PAL variant) | File:JVC KM-F250E rear.jpg|JVC KM-F250E rear panel (European PAL variant) | ||
</gallery> | </gallery> | ||
== Photos == | |||
{{EveryCRT gallery|heights=120}} | |||
== Signal Specifications == | == Signal Specifications == | ||
| Line 266: | Line 271: | ||
== See Also == | == See Also == | ||
* [[JVC RM-P250]] — Optional wired remote control unit | |||
* [[:Category:Frame synchronizers|Frame synchronizers]] | * [[:Category:Frame synchronizers|Frame synchronizers]] | ||
* [[:Category:Time base correctors and frame synchronizers|Time base correctors and frame synchronizers]] | * [[:Category:Time base correctors and frame synchronizers|Time base correctors and frame synchronizers]] | ||
