[turretslug]

Keep up the good work Allan, this has been an absorbing detective trail, as said.

Looking at your block diagram on Radiomuseum, this tuner was certainly an ambitious undertaking that tried hard not to leave any stones unturned. It would certainly have made an excellent broadcast monitor with aspirations of fidelity beyond most comms receivers. As Synchrodyne says, there is a definite stranding between these two classes of receiver- a few, such as GEC's approximately contemporaneous BRT400, managed or endeavoured to straddle the divide, I wonder how this large, heavy and quite complex set compared in price.

The two sets of gang capacitors and their gear-train are striking features- the gang capacitor must have been one of the more expensive single components of any set, apart from the mains transformer, and the tuning drive was presumably bespoke. That investment would have been a very brave step for what appears to have been a small start-up. Both the Marconi CR100 and RCA AR88 had geared tuning drives with a good reputation for feel and resolution- but these were mass-produced professional receivers with a hefty price tag from major companies that had been established for decades. As I said earlier, this design does give an impression of trying a bit too hard.

There's an element of split personality in the tuning scale presentation, too- whilst it goes as far as 30MHz, (as opposed to 26.5MHz to span 11m broadasting) with its implication of amateur radio listening and "communications" pretence, the calibration at this point is in 3MHz chunks with no apparent sign of a high-resolution logging scale that would be necessary, or at least very useful and pretty much an expected feature really.

I think that there will be quite a few of us watching with interest, both from the technical and historical aspects,

Colin