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463

463; McMichael Ltd., (ID = 212931) Radio
 
463; McMichael Ltd., (ID = 533799) Radio
 
463; McMichael Ltd., (ID = 533801) Radio
 
463; McMichael Ltd., (ID = 1489054) Radio
463; McMichael Ltd., (ID = 1488912) Radio 463; McMichael Ltd., (ID = 209580) Radio
463; McMichael Ltd., (ID = 209583) Radio 463; McMichael Ltd., (ID = 209584) Radio
463; McMichael Ltd., (ID = 209585) Radio 463; McMichael Ltd., (ID = 1488910) Radio
463; McMichael Ltd., (ID = 1488911) Radio 463; McMichael Ltd., (ID = 1488913) Radio
463; McMichael Ltd., (ID = 1488914) Radio 463; McMichael Ltd., (ID = 1488915) Radio
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463; McMichael Ltd., (ID = 1488912) Radio
McMichael Ltd.,: 463 [Radio] ID = 1488912 933x865
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For model 463, McMichael Ltd., Slough:
Handle is detachable. Red MW scale very badly faded.
 
Country:  Great Britain (UK)
Manufacturer / Brand:  McMichael Ltd., Slough
alternative name
 
McMichael, Leslie
Year: 1946 Category: Broadcast Receiver - or past WW2 Tuner
Valves / Tubes 4: DK32 DF33 DAC32 DL35
Main principle Super-Heterodyne (Super in general); ZF/IF 465 kHz; 2 AF stage(s)
Tuned circuits 6 AM circuit(s)
Wave bands Broadcast (MW) and Long Wave.
Details
Power type and voltage Dry Batteries / 1.5 & 90 Volt
Loudspeaker Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) / Ø 7 inch = 17.8 cm
Power out
from Radiomuseum.org Model: 463 - McMichael Ltd., Slough
Material Wooden case
Shape Portable set > 8 inch (also usable without mains)
Dimensions (WHD) 11 x 11.5 x 6 inch / 279 x 292 x 152 mm
Notes

Brown/yellow crackle finish.

Batteries: Batrymax B117 90V HT and All-Dry 32 1.5V LT, about 150 hours.

Dual loop/frame aerials with adjustable loading coils to tune LF end of band.

Early production may have RCA/Sylvania/Brimar designations equivalent tubes. 

Price includes 1946 Purchase tax of £2.79 approx

 

Price in first year of sale 15.79 GBP
Collectors' prices  
Source of data Radio! Radio!
Mentioned in Radio And Television Servicing books (R&TVS) (1951 Vol 1 page 234)
Literature/Schematics (1) Trader Service Sheet (suppl. of Wireless & El. Trader, etc.) (803 February 1947)

Model page created by Konrad Birkner † 12.08.2014. See "Data change" for further contributors.



All listed radios etc. from McMichael Ltd., Slough
Here you find 175 models, 101 with images and 118 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.



 


Forum contributions about this model
McMichael Ltd.,: 463
Threads: 2 | Posts: 8
Hits: 944     Replies: 0
mcmichael: 463: Restoration
Michael Watterson
02.Sep.13
  1

This is one of the "transition" post war 1940s models like a 1939 model but with Octal tubes, often US types or Mullard Equivalents. The next year sees the 483 is almost identical chassis in a similar case but with B7G miniature valves. The 1939 All World 399 is possibly the previous battery model, though a table model rather than "portable", unless McMichael made some of the Civilian Battery Radios. Prior to 1939 most McMichael "portables" are of the large 2V suitcase type.

 

Initial issues

  • Four valves but a 1N5GT  fitted where DK32 - 1A7G Pentagrid/Heptode should be. A very new looking DF32 is in the 1N5G location. The remaining two valves are correct (Brimar and RCA make US numbers.
  • Lots of old woodworm flight holes, none looks fresh.
  • Red MW scale faded to unreadable.
  • LW legend flaked off "flag" on wavechange.
  • Scale Bezel loose.
  • LT ("A") Battery plug missing.

 

Dismantling

The metal bezel of wave change switch needed to be removed. Both knob grub screws are siezed but I manage to lever / twist / wiggle them off. Two brass hex around the shafts are not nuts, but partially rotate two metal arms supposed to lock the bezel in place. The entire chassis, loop aerial frame and speaker on baffle board lifts out.

 

Woodworm

Blow torch parts of inside away from cloth and soaking all woodwork with killer/preservative. Later inject all old flight holes with Rentokill. Later still soak again with the Ronseal fluid.

 

Missing DK32/1A7G and Valves

I Wired a B7G on an Octal plug to suit DK92 (or DK96). All the pins except g4 for Top Cap, g3 and g2 (cross over) solder direct to the Octal plug which is handy. I made a little "coffee tin" top cap with spreading base to sit on top of B7G valve.

