Lissen/Ever Ready 5214

[Mike Watterson]

I have the loose holders.

Anyway mount hole centres in mm from my home made valve tester.
5 pin: 39
Mazda Octal, International Octal (both Bakelite): 39 and 40, not sure which is which.
12 pin: 46
P8, B5 (like B4 but centre pin) , B7, 6 pin (with 2 fat pins) : 48
10 pin (German?): 49
P4: 49 or 50

The base excluding peg pins of P8 is maybe 33 and cutout is perhaps 40mm. The holes I have for the two octal bases are about 33, and that is generous.

So it's likely then either the 1941 is a later added guess or you have a very rare early all octal unless the paxolin octal bases are the size of the old paxolin B7 and P4 with a 5th centre hole.

EDIT:
I think the Mazda Octal is larger circle of pins than IO, but the mount spacing is the same.

[Amie]

The chassis cutouts for the valve holders in mine are about 34mm. So its never had side contact valves.

I'm told that the later sets that are all octal built, all have cord drive tuning, the oscillator coil beneath the chassis like the shortwave equipped 'comfort', also visible screw heads on the front of the set.

Mine has the three cans above the chassis like yours, friction drive, and no visible screw heads.

The valves, although possibly not original, are all short American 1xxGT types.

The 8uF decoupling capacitor may have had a date on it, but I'm not sentimental about originality YT tossed it in the bin, there's nothing else to tag the date that I can see, just the pencil script on the inside of the back stating a persons name and a date, clearly, Tuesday 23[sup]rd[/sup] Sept. 1941.

Bit of a stretch to think the case and chassis are different.

Does make me wonder if the fault had been on the set from day one....

************************

I thought the only difference with MO is size of the locating centre peg.

Amie.

[Mike Watterson]

No, the MO is altogether larger.

So you must have one built just after the factories in London were Blitzed, which was in 1941. A very rare early all octal. Presumably the models with mixes of P8 and Octal were using up odd stocks of P8 valves. Most of those where Comfort sets.

Almost all the octal 1.4V battery valves during the war were US imports. UK production was on types for the war effort.

International Octal (Created by RCA)
A 17.45 mm (11⁄16 in) diameter circle around a 7.82 mm (5⁄16 in) diameter keyed post. The heater pins usually 2 and 7.

Mazda Octal
The heater pins are usually 1 & 8. The heater pins are 55.5 apart and the other pins 43.5 apart. Not sure what units. I can see on my valve tester the MO socket has obviously wider spaced pin 1 and 8, about 10mm. Diameter of circle about 20mm, the IO socket measured with same steel rule from above looks like 18 mm (actually 17.45). Many were initially the 4V 7 pin just with the new Mazda base.
It was short lived and battery sets that used them switched to regular Octal during the war.

   

[Mike Watterson]

I'm told that the later sets that are all octal built, all have cord drive tuning, the oscillator coil beneath the chassis like the shortwave equipped 'comfort', also visible screw heads on the front of the set.

Only much later ones had the visible screw heads and cord drive, the same as the Model A. Perhaps it only differs in having the 3 way wavechange with off rather than on/off on the volume control of the 5214 and comfort family of sets. There is no doubt that while the A is cost reduced cabinet compared to the 5124, the chassis is more securely mounted and the loop aerial makes more sense. Similar loop on the K and T.

If I run out of stories to write I could make up one schematic to rule them all with helpful hints. Except the G but including A and D.

I'd like an Octal C. Mine is a C/A or C/E, I forget, same relation to a C as the G is to D, a 250mA all B7G set. Punched out for octal.

[Mike Watterson]

Oh, and the battery plug on the 5214, used from 1939 to 1962 approximately, for 1.5 & 90V nominal combo balanced batteries?
It's the B4 valve connections. With LT were the heaters/filament would be and the +90V where the Anode would be, the pin spaced off.

   

Obviously the top cap is needed with the B4 either with indirectly heated triode or the battery SG (Tetrode) valve. Some early Pentodes added a screw terminal at the side. Then they added the middle pin for B5. Some 1928/1929 battery Pentodes come in both versions.

[Mike Watterson]

Mazda Octal
The heater pins are usually 1 & 8. The heater pins are 55.5 apart and the other pins 43.5 apart. Not sure what units. I can see on my valve tester the MO socket has obviously wider spaced pin 1 and 8, about 10mm.

