Philips N3G82VT Car Radio - UK Vintage Radio Repair and Restoration Discussion Forum

Hermit6345 · 2nd Apr 2012, 7:20 pm

I found this poor old thing in an "antiques/junk" emporium last Friday. It was absolutely filthy but I have never worked on these hybrid sets with four 12 volt HT valves plus a Germanium power transistor for audio output. This model is similar in lineup to other car radios from Philips in this period viz 1959/60.

The first thing I had to do was to check whether it was positive or negative earth. As supplied they are set to positive earth but can be converted by moving a number of wires on a couple of tag strips.

It was positive earth. 12 volts connected up, current limit on PSU set low and switch on. Got a dial lamp and a couple of valves with lit heaters. The valve heaters are in a series parallel configuration in this set, so I wiggled the valves in their sockets, then a dose of de-oxit to each of the valve holders and we had all four valves lit. The EF98 driver seemed to be very loose in its socket though. The radio was now playing but the volume was not what I expected, only about 0.5 watt. I was still concerned about the inability of the B7G holder to hold the EF98 valve and more volume could be obtained by wiggling the valve in its socket. Guess what? yes, the socket was one of the McMurdo type so beloved of battery portable makers. Closer examination showed at least four of the bifurcated pin holders were broken. I was going to replace just the broken pins but could not find a suitable donor socket in my junk box. Therefore I had to bite the bullet, drill out the rivets on the socket and do a bit of keyhole surgery to remove everything on the existing socket and finally extract the old McMurdo effort. The whole job took about two hours in all.

The EF98 was now nice and tight in its socket. Switched on again and after a few seconds was greeted with a very lively radio with over 2 watts output at full volume. I set up the OC19 collector current to be 325mA or as close as I could get to it.

Removed the knobs with the Volume pot refusing first to release its grub screw and then refusing to come off the volume pot spindle. Easing oil finally did the trick and rust on the spindle was found to be the culprit.

Knobs, chromium plated bright-work and backing plate all removed and carefully cleaned. The chromium plated surround re-acted positively to some very fine wire wool soaked in Brasso. Knobs cleaned with Amberclens and then polished. Tuning pointer was a bit faded so a tiny amount of White paint applied and the whole lot re-assembled.

Black crackle casing was cleaned and rejuvenated with some black paint rubbed in to the crackle finish on the casing.

A new n-line fuse holder was fitted as the original was missing and a new chocolate block fitted to the audio output cable. Did a quick check of alignment but it all seemed to be peaked anyway.

Not sure where I am going to use it as it's over 50 years old now and in any case I don't have a car from that era. I just did it for the experience.

Steve_P · 3rd Apr 2012, 12:00 am

Interesting beasts are car radios aren't they. Not many about now of that kind which is a shame. Valves like EF98 aren't too common either.

Cheers,

Steve P.

bobbyball · 3rd Apr 2012, 10:17 pm

Nice job there....

Robert

Hermit6345 · 3rd Apr 2012, 11:39 pm

Yes, the sets are very interesting Steve. It's all upside down, with the valve anodes in effect connected to chassis potential. It's also pretty cramped in there. I like the way that they use the triode part of the first ECH83 as an audio amplifier and the other half as an RF amplifier. I would imagine that 12 volt HT valves including the EF98 would only have been used in sets produced after those sets with vibratory power units and before fully transistorised radios. Quite a small period. Though I read that these series of valves were selected from batches of ordinary valves. The ones that worked best with 12 volts HT were marked as such. It's all permeability tuned as well, which is an advantage. The down side is that they use those peculiar Philips tubular trimmers where you unwind wire off a former to reduce capacitance but is difficult to wind it back on again. The 170A used similar ones..

Thanks for your kind words Robert.

Ian.

Trevor · 1st Jul 2012, 3:00 pm

I have 2 similar sets Does any 1 have a schematic for these The 1 that works seams to be a great little radio
regards trev

tri-comp · 1st Jul 2012, 9:23 pm

Hi Trevor,

Put this into Google: Philips N3G82VT

rgds,

/tri-comp

PaulR · 3rd Jul 2012, 12:27 pm

Very nice job there. A friend of mine has a couple of these sets but I have put off repairing them due to their odd configuration. At least there isn't a vibrator to worry about.

As a matter of interest I was once told that a pad of aluminiun foil polishes chromium very well. I have a classic car with chrome bumpers and I find that it does indeed work if you can stand the noise which sounds like someone scraping their fingernail on a blackboard.

