Philips car radio tuning scale poser

[Rusty Gordini]

Good evening,

This is my first post, so I hope I'm posting in the correct section.

I have a 1978 Opel cars brochure which features a GM-branded Philips MW/LW radio in the accessories section. I've looked through this brochure many times, but the other evening I noticed that the tuning scale is like no other I have seen:

The medium waveband is 90 - 550 metres, and the long waveband is 960 - 2000 metres.

I just wondered whether anyone can throw any light on this.

Many thanks.

['LIVEWIRE?']

I'm puzzled by that radio, Rusty. In my time as a service engineer I repaired several examples of a similar model, but they all had the usual MW & LW bands, from about 190 to 550M and 1100 to 2000M., so why the MW coverage on this version should extend down to 90M (3.33Mhz) is beyond me. This would cover the amateur 'top Band' (160M) and maybe one of the Tropical bands. Could it be that this radio was sold in countries where those frequencies were/are used?

[Biggles]

Is it posssible that the radio picture was produced with a bit of artistic licence for the brochure? Maybe the radios actually fitted looked like that but with the more normal tuning scale, and the design studio didn't care too much if the scale was accurate. To most potential car buyers it probably wouldn't be noticed. Is the radio spec listed anywhere as to coverage/audio power output etc? If the frequency coverage listed matches up with the picture then it's more likely to be genuine. I have never come across a car radio with such wide coverage.
Alan.

[Rusty Gordini]

Originally Posted by 'LIVEWIRE?'

I'm puzzled by that radio, Rusty. In my time as a service engineer I repaired several examples of a similar model, but they all had the usual MW & LW bands, from about 190 to 550M and 1100 to 2000M., so why the MW coverage on this version should extend down to 90M (3.33Mhz) is beyond me. This would cover the amateur 'top Band' (160M) and maybe one of the Tropical bands. Could it be that this radio was sold in countries where those frequencies were/are used?

Hello LIVEWIRE?,thanks for replying.

Yup, it's an odd one. Although a UK-produced brochure, it's from a German manufacturer. You might therefore expect to see some German-spec equipment or other content, but the radio featured is certainly not European specification.

As you say, it's an extraordinary breadth of MW coverage; I'm now wondering whether the unit featured might, in fact, be a pre-production mock-up of some sort.

Originally Posted by Biggles

Is it posssible that the radio picture was produced with a bit of artistic licence for the brochure? Maybe the radios actually fitted looked like that but with the more normal tuning scale, and the design studio didn't care too much if the scale was accurate. To most potential car buyers it probably wouldn't be noticed. Is the radio spec listed anywhere as to coverage/audio power output etc? If the frequency coverage listed matches up with the picture then it's more likely to be genuine. I have never come across a car radio with such wide coverage.
Alan.

I'm beginning to think you might be right there. It's just a photo in the accessories section of an all-model range brochure, with no technical specs at all.

[Radio Wrangler]

I was once given a Philips car radio which had a few switched shortwave bands on it. It was not working and I went looking for service data.

The set was branded Philips. I had the thing in my hand and the folk at CES could read all the numbers on it. They asked Philips. Philips said there was no such model. But there it was, full of Philips components. This was all long before the internet.

The set got scrapped as not worth the effort of unravelling it the hard way.

I learned some years afterwards that it had been brought from South Africa, and may have been exported to there at a time when such trade was politically, um, insensitive.

It looks like the people creating your brochure grabbed a set of the right family but the wrong market for their photoshoot, or nobbled an existing photo... Unless General Motors saw a market in German trawler owners!

David

[Rusty Gordini]

Thanks David, that's interesting (and yes, although the internet has its flaws, it's made gathering useful information a whole lot easier).

I think I'll file this particular case under 'Unexplained'.

[Graham G3ZVT]

A market that used LW broadcasting, and used wavelength rather than frequency in 1978

['LIVEWIRE?']

Slightly irrelevant, perhaps, but British made Radios in 1978 were still calibrated in Metres rather than Khz

[turretslug]

Given that car radios very frequently used variable inductor tuning, I suppose it's possible that careful circuit design could have produced something that was able to tune all the way from 90 to 550m all in one go over both RF and LO circuits- this would have been headachey to the fringes of impossibility with gang variable capacitor. It's always possible that trickery such as tuneable LO and broadband RF was used to ease the frequency ratio conundrum. It still seems a puzzling choice of sub-MW coverage though- European market car radios would be more likely to go for separate 49m bandspread, Third World sets to span 60m and 90m, rather than the less-used 120m.

Perhaps it's more likely that the "radio" illustrated was simply artwork as opposed to actuality and the MW scale was penned by a technically uninformed person from sketchy rather than exacting memory. The opening titles of the Lenny Henry Show famously featured a digital artwork radio scale spanning 88-108 MHz FM- but 0-100kHz AM!

[Mike. Watterson]

I'd guess it's a mock up / mistake. Even with variable inductor tuning the 5:1 range is implausible, especially for the RF. There are ways to do the L.O.
There are a very few sets that have LW & MW on one band, but they have terrible RF tuning and it's by using a much higher IF than normal.

There are car radios, both valve and transistor with Shortwave. Also most UK/European sets for export outside Europe replaced LW with SW rather than adding it.

It is mostly likely an artistic mistake and perhaps was meant to be 550m to 190m, not 90m. The LW band looks fine.
550 400 300 230 190 150 90 should be:
550 500 450 350 300 250 190 ?

Perhaps it was badly scribbled on a cig packet and the case mockup had no tuning scale?

[Maarten]

Originally Posted by Radio Wrangler

I learned some years afterwards that it had been brought from South Africa, and may have been exported to there at a time when such trade was politically, um, insensitive.

Philips had their own factory there, so it was probably locally made and therefore unknown outside South Africa. Instead of the G for UK or X for Netherlands, it probably had a letter V in the model number, or if it was a post 1965 model it might have had the digits 29 in front of the model number instead of 13 or 22.

About the mock up: I agree it was probably meant to start at 190m. Otherwise, it looks just like a German made basic model (the largest Philips car radio factories were in Wetzlar Germany and Rambouillet France, very convenient for supplying the car industry in those countries).