Philips L3G23T Transistor Radio - UK Vintage Radio Repair and Restoration Discussion Forum

Trannytuner · 2nd Apr 2019, 8:37 pm

Hello All
Hope someone can help me, I have acquired a Philips L3G23T radio, and on trying it for the first time, I connected two pp3 9v batteries to the connectors, positive to positive, negative to negative, etc but one of the batteries seems to be shorting, is there a special way to connect the batteries to this radio??
I will be surprised if it is in working order, as it uses the infamous Mullard AF117 transistors, but it would be a great help, if the batteries were connected correctly.
Any ideas anyone?

Here are some photos of the set, which is in very good condition.

rojosuiza · 2nd Apr 2019, 9:16 pm

If the voltage at the AF117 transistors is not correct, they are probably faulty. You may begin with taking away the shield connection; sometimes the radio comes back to life halfheartedly. The AF127 is a good replacement.

Trannytuner · 2nd Apr 2019, 9:27 pm

Hi

I just get an error message with that link, sorry.

poppydog · 2nd Apr 2019, 9:37 pm

I had 1 the other day that someone had taped the wires together in wrong order, resulting in a short. If you take neg lead from If board and pos lead from output board and connect them to your battery and the remaining leads to the other battery you should be ok
poppydog

crackle · 2nd Apr 2019, 9:44 pm

Yes it is important which leads you pair together, they should be taped in pairs, obviously the tape has come loose. The manufacturers service manual, available from above, shows the way to connect them.

Mike

Station X · 2nd Apr 2019, 9:45 pm

The service information for this radio is available here:-

https://www.service-data.com/product...96/6133/m14696

Philips210 · 2nd Apr 2019, 9:48 pm

Hi Trannytuner.

The two PP7 9V batteries are effectively connected in series via the wavechange switch. The circuit diagram can be found up top https://www.service-data.com/section.php/6133/1/l3g23t

Regards,
Symon

Trannytuner · 3rd Apr 2019, 11:27 am

Many thanks to everyone who replied to my post, very much appreciated.
Now that I have the batteries connected correctly, the set now produces a very faint hiss, would I be correct in saying the Mullard AF117s and electrolytic capacitors will need to be replaced? I don't have any AF127 transistors, as has been suggested, but I have some Russian GT322B transistors, would these be a suitable replacement?
I hope I haven't damaged any other components, by connecting the batteries wrongly.
On another tack, does anyone have a link to a PP7 9v battery scan? as these batteries are like gold dust, the PP3 9v batteries don't look very nice in a vintage radio

Mike. Watterson · 3rd Apr 2019, 12:37 pm

As long as the Russian transistors are PNP and IF/RF types (Ft = maybe 60), not low frequency Audio (Ft maybe 1MHz) they'll work.
Electrolytics might reform. Unless they are dried out. A cheap uncased eBay Chinese multi-test with ZIF socket and graphics LCD is good. You only need to unsolder one end and have a couple of short patch leads with sprung hooks or croc clips that have a breadboard pin for the ZIF socket. They will weed out bad caps. Power the cap for a while and then discharge before testing.

jayceebee · 3rd Apr 2019, 12:50 pm

I used to have one of those in the 60s, nice to see one in such good condition. Apart from listening to the radio I also used it to boost the output of one of those early 3" reel Japanese tape recorders. To use an external input you press down both MW and LW buttons.

Good luck with it.

John.

Trannytuner · 3rd Apr 2019, 1:57 pm

Hi Mike
Many thanks for the info, also regarding the device for testing the electrolytics.
I think the Russian GT322B transistors might be ok, I have found a Utube video uploaded by Radiocruncher, who uses these Russian transistors to repair a Stella portable radio.
https://www.youtube.com/watch?v=uNUUaj6M-cs
Hi John
I'll give your suggestion a go if I get it working
Cheers

paulsherwin · 3rd Apr 2019, 4:44 pm

The GT322Bs will be fine.

Herald1360 · 3rd Apr 2019, 5:27 pm

Just be careful with their pinout- it's different from both AF117 and AF127. You may need a bit of small bore sleeving (PTFE is ideal but silicon rubber or even PVC stripped from flex will do) since a fair bit of leg crossing is required and the legs aren't very long!

Trannytuner · 3rd Apr 2019, 5:50 pm

Many thanks Paul and Herald1360 for the info and advice regarding replacing the transistors.

