UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Akai GX4000-D reel-to-reel speed problem

Radio Wrangler · 21st Jan 2023, 2:52 pm

It could be the increasing tension from the drag brake on the supply spool as the tape diameter on that spool diminishes. This can expose problems with hardened pinch wheels and pinch wheel springs. The Akai 4000 family use a capstan sleeve to get 7.5 ips, which means the pinch wheel position varies a bit and 7.5 ips gets more pressure than 3.75 ips.

Another possibility is the slipping clutch on the take-up spool drive grabbing, but that would be most troublesome at the beginning of playing a tape.

So check feed tension, check pinch wheel condition, check pinch wheel pressure, check take-up tension.

It's probably long past clean and re-lubrication time.

David

21st Jan 2023, 2:52 pm	#2
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,901	Re: Akai GX4000-D reel-to-reel speed problem It could be the increasing tension from the drag brake on the supply spool as the tape diameter on that spool diminishes. This can expose problems with hardened pinch wheels and pinch wheel springs. The Akai 4000 family use a capstan sleeve to get 7.5 ips, which means the pinch wheel position varies a bit and 7.5 ips gets more pressure than 3.75 ips. Another possibility is the slipping clutch on the take-up spool drive grabbing, but that would be most troublesome at the beginning of playing a tape. So check feed tension, check pinch wheel condition, check pinch wheel pressure, check take-up tension. It's probably long past clean and re-lubrication time. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done