It's degrees. From Wikipedia
18.5mm circle, 55.5° between pin 1 and 8, 43.5° between the other pins

[Kalee20]

Mazda Octal
The heater pins are usually 1 & 8. The heater pins are 55.5 apart and the other pins 43.5 apart. Not sure what units.

Units... Degrees.

if you add the seven remaining spacings 43.5 to the 55.5 between 1 and 8, you get 360  

I have a NOS P base valveholder, I'll measure this to double-check, what the minimum hole size would be. But it does look like Amie's radio is octal from Day 1.

Agree with Mike, rivets aren't that hard to fit, with suitable tooling... Though nuts and bolts are even easier in the service workshop, so I'd honestly expect a retrofit to use these, not rivets.

And yes, fault could have been there from Day 1, too. Maybe it was even despatched deliberately misaligned, to stop it oscillating?

[Kalee20]

Side contact, P8 valveholder would need AT LEAST 38mm diameter cutout, for the style valveholder shown.

I've never seen any other types for P-based valves (mind, I've not seen many anyway).
   
Mike - your post 25 about battery sizes, move from accumulators to dry batteries, etc is interesting!

For the record, I do have a post-war Pye 67a superhet, released 1946, it uses 2V Mazda octal valves, but probably one of the last designs to use the MO base. Which is a shame really, the large spigot did allow the exhaust tube to sit within the spigot, so the whole valve could be more squat, have shorter lead lengths, and work better at low-VHF.

My own Ever Ready ensemble is, a 5033 mains superhet (4V B4/B5 valves except tuning indicator which is a P; Ever Ready branded, and their own type numbers); a Model K (all-dry B7G superhet), and a Sky Monarch AM/FM (all-dry B7G superhet).

The Model K is indeed a good performer (it'll be performing after sending this post), agree with your earlier post about it being a good chassis Mike.

I'm interested in the 5214, when it's working fully on-song, and how it compares with the Model K - Mike, any comments here?

* Edit - I now see we both posted about the MO spacing units earlier, must've been within a few seconds of each other 

[Mike Watterson]

Without a known good set of valves it's hard to compare performance.
The K is much better than the Lissen version of the 5214 I have. But I think it has it's original 1939 valves.
The K is better than the C/E or C/A I have. I have three different case styles of K.

However all of these sets are very good on selectivity. Much better than transistor sets with two IF transistors and valve models with very small IFTs. The IFTs are superb Q. The air cored IFTs tuned with mica caps in some early sets maybe be slightly better than some dust iron core tuned IFTs in theory, but I don't know if true. They are probably better than the simple cheap "ceramic capacitor sized" monolithic ceramic IF filters as they have spurious responses. You'll note that professional radios use a pair of IFTs to better match the ceramic filters and give better out of band rejection.

Also running on battery reduces the mains interference. The loops are a better size, more signal and Q, than the flat coils in the lids of attache models, they outperform a decent ferrite rod, whereas the attache sets with a ferrite rod outperform similar ones with the flat coil. The worst are the "personal" sets of 1941 an later (USA) and in UK the UK from 1947, the aerial loops are too small and the IFTs are small and poorer. I've a Romac, but I can't get it working, it's unusual as it uses a loop aerial in the carrying strap. It also is lacking a proper dual tuned 1st IFT.

So generally all the Ever Ready dry battery valve superhets with full size loop aerials from 1939 (includes Sky Queen, Sky King, Jester, Sky Prince, Sky Lord, A, D, G, K, T and maybe the C, C/A C/E, N, N and N3) perform very well.
I've a some valve Philips battery sets that are better (World, Annette, Colette) and a better Pye set (the World model).

My Model A is seriously lacking in volume compared to the 1939 Lissen. I'm sure that's valves.

I've some good Vidors and a McMichael as well as a Roberts all in upright style with the large loop aerials. They also work well. Most are Octal.

[Mike Watterson]

Anyway:
I'd think it's had octal since new. Maybe one of the first made outside London, at the Canal Works rather than Block A at Wolverhampton.
It's likely had the faulty cap (labelled wrong) and wiring since new.
I'd leave the cap on the valve base as it is as it also connects to v1 via c22 and it's fine there on mine.