External RGB video adapter from DB-23 female (input) to DE-15F (output, VGA) for Amiga computers.

Compatible with GBS-82xx and OSSC.

DB-23 female connectors are available at https://shareconn.aliexpress.com/store/1102063255?spm=a2g0o.detail.1000007.1.13df5ecbuQuVyp

3D printable Enclosure designed by Ben Gleeson.

https://www.thingiverse.com/thing:6528063

Main features:

• Active buffer for H- and V- sync. + limiting resistors for overload protection
• THS7316 video amp for a perfect RGB equalization and filtering (100% jail bars removal)
• Jumper for selection of H- (default) or Composite sync, for example for GBS-82xx, OSSC (VGA pin 13)
• KEY/PWR VGA pin 9: optional 5V/100mA available on the output port for JP-21(Japanese scart) cables and EDID EEPROM chip
• Improved shielding and reduced ground noise
• Compact design and minimal bill of materials list

Note:

PCB Thickness should be 1.2 mm.

This is NOT a scan doubler.

It fixes the flicker but keeps the original scan frequency unchanged.

Anyhow the adaptor works when connected to 15KHz video monitors such as BenQ, etc.

The "Shield" test point should be soldered to the DB-23 metal chassis using a thick wire.

VGA cable is suggested to fit an EMI / RF noise filter (toroid/ferrite) on each end.

Default setup: R2, R3 100 ohm / R10 not mounted / jumper closed to HSYNC

Tested with:

• BenQ LCD Monitor G2420HD (ET-0027-B) October 2009 Rev. 00-132-BA [VGA]
• MITSUBISHI LCD Monitor RDT1955 [VGA]
• UGREEN 11614 VGA Extension Cable [length 6 ft / 183 cm]
• Sony Trinitron CRT Monitor PVM-9045Q [RGB + SYNC]
• RS 790-2805 Straight 75Ω RF Adapter BNC Plug to RCA Sockets [250MHz]
• GBS-8200 and 8220
• OSSC
• SukkoPera's Rämixx500, Commodore Amiga 500/+, 600, 1000, CDTV, CD32, 2000, 1200, 4000