Three-letter identifier

I know some of the old 3-letter identifiers were, e.g. MVA = M.C.A. London, MVB = Birdlip, MVU = Uxbridge, MVX = London, MTCA HQ but can anyone identify MVZ? See attached image.
Thanks, Colin

FWIW in 1915 that call MVZ was allocated to a ship called " Politician".

The picture looks to be 1950ish from the style of radio and dress....seems to be a CW(morse ) operation.... duplex if the board is correct . Band allocations have changed since the picture was taken but the 3khz channel spacing remains today.(3982 G/A, 3985 A/G)>
Will ask on one of my radio groups - someone will know.

Radio identified as Marconi CR100 - thus 1940s almost certainly.,
Most HF A/G comms were RT even long distance by 1950s so I'll revise my date to 1940s.

mbriscoe wrote:

And we all know what happened to the Politician!

But that was earlier than this.

Different ship ...the Whisky Galore ship wasn't named that till 1935.

Many thanks, yes I agree 1940's, CR100 CW operation. Looking forward to a possible ID, much obliged.
Regards Colin

The present day frequency block allocations did not come into effect until the 50s(ish)...the present day block around that freq being 3800 to 3950(part civil, part mil). I can't find anywhere which tells when present day freq blocks were agreed by the ITU. I know that when I first started listening to aircraft on HF back in the mid 50s, there was still some CW traffic . mostly military...the rest was all AM.

EDIT:Ploughing thru' the records of the 1948 ITU conference in Geneva indicates that Aero. freq allocations were rationalised in 1948 so looks likely that the picture may be dated pre 1950 ( ITU rationalising - and member states following that rationalisation are two different things...UK may have taken years to follow through.)
I will continue to read through the 1948 documents online as long as my dwindling supply of patience allows!

Delving into the ITU's 1948 conference details eventually confirmed that as of that date(1 Aug 48) the relevant frequency block for aeronautical comms became 3900 to 3950 kcs. Assuming a year or two for everyone to step in line the picture would seem to be 1945 to 1950....just guessing that wartime ops would likely have been in uniform of some kind).

So to summarise , I believe we are looking for an ATC centre that was using CW to communicate via a duplex system. I will add a guess that the operation was concerned with long distance over-water operations .....maybe akin to today's Shanwick operation.

Sad to say that many hours spent trawling the www have failed so far to reveal anything new apart from the suggestion on ABIX that it may be a comms station forwarding such as flight plans .
I know from listening in the 70s and later that by then this was done by RTTY (which I used to decode later using a ZX Spectrum)...this idea makes some sense except for the A/G and G/A freqs on the callsign board. .

The one place I can think of that might have the required info is in the ITU list of ground station callsigns.Thus used to be published annually in a couple of ginormeous volumes but I think for the past couple of decades it has been a computerised download. When I worked for the Gov in a radar establishment in the 60s we had this and also the ITU frequency list.(another massive tome)
Maybe someone here has a copy from the 40/50s .....anyone?

Just to resolve this item, I have finally identified 'MVZ' as Uxbridge ATCC.
Others within this sequence include,
MVQ Blackpool/Squires Gate
MVT Northolt
MVU Uxbridge (again!)

Thanks again to all those who contributed....