Another question I was going to ask, before I order capacitors, is the value and voltage very critical for the electrolytics, as the original types are probably no longer available.

paulsherwin · 3rd Apr 2019, 6:18 pm

The voltage rating should be the same or higher than the originals. The value isn't critical and you should select the nearest modern value to the originals (so replace 50uF with 47uF).

rojosuiza · 3rd Apr 2019, 9:10 pm

Cut the shield connection of the AF117 first, to see what that produces...

Trannytuner · 4th Apr 2019, 9:41 am

Hello Rojosuiza
I have already cut the shield wires to both AF117 transistors, no joy I'm afraid
I think they will have to be removed and replaced, along with the electrolytic caps when I am in there, many thanks though for your help.

Trannytuner · 4th Apr 2019, 10:01 am

My sincere thanks to everyone for their help and advice, very much appreciated as always
It's down to me now, hopefully I can get the radio back in working order, as these type of Philips radios have very good sensitivity and audio.

Moderator can you please close the thread, thank you.

2nd Apr 2019, 8:37 pm	#1
Trannytuner Tetrode Join Date: Mar 2009 Location: Nr. Whitsome, Duns, Berwickshire UK. Posts: 56	Philips L3G23T Transistor Radio Hello All Hope someone can help me, I have acquired a Philips L3G23T radio, and on trying it for the first time, I connected two pp3 9v batteries to the connectors, positive to positive, negative to negative, etc but one of the batteries seems to be shorting, is there a special way to connect the batteries to this radio?? I will be surprised if it is in working order, as it uses the infamous Mullard AF117 transistors, but it would be a great help, if the batteries were connected correctly. Any ideas anyone? Here are some photos of the set, which is in very good condition. Attached Thumbnails

2nd Apr 2019, 9:16 pm	#2
rojosuiza Tetrode Join Date: Mar 2018 Location: Amsterdam, Netherlands Posts: 68	Re: Philips L3G23T Transistor Radio If the voltage at the AF117 transistors is not correct, they are probably faulty. You may begin with taking away the shield connection; sometimes the radio comes back to life halfheartedly. The AF127 is a good replacement. Last edited by Station X; 2nd Apr 2019 at 9:43 pm. Reason: Forum rule compliance.

2nd Apr 2019, 9:27 pm	#3
Trannytuner Tetrode Join Date: Mar 2009 Location: Nr. Whitsome, Duns, Berwickshire UK. Posts: 56	Re: Philips L3G23T Transistor Radio Hi I just get an error message with that link, sorry.

2nd Apr 2019, 9:37 pm	#4
poppydog Banned Join Date: Oct 2015 Location: Cornwall, UK. Posts: 849	Re: Philips L3G23T Transistor Radio I had 1 the other day that someone had taped the wires together in wrong order, resulting in a short. If you take neg lead from If board and pos lead from output board and connect them to your battery and the remaining leads to the other battery you should be ok poppydog

2nd Apr 2019, 9:44 pm	#5
crackle Rest in Peace Join Date: Mar 2011 Location: Basildon, Essex, UK. Posts: 4,100	Re: Philips L3G23T Transistor Radio Yes it is important which leads you pair together, they should be taped in pairs, obviously the tape has come loose. The manufacturers service manual, available from above, shows the way to connect them. Mike

2nd Apr 2019, 9:45 pm	#6
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Philips L3G23T Transistor Radio The service information for this radio is available here:- https://www.service-data.com/product...96/6133/m14696 __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

2nd Apr 2019, 9:48 pm	#7
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,579	Re: Philips L3G23T Transistor Radio Hi Trannytuner. The two PP7 9V batteries are effectively connected in series via the wavechange switch. The circuit diagram can be found up top https://www.service-data.com/section.php/6133/1/l3g23t Regards, Symon

3rd Apr 2019, 11:27 am	#8
Trannytuner Tetrode Join Date: Mar 2009 Location: Nr. Whitsome, Duns, Berwickshire UK. Posts: 56	Re: Philips L3G23T Transistor Radio Many thanks to everyone who replied to my post, very much appreciated. Now that I have the batteries connected correctly, the set now produces a very faint hiss, would I be correct in saying the Mullard AF117s and electrolytic capacitors will need to be replaced? I don't have any AF127 transistors, as has been suggested, but I have some Russian GT322B transistors, would these be a suitable replacement? I hope I haven't damaged any other components, by connecting the batteries wrongly. On another tack, does anyone have a link to a PP7 9v battery scan? as these batteries are like gold dust, the PP3 9v batteries don't look very nice in a vintage radio

