Thanks Frank. That makes sense. I should have got my head straight before I posted.

You are right Tallar Carl. See my earlier post...off to sleep on it. I'll check against what Frank said

Its ok Kimberly lol these things are sent to test us and if it was all easy then it would be boring.

This does look like a whole bundle of confusion. 330 looks like it was produced after the war, 1946 & 1947 and it was never unusual for WD to scarper off with valves & they usually got subbed with Philips ones on the production line.

The line up I see is 6J8 / EK2G; 6U7; 6G8G; 6V6 Rectifier 5Y3 & 365 VAC secondary, so I would be thinking 600V filter caps.

The 730 I have has ECH35 as a pentagrid.

As far as I can see EL3 is not listed in the Philips Data book I have. It more likely and that would have a cathode resistor around half that of 6V6.The only set I see at a glance with it is 221 (BC Only) made 1940: 221 had 6F6: So they may have used old stock when they restarted making radios after the war.

My 1946 HMV model 456A has a EL3NG/ EL33 (Apparently EL33 superseded the EL3NG) These are as I found impossible to get in Australia, I found and bought two from England, one NOS and one good used and both cost me over $100 AUD. From what I've researched as Frank F has stated the bias resistor is 150 ohms but for a 6F6 it should be 500 ohms, or 3-400 ohms for a 6V6 and running it with either a 6F6 or 6V6 may run the risk of frying the mains transformer, which is why I splurged out for the correct valve and a spare. Interesting though I never knew a 6V6 was derived from the 6F6, which is apparently a 42 with more pins! Interesting. The EL3NG/ EL33 is the octal based version of the EL3N which is a Philips valve with the contacts around the side of the base. I've got one of those too with an adapter to octal I found on Ebay. I used a 6V6 to test my HMV was working after it's recap, but as with your Breville, it was a fraction of the volume as the EL33. These might be costly but apparently it's because audiophile nuts have driven the price up because they are an absolute belter of a valve!

I am assuming Jamie Lee (without me checking the valve specs) that running it with either a 6F6 or 6V6 may run the risk of frying the mains transformer, if the wrong bias resistor is used. I see the price of the 6V6s can be quite high. I paid a high price for some valves when fixing a friends, trendy new valve amp for her music.

Kimberly, the 6v6s are quite cheap , I have some Russian ones here if you want one $10 plus postage which is about $8 so you may as well have two. The EL33s $100 bucks Holy C*p I better look after the one I have in my little general!

The price of 6V6 should not be super high as they are still in production. http://www.tubedata.info/ is a place to go to find valve info, rather than speculate.

That funny Philips base is a "P" base.

EL33s are only 35 bucks new and 15 bucks second hand from the HRSA Valve bank.

Here is a little lesson on valve genealogy - in particular for the EL3 series:

The first in the series is a EL3, which was part of the Philips "Red Series" family. This was shortly followed by the EL3N, which had some electrical improvements & a dome shaped envelope. Both EL3 & EL3N have a European "P" or side contact base. The EL3NG is part of the Australian Philips "Gold Series", the "G" in the type designation indicating a octal base. There is no such valve as a EL3G. The EL33, A & B are the European "Red Series" octals, which are directly interchangeable with the Australian EL3NG.

As mentioned these EL3 series valves are hard to come by and can be expensive. There is a way around this however. An adaptor socket from a octal to 9 pin & use with a 6M5 or EL84/6BQ5. The 6M5/EL84's are not exactly electrically the same, but are similar enough to use without making any circuit changes. EL84's are cheap and plentiful & could get you out of trouble until a good reasonably priced EL3NG/EL33 turns up.

EL3NG was only marketed in Australia. It's an EL3 (Philips base) but has an octal base instead. Same spec as EL3 and same pinout as 6V6 or 6F6.

Note that there are two completely different bottles that are called EL3! Probably happened due to the fog of WW2. WE are looking at the low power version.

It was promoted as a way of eliminating the 1st audio amp and avoiding the complexity of a reflexed IF. Since your set only has 4 valves that's exactly what has happened. Which is why the volume is low, the 6F6 has even lower gain than the 6V6.

The 6F6 needs about 400 ohms in the cathode, vs. the EL3NG's 150.

It's a rare bottle, I tried to find one a few years back for an STC and failed. A 6V6 is a closer replacement, is readily available and will give you a little more gain than the 6F6.

Since EL3NGs are unobtainium, and that radio would still be fairly quiet with anything else, there is another possibility, inspired by the Kriesler 11-99 mantle radio.

This is assuming you want a working radio and aren't too fussed by absolute authenticity.

Use a 6GV8 (the TV vertical deflection brother of the 6GW8). They are cheap and easy to find. Wire it up in an octal base with a couple of passives so you have the triode as the 1st audio amp. Should be a plug-in substitute for the EL3NG. You get heaps more audio gain and a usable radio.

The EL3NG was never the solution its proponents claimed it to be. Neither was AWV's 6BV7, a later attempt at the same thing.

I have been doing plenty of research today. Most Breville 300/330s had a 6V6 as audio amp with not much else changed apart from a few resistors. That gives me plenty of confidence to go ahead converting it to a 6V6. Thanks for the other suggestions but it will be pretty close to authentic with a 6V6G as audio amp with nothing else except bias resistor changed.

The final line up will be 5Y3G rectifier (original), 6J8J Mixer (original), 6U3G IF (original), 6G8G RF and AGC (original), 6V6G Audio amp (changed but standard on many models) and a changed bias resistor. A pretty standard lineup for many versions of this radio according to what I can see.

Ian, my set has 5 valves. Not the fog of WWII but the fog of a very stressful Monday at work

Just to confuse you Kimberlyolse, why not use a 6V6GT even more readily available. Used or new.
JJ