UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Ferguson 3214 (3 speed 4 track mono) - "ingenious" modification to record level meter

dazzlevision · 12th Aug 2019, 7:48 am

I have now traced out the circuit.

The audio signal from the anode of the third preamp stage (triode of ECL86) is connected to the neon, via a 500kOhm variable preset series resistor, which is adjusted to give the desired neon striking level. The other end of the neon goes to chassis.

I have seen this type of record level indication method used in a GEC (and Sobell) branded tape recorder from the 1960s, fitted with the BSR TD2 tape deck.

I have a working meter from a later production recorder, which uses the same Thorn deck and electronics, but the meter is a German made “Bertram” type, which has proven to be much more reliable over time, so I’ll fit that and set up as per the service manual procedure.

Apart from the meter, the recorder is basically working, but will need a mechanical service, a new counter belt, plus a few electronic component changes (as there are a lot of Erie PCB type carbon composition resistors, plus a few suspect electrolytics). Thorn have at least used a carbon film type for the anode load of the first preamp stage (ECC83).

The date of manufacture is around September 1965 (printed on the Plessey multi-section HT smoothing “can” electrolytic).

12th Aug 2019, 7:48 am	#4
dazzlevision Dekatron Join Date: Sep 2003 Location: Near Swindon, North Wiltshire, UK. Posts: 3,612	Re: Ferguson 3214 (3 speed 4 track mono) - "ingenious" modification to record level m I have now traced out the circuit. The audio signal from the anode of the third preamp stage (triode of ECL86) is connected to the neon, via a 500kOhm variable preset series resistor, which is adjusted to give the desired neon striking level. The other end of the neon goes to chassis. I have seen this type of record level indication method used in a GEC (and Sobell) branded tape recorder from the 1960s, fitted with the BSR TD2 tape deck. I have a working meter from a later production recorder, which uses the same Thorn deck and electronics, but the meter is a German made “Bertram” type, which has proven to be much more reliable over time, so I’ll fit that and set up as per the service manual procedure. Apart from the meter, the recorder is basically working, but will need a mechanical service, a new counter belt, plus a few electronic component changes (as there are a lot of Erie PCB type carbon composition resistors, plus a few suspect electrolytics). Thorn have at least used a carbon film type for the anode load of the first preamp stage (ECC83). The date of manufacture is around September 1965 (printed on the Plessey multi-section HT smoothing “can” electrolytic).