Philips L6X38T "Antoinette". - UK Vintage Radio Repair and Restoration Discussion Forum

FERNSEH · 15th Jun 2020, 4:08 pm

A discussion about a similar receiver appeared in the forum in 2008:

https://www.vintage-radio.net/forum/...ad.php?t=30757

The Philips L6X38T which is the subject of todays discussion was brought into the shop quite a long time ago. Last week I summoned up the courage to attempt to repair it.
For starters the audio amplifier needed attention. Voltages on the transistors were way out, no volts at the collector of the audio driver transistor TS9, (AC125) that turned out to be the earphone switch needing adjustment. In this set the collector of the driver transistor can be switched to the driver transformer or the earphone, it's just a matter of pressing a button at the back of the cabinet which then allows the earphone cable to be released. Press another button and the earphone lead will be re-spooled into the cabinet and the driver transformer is reconnected to the transistor.
That part put right still no activity from the loudspeaker, more contact troubles. The extension speaker socket has contacts which break when the external speaker is plugged in. Easy fix, wired the internal speaker direct to the output transformer.
Now there is a faint hiss coming from the loudspeaker but no stations coming in. Move on to the IF amplifier and I find two transistors TS6 and TS5 have base to emitter short circuits. There's evidence that these transistors are not the originals being AF121s, the factory fitted transistor were AF126s. Replacements will be fitted and the results will be reported later today.
What is of concern, what is causing the transistors to fail?

DFWB.

FERNSEH · 16th Jun 2020, 10:43 am

IF amplifier transistors TS5 and TS6 replaced. Hiss level has increased proving that there is some activity from the front end of the receiver. The AM/FM switch has contact issues. Still no stations coming in.

DFWB.

OldTechFan96 · 16th Jun 2020, 1:27 pm

I have a Philips set from 1968 which looks to have identical switchbanks. They were the cause of the set being dead on all bands. They look to be an interesting attempt at miniaturisation.

The 'stem' that moves up and down can be removed and the metal contact fingers can be retentioned, giving a better contact.

The stems are made from a thin metal shim which is covered in plastic. In my radio, the plastic was cracking in places and needed to be reglued.

OldTechFan96 · 16th Jun 2020, 2:03 pm

Here are some photographs of the switches and an example of a stem.

FERNSEH · 16th Jun 2020, 3:27 pm

Hi OldTechFan96,
Thanks for posting up the pictures of the switches. The first switch to receive attention will be the AM/FM switch. FM stations were heard today so we know the tuner is OK. The three stage IF amplifier is working which means the AM mixer will be OK as well. The separate AM oscillator transistor is OK.
Would be a shame to give up on the set having got so far with the repair.

DFWB.

15th Jun 2020, 4:08 pm	#1
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Philips L6X38T "Antoinette". A discussion about a similar receiver appeared in the forum in 2008: https://www.vintage-radio.net/forum/...ad.php?t=30757 The Philips L6X38T which is the subject of todays discussion was brought into the shop quite a long time ago. Last week I summoned up the courage to attempt to repair it. For starters the audio amplifier needed attention. Voltages on the transistors were way out, no volts at the collector of the audio driver transistor TS9, (AC125) that turned out to be the earphone switch needing adjustment. In this set the collector of the driver transistor can be switched to the driver transformer or the earphone, it's just a matter of pressing a button at the back of the cabinet which then allows the earphone cable to be released. Press another button and the earphone lead will be re-spooled into the cabinet and the driver transformer is reconnected to the transistor. That part put right still no activity from the loudspeaker, more contact troubles. The extension speaker socket has contacts which break when the external speaker is plugged in. Easy fix, wired the internal speaker direct to the output transformer. Now there is a faint hiss coming from the loudspeaker but no stations coming in. Move on to the IF amplifier and I find two transistors TS6 and TS5 have base to emitter short circuits. There's evidence that these transistors are not the originals being AF121s, the factory fitted transistor were AF126s. Replacements will be fitted and the results will be reported later today. What is of concern, what is causing the transistors to fail? DFWB. Attached Thumbnails Last edited by FERNSEH; 15th Jun 2020 at 4:13 pm.

16th Jun 2020, 10:43 am	#2
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips L6X38T "Antoinette". IF amplifier transistors TS5 and TS6 replaced. Hiss level has increased proving that there is some activity from the front end of the receiver. The AM/FM switch has contact issues. Still no stations coming in. DFWB. Attached Thumbnails

16th Jun 2020, 1:27 pm	#3
OldTechFan96 Octode Join Date: Jul 2017 Location: Newcastle Upon Tyne, Tyne & Wear, UK. Posts: 1,186	Re: Philips L6X38T "Antoinette". I have a Philips set from 1968 which looks to have identical switchbanks. They were the cause of the set being dead on all bands. They look to be an interesting attempt at miniaturisation. The 'stem' that moves up and down can be removed and the metal contact fingers can be retentioned, giving a better contact. The stems are made from a thin metal shim which is covered in plastic. In my radio, the plastic was cracking in places and needed to be reglued.

16th Jun 2020, 2:03 pm	#4
OldTechFan96 Octode Join Date: Jul 2017 Location: Newcastle Upon Tyne, Tyne & Wear, UK. Posts: 1,186	Re: Philips L6X38T "Antoinette". Here are some photographs of the switches and an example of a stem. Attached Thumbnails

16th Jun 2020, 3:27 pm	#5
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips L6X38T "Antoinette". Hi OldTechFan96, Thanks for posting up the pictures of the switches. The first switch to receive attention will be the AM/FM switch. FM stations were heard today so we know the tuner is OK. The three stage IF amplifier is working which means the AM mixer will be OK as well. The separate AM oscillator transistor is OK. Would be a shame to give up on the set having got so far with the repair. DFWB.