I bought this Philips 172 on ebay last week . I wasn't planning on starting on it anytime soon but I noticed a friend had one and I started asking questions and one thing lead to another.
The front was very rough so I enlisted my limited spray painting talents lol thats after a full recap.
How do you get such good sound out of a 4 inch speaker.

Negative feedback on the audio likely helps where used. However 172L has none off of the output secondary & is listed as having a Rola 5C?

Marcc it is a Rola. I'm not sure if its 4 inch or 5 but its a real nice sounding set.
Gotta admit though philips are very good at getting you to act like a contortionist lol. The speaker is seperate from the chassis but hardwired in and the wire is about 3 inches too short plus the antennae wire to the foil in the top is the same and you have to reach in to undo the catch for the dial cover. There were quite a few blue words coming from me then lol.

Yeah some Philips sets are just terrible for access, especially the ones where the dial is screwed into the front of the case, instead of being part of the chassis.

Philips also came up with some of the most convoluted dial string arrangements.

One essential is haemostats, minimum of two. That is not only as they make good heatsinks, but you can get things unsoldered with them (and not get fingers burnt) and navigate parts in and out of some really awkward spots.

Rola 5C is 5" rated at 2.5 Watts. Likely RMS. That was the most common speaker used. 6" & bigger is even better. 132L here has a 6" out of a Mitsubishi car door. Due to some Goose drilling a hole to replace the speaker transformer; put the bit through the cone in such a way that it wrecked it.

While it should not matter in an AC situation: I normally ground the speaker negative where grounding of the speaker Voice Coil is shown.

In a DC situation the polarity of the speaker is correct when the cone is ejected.

Do note that where the dial is detached, it is important that the dial is mechanically aligned first (sometimes marked: "set pointer here" on the dial and /or chassis.). Then you use the trimmers etc to bring the frequency to the pointer.

Photos uploaded.

This one actually came up really good with a lick of paint and a polish. Incidentally if any of you guys need a reprint of the dial face of this beaut little set just email me and I have it on pdf.

Ah, now I see the photos, I realised that I have a 172. The case is very light grey, almost off white.

Note the nifty permeability tuning using the same can and formers as the IFTs....

Photo uploaded to Post 9.

Looks Good Carl.

Thanks Brad.

The paint job came up really good. Very smart looking now.