mcmichael: 463; Different valves, tubes?

Instead of DL35 a 1C5GT  Should these be listed equivalent?

Instead of DAC32 a 1H5GT Should these be listed equivalent?

V2 is DF33, which is correct.

V1 instead of DK32 appears to be a 1N5GT/G I find a 1N5GT which is a pentode. Wrong valve.

For some 1945 & 1946 UK sets we find

DK32 or 1A7G
DF33 or 1N5G
DAC32 or 1H5G
DL35 or 1C5G

At least one capacitor in the radio is April 1946.

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The P8A/Edge connect seems to have been adopted by Philips (and thus Mullard, then Ever Ready who then were re-branding Mullard valves). So for "All Dry" battery radios (USA Sylvania Octal 1938) we see only from 1939 DK1 DF1 DAC1 DL2 but from late 1941 1A7G 1N5G 1H5G 1C5G, then in 1946:
DK32 replaces 1A7G
DF33 replaces 1N5G
DAC32 replaces 1H5G
DL35 replaces 1C5G

All directly replaceable Octals. Brimar of course continue to use the USA designations. Brimar was owned from "birth" by STC which was owned by the American ITT (so no surprise) who also owned International Marine, Kolster Brandes and Schaub (later Schaub-Lorenz).

This is seen on the Ever Ready 5214, which is also the Lissen 8514 / 8515 to finally the Model A

Early 5214 used side contact and gradually change to Octal types.

The edge (P8) and Octal valves/tubes are not base compatible but different production times and electrically similar. This occurs on many UK battery models between 1940 and 1945. Even in 1945 / 1946 the Edge connect types are unavailable and Mullard issues instructions on how to change the sockets from P8 Edge type to International octal and the list of Octal replacements. These changes are seen on Ever Ready, McMichael, Pye (See Baby Q Senior and New Baby Q) and others in the UK.

The UK BVA (British Valve Association), a condoned UK cartel, opposed imports so much that Philips quietly bought Mullard in 1928 and no-one except the "Tax Man" really noticed till 1939. Even UK types identical to US types would have a different part number (See Marconi valves/tubes!). Probably no-one knows how many "Mullard BVA" valves in the 1930s were really made by Philips on the Continent!

Mullard eventually had more than 50% of the market and created the Mullard Amerty Brand for American imports. Actually many of the Mullard Supplied P8A "Ever Ready" branded valves have "BVA" printed on the bulb but "Made in USA" on the base! For whatever reason (cessation of real Dutch source, Bombing of London, diversion of Production to Military etc) by the end of 1941 US Octal Imports or Allegedly UK Brimar Octal US part number valves/tubes are replacing P8A (edge type) in Radios. This was easy as the Octal sockets would fit the chassis punched for P8A sockets and not only  the base wiring is similar but the electrical characteristics are similar or identical. Who made the "Made in USA" P8A tubes anyway? Sylvania or RCA and perhaps some are the octal tubes with a P8A base?

Then we have virtually identical models (Vidor, Ever Ready, McMichael, Bush, Pye etc) in the 1946/1947 period with Octal then Miniature B7G even on the same chassis and "Personal" models (Romac 1946, Then in 1947 Vidor, Ever Ready, Marconi, Champion etc) seemingly delayed in the UK (USA 1940 personal Radio) suggesting post war shortages. Even the Wartime Civilian Radio was very much delayed to latter half of 1944 and most purchasers had one less than a year when the war ended and LW radio re-commenced, which wasn't available on most of the "Civilian" Radios (mains-octal, battery (US 7 & 6 pin 2V) and rare two band-octal, but no LW station in UK during WWII).

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Interesting that the pin allocation is identical for
DK1 and 1A7G
DF1 and 1N5G
DAC1 and 1H5G
DL2 and 1C5G

That looks as if american glass envelopes were put into side contact bases.
If the sockets were changed due to shortage of side contact valves, the chassis wiring remained identical, pin by pin...for use of US tubes.

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Yes, Ever Ready DK1 etc  with "Made in USA" on the P8A base re-enforces this. I suspect Philips/Mullard was using US imports for the P8A tubes and these were the same as for the Octal base. But how can we know for sure, or if it was Sylvania (who developed these in 1938), RCA, or was there a US tube maker owned by ITT (who I think owned Brimar UK then via STC, whoever else at later times owned Brimar. Brimar closed in UK only 2012 I think). Have we a date also for "Mullard Amerty" the Mullard brand for "official" US imports to UK? Mentioned in "Trader 534" 30th August 1941.

Other UK first "All Dry" battery valve radio.

UK Philco BP4 unsurprisingly uses Loctal in 1939

Mazda for their "All Dry" Battery valves used the Mazda Octal base in 1939/1940, but by 1942/1943 these too were being swapped in production Radio sets for US Octal (International Octal).

Decca MLD/3 with Mazda Octal and IO (USA designation)

More curiously Fergusonic 906 with P8A (edge connect) or (later?) Mazda Octal. That was a bad switch!  I will not be surprised if there is a Factory Production version of it with IO tubes (USA designation RCA/Sylvania/Brimar or Mullard/Philips European designation if still produced in 1946).

When did the 1940s Y8A or other Continental 1.4V (Telefunken?) tubes change to Octal/Rimlock B8A/B7G etc? There is an interesting range of German 1.4V tubes obviously current optimised so parallel only (The advantage of Sylvania's 1938 scheme and RCA's miniature 1940 versions is of course the identical 50mA series current on all parts).

DCH11 1.2V @ 75mA!  (But a Triode Hexode rather than Pentagrid, The later 1V6 is clever though)

DAF11 50mA

DC11 20mA  (nice triode for a phase splitter in 1940?)

DDD11 100mA (Not bad for Push Pull)

I suspect the idea was to replace the 2V or 4V Lead Acid Accumulator with a NiCd (DEAC) rather than dry cells. In the UK after 1945 the two dominant makes are Vidor and Ever Ready for Battey Radios who wish to sell Batteries, so no rechargable LT except on a few 2V sets (new models till 1950!) whereas in Germany and the Continent the Minature B7G tubes (till 1959) often had NiCd (DEAC) which no doubt started in 1940. with the tubes above.

Some 1940 sets using these interesting Telefunken tubes

Are there other pre 1945 Telefunken or other type All Dry (1.2V to 1.4V) non-USA tubes? Basically for "All Dry" Battery Radios the  early 50mA B7G/Minature, Mazda Octal, Loctal, Octal and P8A/Edge type in UK up to 1948 seem to be all USA derived (Sylvania/RCA). Presumably the Rimlock tube is rare in USA but compared with B7G/Minature saw little UK use in Battery sets. The DK40 is used instead of 1R5/DK91 till the DK92 appears but only for higher performance Shortwave in UK sets. such as Pye PE55MBQ (for export!) which otherwise uses B7G/Miniature types, no  UK models found with DL41.

 

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There is also the DF11 (used in 60 known models) and the DL11 (used in 40 known models)

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To allow series heating Telefunken decided to develop new battery valves for a unified filament current of 50 mA.

While the DAF11 and the DL11 alredy worked on 50 mA, the new DCH15 should replace the 75 mA DCH11, and the new DF15 should replace the 25 mA DF11.

See also the respective German Forum thread.

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I may have posted this before, but can't find it:

Used in Proximity fuses, probably a "grid dip" type oscillator and frequency shift due to ground approaching triggering a Thyratron to fire the bomb. Otherwise the bomb buries too deep in the ground.

Certainly by 1942 replacement valves for repair or new ones for Domestic Radio Production appear to have been unobtainable until US Octal imports for Domestic radio started.

 

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