'Good Morning' Brad and Marc,
Thanks for the quick response. Yes, my set has a round dial (550 - 200) and it looks the same as the one in Brad's photo except that my dial does not have the Radiolette logo on it, never did. There is a hole burned through it where the pilot lamp is, and that is going to be a restoration problem unless someone has produced replicas.
Marc, you said that the 78 has the same spec. as a 6K7, does this imply that the 6D6 (shown in the Model 37 circuit) is not a substitute for a 78? If that is true, the components around my 78 might not be the same as those shown in the Model 37 circuit.
Regards, Peter.

G'day Peter,

It's best to continue discussions on a specific topic by using the 'Quick reply' feature underneath the last comment. Don't worry about it this time though.

The AWA logo only shows when the lamp is lit. The logo is on a second celluloid film located behind the dial scale.

The dial lamp burn is a flaw that is all too common with Empire States. I would reckon that 95% of surviving receivers have this problem. Because the R29 and later models had pretty much the same square dial in both plain and pearl dial scales, there are people who make replicas and these are usually obtained through vintage radio club channels. The R27 is a much rarer beast though so I am not sure about replica dial scales for this model.

If you know someone who was a scientific instrument maker/fitter they may be able to set up a duplicate scale easily enough but the hard bit is finding a suitable material to make the dial scale out of. Also, the second layer of the dial scale which has the AWA logo printed on it would also have to be remade or the sillouhette of the hole the lamp has burned through it would show through the new dial scale.

One other thing too - I am not really sure how important it is but I always keep parts that I replace for heritage value. By this I don't mean condensers, resistors and the like but things like dial scales, escutcheons and even the original speaker grille off the R27 I own and I keep the bits stored safely so they can be inspected at a later date. If ever there is a chance in the future that someone could repair the speaker grille then I wouldn't hesitate to reinstall it on my R27, ditching the soon-to-be laser cut grille I have plans on making.

Thanks Brad,
I am new to the world of Forums (Fora?) so I apologise for my mistake. I am very grateful for the feedback I am receiving. I keep stuff too, in fact I still have nearly everything I have ever bought - well, at least the useful bits.
Peter.

No worries about the new thread Peter. I could merge the two threads by hand but this takes lots of work and due to a bout of laziness on my part (I write and roll out all the forum features here) unfortunately the forum software hasn't got a 'move' function as yet. We are all new hands once so I try to be patient.

I just wish I was able to help more with the information. The odd thing is that I have about 120 radios yet not a single circuit diagram and because of this I now regret letting my HRSA membership lapse all those years ago. The vintage radio clubs are probably the best resource for things like that.

Some of the members of this website have done quite well sharing their own circuit diagrams. I am just wondering if anyone would know if an AORSM manual is still protected by copyright. I'm lead to believe they have lots of circuit diagrams in them.

Thanks Brad,
I'll follow up your suggestions re the circuit.
Peter.

78 has the same electrical specs as 6K7 (Philips) It does not have the same base. The same applies to every valve in it 6A7 is the same as 6A8. 6B7 the same as 6B8, 42 = 6F6 & 80 = 5Y3.

All of the later are eight pin and will not fit in the same hole. This info is for finding data for fault finding.

I am sending Brad a jpg file of Mantel 27 Console 47 which is possibly what you have.

From memory I got a large piece of "Elephant hide" (Phan paper) Insulating paper ...call it what you will..... punched holes in it & mounted the new caps on that, as it could be rolled up.

I have written warning notes to be heeded on the back of this sheet (your only getting the front.)

Viz:--

Do not remove the end plate, to which the bundle of capacitors is mounted, without first desoldering the resistor attached to the output valve (42) Do note where you got it from.

Be aware that the Tuning gang is "above ground". This means that no part of the dial light [insulated with heat resistant material], or anything else should touch this assembly.

The R301 Variant has also a dial burn. This is because the globes are too long. The bulb type are too big in diameter to fit in the R301 slot.

I removed the bulb from some blown one's & replaced it with the "Grain of Wheat" type that Jaycar have. These can be set low and will not get anywhere near the celluloid. Light output I think is lower but ....

Marc

Please click image for higher resolution.

Circuit diagram is uploaded.

Marc and Brad,
Thank you for the circuit, it confirms that mine is a Model 27. I am having a lovely time trying to retrieve whatever is left in my subconscious of my training as a RAAF Wireless Mechanic in WW2 .

I really appreciate your help, and my apologies for not replying sooner but I have had some problems.
Regards,
Peter.

No worries about the time Peter. That is the beauty of forums - everything lasts forever.

The speaker transformer is cactus. The identification printing is unreadable except for what looks like the word 'Rola', which doesn't surprise me. The circuit in an earlier post shows that the Model 27 should be a 'TG1' but there is no mention of input or output impedence. My memory suggests either 3000 or 5000 ohms, does anyone know what it should be?

Regards,
Peter.

Use specifications for 6F6.

Radiotron data says 7000 Ohms 250V Wo = 3.2 Watts

Radio data says HT 240V so I would go with that.

Data sheet for 42 & 6F6 can be downloaded from "Franks Electron tube pages"

Marc