UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

Pieter H · 1st Jul 2018, 10:20 pm

Hi David,
Thanks for the Tuner pictures!
The VHF one is obviously the AT7639/22, which did have the Memomatic channel pre-set memory as well as the VHF-UHF switch on top (with the large spring clearly visible in the pictures). This is by itself interesting, because the Philips sets of the period (1964) did not have this switch yet. Having the built-on switch also meant that the UHF IF signal was fed into the VHF tuner where it used the PCF80 pentode section - in VHF mode used as mixer - as IF amplifier. This is probably the explanation of poor UHF performance in many early (Philips) sets.
The AT7639 in your DR101 was produced in Eindhoven (as identified by the code A04 on the label, "A" referring to Eindhoven). So it looks that the Decca sets of this period, with Decca being considered a third party, obtained more modern tuners from Eindhoven than the AT7639/21 version developed and produced in Croydon.

The UHF tuner, with the PC88 and PC86 valves and no PCB on top is almost certainly the AT6360/02. Pity the lable is gone.

Cheers, Pieter

1st Jul 2018, 10:20 pm	#36
Pieter H Tetrode Join Date: Sep 2017 Location: Waalre, Netherlands Posts: 67	Re: Decca DR101 dual standard TV Hi David, Thanks for the Tuner pictures! The VHF one is obviously the AT7639/22, which did have the Memomatic channel pre-set memory as well as the VHF-UHF switch on top (with the large spring clearly visible in the pictures). This is by itself interesting, because the Philips sets of the period (1964) did not have this switch yet. Having the built-on switch also meant that the UHF IF signal was fed into the VHF tuner where it used the PCF80 pentode section - in VHF mode used as mixer - as IF amplifier. This is probably the explanation of poor UHF performance in many early (Philips) sets. The AT7639 in your DR101 was produced in Eindhoven (as identified by the code A04 on the label, "A" referring to Eindhoven). So it looks that the Decca sets of this period, with Decca being considered a third party, obtained more modern tuners from Eindhoven than the AT7639/21 version developed and produced in Croydon. The UHF tuner, with the PC88 and PC86 valves and no PCB on top is almost certainly the AT6360/02. Pity the lable is gone. Cheers, Pieter