Can anyone identify this old Marconi radio please?

[Slash909uk]

Hi all, I have been emptying out my late father-in-law's sheds and found two military valve radios. One is an AR88D (which I am hoping to get working properly again with lots of help from the threads on here, thanks guys!), the other I cannot find anything like it so was hoping someone could help me identify it before it get's thrown in the scrap metal pile!

I have a picture of the front panel, marked 'Marconi receiver Type RS4' but a Google picture search turns up only old power supplies


I prized the case open at the top and inside are 4? 5? anode cap valves. It was too dirty to identify any markings unfortunately. I'd guess from the valve design it's 1930s? Couple of switches smashed off, tuning is seized, wiring rotted, not in a good way

I'm just curious to know what is is and if I should bother trying to save this one or not!

TIA
Stuart

[Cruisin Marine]

Well worth saving, being so old, it is real history. Marconi were the biz, always had a lot of respect for them.

[Cobaltblue]

Hi Stuart and welcome to the forum.

I have moved your picture into the thread as links get broken over time.

Hopefully someone recognises the set would it be possible to get a close up of the Brass plate?

Cheers

Mike T

[turretslug]

Hi and welcome.

Definitely worth restoring that set- there were plenty of wartime sets made and many survived post-war to displace those earlier sets that were made in much smaller numbers anyway, so those that survive are certainly significant and worthwhile. From the beginning of the 1930s to the end was a period when sub-30MHz radio technology markedly evolved and matured, so a set like this will provoke a good deal of interest here.

Good luck with it, Colin

[dave walsh]

Hello and please tell us, perhaps, what you know Stuart, re your own technical knowledge [you would seem to have some] and maybe what your Father in Law was up to with those sheds? Trust me, we often find out an amazing Wartime History from individuals, with a link to the Forum. Don't rush to throw things out without consultation. The info available on here is extraordinary and often the smallest item, down to components or screws, is invaluable to someone. I've benefitted from that myself

My own personal search involves the Marconi Station at Newhaven [Circa 1909] much earlier than what you have found but the 1930's were quite amazing and progressive in themselves. Good luck with the AR88, they were very much in demand a decade ago and there is no end of info here

Dave W

[GW3OQK Andrew]

Looks like a 5 band receiver, CW/phone. I can't read the left hand knob. Maybe for Marine use with a DF loop. Some more pictures would be interesting.
73, Andrew

[60 oldjohn]

Originally Posted by Slash909uk

I have a picture of the front panel, marked 'Marconi receiver Type RS4' but a Google picture search turns up only old power supplies :-
TIA
Stuart

RS4?

[Silicon]

Any chance of a close up photo of the brass identification plate and a photo of the internals?

The receiver may have been modified over the last 80 years.

[Gridiron]

Definitely worth saving, a very rare set now.
Louis Meulstee's "Wireless for the Warrior Compendium 2" has a picture and information on the Marconi RS5E which looks very similar in appearance and was used by the British army.

[Slash909uk]

Hi all - thanks so much for the feedback. I have been busy with other things so not visited here for a while..

I have finally managed to get the Marconi unit from the shed in Cornwall to my house, so we can take a proper look at it ( along with some other badly corroded valve HiFi! ) and it does look very much like the RS5E shown here: http://www.wftw.nl/rsets.html

I have no idea what it was doing in the back of the shed - my late father-in-law was a bit of a hoarder but perhaps these came from a relative who we know was into 'wireless' during the war and later thereafter.

Anyway, here are some more photo's; inside is mildewed and dusty/dirty but not much corrosion, so holding out hope the wound components are OK. Big plus, I found a wiring diagram in the case! Valve parts are: KTW21MET x 3, X.21, LP2, HD22MET, HL22MET and KT2. I guess that dates it to pre-early WW2, 1937 onward?

Some work has clearly been done already (output txfmr bolts are not straight and suspiciously shiny) and there is a mix of valve brands (Osram, Marconi, Cossor.) One of the coated valves appears to have decayed externally, and is not inserted in the socket fully. Hmm.

There is no PSU. It needs LT and HT supplies, perhaps there is/was a separate PSU somewhere?

Stu

PS: a bit about me - recently retired radio and IT engineer working in telecoms then digital TV, electronic hobbyist as a kid and spent my early years playing with TVs, radiograms, reel-to-reel tape units and whatnot. usually converting them guitar amps and effect units!

[Julesomega]

Ooh that's lovely, pity it's so corroded; a simple communications receiver with one RF stage. What is the frequency coverage?
It reminds me of a Marconi Marine receiver from the 50s, the Marconi Gannet which had a separate PSU chassis but mounted in the same cabinet with the receiver

[Gridiron]

Looks like the set was intended to be powered by an HT dry battery and a 2 volt accumulator for the valve filaments,
Mike.

[Silicon]

Please look after that schematic.

It may be the only one in existence.

I am sure that several members of the forum would be interested in a readable scan of that document.