Paul

2nd Apr 2012, 7:20 pm	#1
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Philips N3G82VT Car Radio I found this poor old thing in an "antiques/junk" emporium last Friday. It was absolutely filthy but I have never worked on these hybrid sets with four 12 volt HT valves plus a Germanium power transistor for audio output. This model is similar in lineup to other car radios from Philips in this period viz 1959/60. The first thing I had to do was to check whether it was positive or negative earth. As supplied they are set to positive earth but can be converted by moving a number of wires on a couple of tag strips. It was positive earth. 12 volts connected up, current limit on PSU set low and switch on. Got a dial lamp and a couple of valves with lit heaters. The valve heaters are in a series parallel configuration in this set, so I wiggled the valves in their sockets, then a dose of de-oxit to each of the valve holders and we had all four valves lit. The EF98 driver seemed to be very loose in its socket though. The radio was now playing but the volume was not what I expected, only about 0.5 watt. I was still concerned about the inability of the B7G holder to hold the EF98 valve and more volume could be obtained by wiggling the valve in its socket. Guess what? yes, the socket was one of the McMurdo type so beloved of battery portable makers. Closer examination showed at least four of the bifurcated pin holders were broken. I was going to replace just the broken pins but could not find a suitable donor socket in my junk box. Therefore I had to bite the bullet, drill out the rivets on the socket and do a bit of keyhole surgery to remove everything on the existing socket and finally extract the old McMurdo effort. The whole job took about two hours in all. The EF98 was now nice and tight in its socket. Switched on again and after a few seconds was greeted with a very lively radio with over 2 watts output at full volume. I set up the OC19 collector current to be 325mA or as close as I could get to it. Removed the knobs with the Volume pot refusing first to release its grub screw and then refusing to come off the volume pot spindle. Easing oil finally did the trick and rust on the spindle was found to be the culprit. Knobs, chromium plated bright-work and backing plate all removed and carefully cleaned. The chromium plated surround re-acted positively to some very fine wire wool soaked in Brasso. Knobs cleaned with Amberclens and then polished. Tuning pointer was a bit faded so a tiny amount of White paint applied and the whole lot re-assembled. Black crackle casing was cleaned and rejuvenated with some black paint rubbed in to the crackle finish on the casing. A new n-line fuse holder was fitted as the original was missing and a new chocolate block fitted to the audio output cable. Did a quick check of alignment but it all seemed to be peaked anyway. Not sure where I am going to use it as it's over 50 years old now and in any case I don't have a car from that era. I just did it for the experience. Attached Thumbnails

3rd Apr 2012, 12:00 am	#2
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Philips N3G82VT Car Radio Interesting beasts are car radios aren't they. Not many about now of that kind which is a shame. Valves like EF98 aren't too common either. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

3rd Apr 2012, 10:17 pm	#3
bobbyball Octode Join Date: Jul 2011 Location: Stockport, Greater Manchester Posts: 1,215	Re: Philips N3G82VT Car Radio Nice job there.... Robert

3rd Apr 2012, 11:39 pm	#4
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Re: Philips N3G82VT Car Radio Yes, the sets are very interesting Steve. It's all upside down, with the valve anodes in effect connected to chassis potential. It's also pretty cramped in there. I like the way that they use the triode part of the first ECH83 as an audio amplifier and the other half as an RF amplifier. I would imagine that 12 volt HT valves including the EF98 would only have been used in sets produced after those sets with vibratory power units and before fully transistorised radios. Quite a small period. Though I read that these series of valves were selected from batches of ordinary valves. The ones that worked best with 12 volts HT were marked as such. It's all permeability tuned as well, which is an advantage. The down side is that they use those peculiar Philips tubular trimmers where you unwind wire off a former to reduce capacitance but is difficult to wind it back on again. The 170A used similar ones.. Thanks for your kind words Robert. Ian.

1st Jul 2012, 3:00 pm	#5
Trevor Octode Join Date: Aug 2006 Location: Stoke-on-Trent, Staffordshire, UK. Posts: 1,082	Re: Philips N3G82VT Car Radio I have 2 similar sets Does any 1 have a schematic for these The 1 that works seams to be a great little radio regards trev

1st Jul 2012, 9:23 pm	#6
tri-comp Heptode Join Date: Oct 2008 Location: Aalborg, Denmark Posts: 903	Re: Philips N3G82VT Car Radio Hi Trevor, Put this into Google: Philips N3G82VT rgds, /tri-comp

3rd Jul 2012, 12:27 pm	#7
PaulR Dekatron Join Date: Oct 2003 Location: Southport Lancashire, UK. Posts: 3,236	Re: Philips N3G82VT Car Radio Very nice job there. A friend of mine has a couple of these sets but I have put off repairing them due to their odd configuration. At least there isn't a vibrator to worry about. As a matter of interest I was once told that a pad of aluminiun foil polishes chromium very well. I have a classic car with chrome bumpers and I find that it does indeed work if you can stand the noise which sounds like someone scraping their fingernail on a blackboard. Paul