[Barks67]

Thanks for all the replies everybody.

This machine has been in storage and not used for the last 10 years.
The issue of off spec electrolytic caps is a possibility as a result of this.
It used to belong to Steve Wright of Grange Hill, Brookside and Holly Oaks fame.

I think it must be a power issue. The connector board for all the record/replay boards should be +18v according to the service manual schematic so I'll start there - recapping the power supply may be the first step.

I tried again bringing in signals very low peaking about -7dB and it 'kind of' behaved better.

Originally Posted by jamesperrett

That's very unlikely - normal signals don't really get weaker with head wear although high frequencies may reduce and head to tape contact is worse.

Good point - thanks

Originally Posted by TIMTAPE

I agree with James that this looks like a power supply issue. Probably a weak power supply which would explain the pulsing (hum?) in the repro stages when it drops out of regulation. I'd be checking that the relevent regulated voltages are within tolerances at all times.

Also as James said, wear in repro heads doesn't normally cause a gradual drop off in output. Most of the head's output remains essentially constant throughout the life of the head but excepting for mechanical tape to head contact issues, the playback high frequency response actually improves with head wear right up to the point where the head gap opens and fails. Then there is a sharp drop off in response and the head has no more useful life.

Thanks Tim