DK92 on 1A7G plug

DK92 mounted on Octal plug

Only two wires had to "swap", one direct under socket and one at outside. The other four B7G pins and centre earth pin solder to the Octal plug pins directly.

I tested the 1N5GT and DF33 and they are both very good. Mysterious. So put the 1N5GT in for IF.

 

Leaky Capacitors

I checked 10nF waxy from DAC32/1H5GT anode to DL35/1C5GT grid and massive leakage. Replaced with 10nF poly foil. This is the most critical part in terms of damage on any radio as output valve, audio transformer and on a mains set even main rectifier and Mains transformer can all be damaged.

It "works" with B7G DK92 in the DK32 / 1A7GT socket... sort of. At 44V from bench PSU. Something was taking 110mA!

I suspected the main electrolytic (April 1946) screwed to case, so removed + and connected PSU direct. I set to 32V then adjusted current limit under 50mA (under 10mA is probably better). I'll leave it an hour and see has it gone down. Several hours later it's still at current limit and a slight bubbling at negative terminal. I replace it with a modern part glued into metal tube the same size made of coffee tin so it fits on baffle. The clamp is on one of the speaker mounts.

 

More Faults

It doesn't actually tune though. Proves to be a loose grub screw on the tuning drum. Now getting R4 (from UK) (weak) and RTE 1 very loud. So valves are good and DK92 works.

Probably need to replace some non-critical waxies on screen grids for decent RF gain. Replaced 3 other HT 50nF Waxies, very very high leakage, g2 decoupling on V1, HT decoupling and V1 screen decoupling. No V3 screen grid as it's a Triode, unlike later models.

The alignment was not far out on LW, but MW almost dead and way out.

Actually neither the MW or LW LO coil could be tuned.

So I undid the clip and found both cores (MW LO and LW LO) had broken off the brass screws.The IF alignment seemed poor too.

Of course the cores had cracked of the adjusters on these too.

I glued them on with superglue. I used the super shiny non-stick plastic peel off layer on double sided foam tape as a spacer to align in coil hole and pressed sticks from rear.

 

 

The set is now aligned.

So I found a tested "NOS" 1A7G cheap with cheap postage in USA. Cheaper than 1A7G or DK32 in Europe even accounting for cheaper UK or Spanish or German Postage.

 

The Scale

Approximate appearance and attempt at enhancement

 

However based on what logically the wavelengths should be and stations of the late 1940s I drew this one:

 

But then I found the 483 Model and processed the photo of its scale

Scale on the 483 in the Museum

 

Final version (not full size)

 

I also reprinted on cream card the "flag" as MW was nearly gone and LW completely gone. It was not far enough on the shaft so rubbing against the front panel.

1/4 resolution. Full size can be uploaded.

All printouts had clear background and printed on cream stock.

 

Batteries

I made replacement LT plugs from cut up coffee tin. I had already made replica 90V and 1.5V packs (L5155 using 60 x Alkaline AA cells in holders and 4 x "F cells" from a 996 soldered in parallel in an AD4) for my Vidor Vanguard. I'll probably make a B117 livery pack.

 

Finally

After 10 days the 1A7G came and the performance was no different. I will use PVA to glue cut cocktail sticks into the wormholes, cut flush when dry and get my daughter to "touch up" the spots with acrylic paint.

The set performs and operates really well on LW & MW.

 

 
Hits: 2003     Replies: 6
mcmichael: 463; Different valves, tubes?
Michael Watterson
17.Jul.13
  1

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.

Michael Watterson
21.Aug.13
  2

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.

1939 -1941: All dry Battery Portable 5214 early See
Intermediate and Late too.
Made in Lissen, London

P8A Edge types

1940 -1945: Forces Entertainment Radio

Mix of P8A and US Octal

1945 (post WWII) "A" All dry portable
Ever Ready, Wolverhampton.

Mix of US and Europe designations Octal

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).

Konrad Birkner † 12.08.2014
22.Aug.13
  3

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.

Michael Watterson
22.Aug.13
  4

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


A czeija Hekaphon 41B St-30552
A hornyphon K46B
A ingelen Batterie 41 (41B)
A minerva 415B
A radione 541B
A zerdik 63B
D aeg 450B
D blaupunkt 6B69/40
D lorenz BL41
D lorenz 15B
D mende 250B
D telefunken 54BK
N radionette NRK Batterisuper

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.

 

Konrad Birkner † 12.08.2014
23.Aug.13
  5

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

Konrad Birkner † 12.08.2014
24.Aug.13
  6

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.

Michael Watterson
16.Dec.13
  7

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.

 

 
McMichael Ltd.,: 463
End of forum contributions about this model

  
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