3rd Apr 2019, 12:37 pm	#9
Mike. Watterson Heptode Join Date: Dec 2014 Location: Limerick, Ireland. Posts: 901	Re: Philips L3G23T Transistor Radio As long as the Russian transistors are PNP and IF/RF types (Ft = maybe 60), not low frequency Audio (Ft maybe 1MHz) they'll work. Electrolytics might reform. Unless they are dried out. A cheap uncased eBay Chinese multi-test with ZIF socket and graphics LCD is good. You only need to unsolder one end and have a couple of short patch leads with sprung hooks or croc clips that have a breadboard pin for the ZIF socket. They will weed out bad caps. Power the cap for a while and then discharge before testing.

3rd Apr 2019, 12:50 pm	#10
jayceebee Heptode Join Date: Jun 2007 Location: Durham, County Durham, UK. Posts: 640	Re: Philips L3G23T Transistor Radio I used to have one of those in the 60s, nice to see one in such good condition. Apart from listening to the radio I also used it to boost the output of one of those early 3" reel Japanese tape recorders. To use an external input you press down both MW and LW buttons. Good luck with it. John.

3rd Apr 2019, 1:57 pm	#11
Trannytuner Tetrode Join Date: Mar 2009 Location: Nr. Whitsome, Duns, Berwickshire UK. Posts: 56	Re: Philips L3G23T Transistor Radio Hi Mike Many thanks for the info, also regarding the device for testing the electrolytics. I think the Russian GT322B transistors might be ok, I have found a Utube video uploaded by Radiocruncher, who uses these Russian transistors to repair a Stella portable radio. https://www.youtube.com/watch?v=uNUUaj6M-cs Hi John I'll give your suggestion a go if I get it working Cheers

3rd Apr 2019, 4:44 pm	#12
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,967	Re: Philips L3G23T Transistor Radio The GT322Bs will be fine.

3rd Apr 2019, 5:27 pm	#13
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Philips L3G23T Transistor Radio Just be careful with their pinout- it's different from both AF117 and AF127. You may need a bit of small bore sleeving (PTFE is ideal but silicon rubber or even PVC stripped from flex will do) since a fair bit of leg crossing is required and the legs aren't very long! __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

3rd Apr 2019, 5:50 pm	#14
Trannytuner Tetrode Join Date: Mar 2009 Location: Nr. Whitsome, Duns, Berwickshire UK. Posts: 56	Re: Philips L3G23T Transistor Radio Many thanks Paul and Herald1360 for the info and advice regarding replacing the transistors. Another question I was going to ask, before I order capacitors, is the value and voltage very critical for the electrolytics, as the original types are probably no longer available.

3rd Apr 2019, 6:18 pm	#15
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,967	Re: Philips L3G23T Transistor Radio The voltage rating should be the same or higher than the originals. The value isn't critical and you should select the nearest modern value to the originals (so replace 50uF with 47uF).

3rd Apr 2019, 9:10 pm	#16
rojosuiza Tetrode Join Date: Mar 2018 Location: Amsterdam, Netherlands Posts: 68	Re: Philips L3G23T Transistor Radio Cut the shield connection of the AF117 first, to see what that produces...

4th Apr 2019, 9:41 am	#17
Trannytuner Tetrode Join Date: Mar 2009 Location: Nr. Whitsome, Duns, Berwickshire UK. Posts: 56	Re: Philips L3G23T Transistor Radio Hello Rojosuiza I have already cut the shield wires to both AF117 transistors, no joy I'm afraid I think they will have to be removed and replaced, along with the electrolytic caps when I am in there, many thanks though for your help.

4th Apr 2019, 10:01 am	#18
Trannytuner Tetrode Join Date: Mar 2009 Location: Nr. Whitsome, Duns, Berwickshire UK. Posts: 56	Re: Philips L3G23T Transistor Radio My sincere thanks to everyone for their help and advice, very much appreciated as always It's down to me now, hopefully I can get the radio back in working order, as these type of Philips radios have very good sensitivity and audio. Moderator can you please close the thread, thank you.