Perdio Park Lane - but it's not !!

[coopzone]

This radio came my way a while back now, it was only today a took a closer look. On the face of it it looks like a park lane model from the late 50's early sixties. But the PCB is not labeled PC-16. And it uses components what what i would say to be 1970's.

One photo shows two capacitors that look damaged, but i think they are deliberately trimmed as part of the tuning process - saves on a trimmer! (sorry photo not to good and can only see one capacitor)

Can anyone help ID this model. See attached.

Derek

[paulsherwin]

There appear to be some silicon transistors there.

[coopzone]

I thought that, some look silicon in the IF stages, but the output one not so sure?

[G6Tanuki]

Yes, those brown 'jellybean' epoxy-encapsulated transistors were introduced by Fairchild Semiconductor around 1960 along with their "uL" resistor-transistor-logic-range. Churned out by the million and sold for ten cents each, these transistors really were the foundation of the low-cost relatively-high-reliability consumer electronics industry.

The output transistors look to be like some of the 'plastic sheathed' PNP germanium types made by Ediswan in the late-50s/early-60s.

http://www.wylie.org.uk/technology/s...an/Ediswan.htm

The IFTs look like typical Far-East 1960s/early-70s 0nes. Is that a Mullard/Philips blue electrolytic I see standing on-end in the first photo?

[Paul Stenning]

It looks like a PCB made in the far east in a UK made cabinet. Probably to reduce costs while still still claiming it's made in the UK (or perhaps "assembled" in the UK as Roberts claimed on some of theirs).

The mix of silicon in the small signal stages and germanium in the output stage suggests late 60's - early 70's.

I have seen those "adjusted" capacitors before in sets from the far east of that sort of era. Sometimes there is paint over the nibbled area. As you say it saves on trimmers!

[coopzone]

Yes the capacitor is a Philips one.

Does anyone know of the circuit diagram for it? It has one printed on the back case but no values! just the component numbers.

Derek

[G6Tanuki]

Originally Posted by coopzone

Yes the capacitor is a Philips one.

Along with the under-chassis yellow capacitor in one of the other pics, this leads me to think that this radio has perhaps seen at least one instance of 'rework' in the last 60 years or so.

[Restoration73]

Full details in 1963-4 Radio & TV Servicing Book, page 200. Listed as "Londoner" the same
chassis is used in Park Lane, Super-7, and Piccadilly models. However this version
uses UK germanium devices, so yours could be later.

[paulsherwin]

I wonder if it's some sort of prototype.

[coopzone]

I have it listed, or at leat looks the same as the Park Lane. And as you say all the models listed use the pc-16 PCB with uk OC type pnp transistors. But not this one, so still looking for a circuit. More so the values used, as the circuit (on back of case) looks pretty close to the same as that used in the early models.

I was thinking not so much prototype but perhaps a Chinese copy 'rip off' version.

[greg_simons]

Looks genuine enough to me and I've never seen those 1/4 watt carbon comps used by far eastern makers, could be a prototype or later silicon version of an earlier model.

[coopzone]

This is the circuit from the back of the radio, as you can see, apart from q6 and a few other minor changes it's pretty much the same. Does it help anyone recognise the model/design?

Hope it's ok, if not please remove it.

Derek

[G6Tanuki]

Interesting that the circuit has two stages of IF-amplification; to my mind that puts its underlying design back to the early-60s and the days of OC44/OC45 when you needed 2 stages of IF to get adequate gain.

But equally, the IF-strip does not include neutralisation which would have been necessary with first-generation Germanium transistors. [the big thing about second-generation Ge transistors like the AF11x/OC17x series was their lower self-capacitance so they didn't need neutralisation in the IF-strip].

Fascinating!

[buggies]

I would say it has never seen the inside of a Perdio factory or lab.
The inspection label is wrong and (re the circuit diagram) I did not spot any "meters" mentioned in the text.

[coopzone]

Well spotted! I missed that one, I am even more of the opinion it's a copy - I wonder if it was perhaps one of the first ever done of a radio!

Derek

[davidw]

Having blown that diagram up a bit it looks like NPN transistors to my poor eyes but the manufacturers diagram says PNP OC series. The board also is labeled PC-7PL perhaps meaning Park lane?
I stand to be corrected however!

['LIVEWIRE?']

I wonder if the fact that, on the label, the use of the 'meters' spelling (instead of 'metres') is a clue to it's origin/i

[Reelman]

That label looks very similar to the ones found stuck to the back of 60s Hong Kong (Empire) pocket radios.
Peter

[G6Tanuki]

The label also says "Eveready" battery rather than Ever Ready; from what I remember, the former spelling was the US/world-market one and the latter spelling the UK one.

Perdio ceased trading in October 1965; I wonder if perhaps there was some 'old stock' somewhere down the production-lines which was cobbled together (with some other bought-in bits) to use it up? Or perhaps the incompleted sets were disposed via the likes of Practical Wireless etc. ?

[FIXITNOW]

I do remember some surplus stock being sold it electronic mags from the various dealers not marked as Perdio but looked as if they were