EH Scott Radio Enthusiasts

The Fine Things are Always Hand Made

Can anyone help me with info on what is a single dial spider coils 10 tube version if the more common 9 tube AW 12 deluxe. It has no tuning meter and 5 pin sockets in tree RF/IF stages and came with  24A’s and one 35 which I assume are the original fit out, but the detector and AF driver stages have been modified with later tubes eg p/p 2A5’s where I believe there should have been p/p 27’s or 56’s, Early 1932 would be my guess. I have no power unit, but assume it is the 80 + p/p 45’s one if two dial thru ‘23.

I have seen pictures of this one with the extra tube but no info ( eg in Flick of the Switch). Info on correct tubes and especially a schematic would be greatly appreciated .

Views: 216

Reply to This

Replies to This Discussion

Bill - I have two examples of different chassis with the 10 tube lineup - but these are all pretty custom sets. Can you attach some images of your chassis, and I need to know which tubes are in which sockets. I've made a study of these chassis. Also, I hate to say it, but there is probably no chance on a schematic. I've had to draw my own diagrams based on known Scott designs from the given period. Photos of the top and underside of the chassis would help me greatly - we may be able to figure it out, with some effort. The modifications may make it difficult though. If you need help posting pics here, you can email them to me at kent3256@hotmail.com and I will attach them to this discussion. Thanks!!

Kent

Thanks Kent. I will organise some photos as soon as I can get hold  my wife’s camera - she’s away at present visiting grandchildren. I think, too, that once I know the tube lineup I can cobble to greet her something in the way of a schematic from the nearest early 9 tuber.

Underneath the chassis is a horrible mess of lots of mid-air connected mods. I can’t believe the two p/p 2A5’s would have existed originally cooking away under the chrome overs? My guess is that they were a pair of 56’s or even 27’s. My rather wild guess is that for some reason the power chassis was never imported to New Zealand, or maybe it blew up and replaced by a single 80 and power transformer to feed grafted- in 2A5’s, which also maybe were driven by the higher gm 56 we found there, perhaps in lieu of an earlier 27?? (Unfortunately it seems that the power supply and speaker were thrown out when my friend’s father died in the mid 60’)s.

The 2nd detector is a puzzle as someone had put in a 6 pin socket for a 2B7 it seems (one of those was found with the set). 

Unfortunately the original RF/IF section tube sockets are not named and I am not even sure that the 35 is original, but I assume that the 24A’s probably all are.

Do you more or less agree with me re 2A5’s and do you have any other thoughts in the meantime?

 

Much appreciated

Bill

PS. I am keen to help my friend, especially as I remember this set from my childhood and anyway have only ever seen one other Scott (AW25) many years later when I was collecting Atwater Kent’s and involved in broadcast engineering in Christchurch and Wellington before I retired 16 years ago back to Tasman. (I note with some affection and amusement that Scott named his cabinets after NZ places, including Napier where my sisters lives).

My guess is that the circuit will be close to a 2 dialer but with the rotating coils (??). My friend has found a letter to his father dated late 1931from a New Zealander who was about to return to New Zealand from the US in which bringing a Scott radio back was discussed. As I think I have previously said, my friend’s father knew Scott from the famous early 20’s Tasman DXing trip.

B.

Bill - FYI -Scott sets evolved during a model run - including the single dial 12 tube Scott Deluxe (Deluxe refers to single dial tuning) from Spring 1932 to mid 1934.

For awhile, I had a really early single dial Scott (spring 1932?) and it was very much a 2-Dial but with a single dial with the internal wheel holding all the coils. It used the 2-Dial version amp 80 and pair of 45's with big internal ceramic voltage divider, big 8 pin Jones plug, a 5 pin speaker socket for a single Scott labeled 11 inch Rolla speaker, and most of the 2-dial tubes except had 56's instead of 24A tubes. So the were 24A's and a 51.

A lot of Scott cabinets over the 1930's had New Zealand city names.

The 2A3 output tube was introduced about the same time as the 2A3. Contemporaries Scott AW-15 of 1934-5 used the 2A3 while McMurdo Silver used the 2A3 in the Masterpiece 3 of 1934.

Any evidence your receiver started as a battery set,  but then subsequently modified extensively to be an AC powered set?  

Scott was building  both a 2 volt and 6 volt chrome plated version in the earlier 1930's (Kent has an example of each) and so they would not have an separate amp but had output tube(s) on the receiver.

Bill - I very much doubt the 2A5 output tubes were used by Scott. I would expect your guess of the 27 or 56 to be closer, and the "final" amp would still be on the P/S chassis, probably a pair of 45s for that era. As Dave noted, I have an Allwave 6-volt farm battery set which has 10 tubes on the chassis. Being a battery set, it uses a totally different lineup. 

As Dave also noted, the AW12 Deluxe chassis evolved. I have a set in my collection which has 24s, 27s, and 35s. That was the first jump from the 2-dial set. They later went to newer tubes throughout the tuner. That six pin detector socket - the later 12 Deluxe sets used a Wunderlich detector, which is a 6-pin tube. Again, the wiring will tell us more about the tube used. I look forward to getting some pictures.

Lastly - another of the Allwave 6-volt sets I know of is over in Australia. Scott sold a good number of sets in Australia and NZ. And he did love the towns for cabinet names, but nothing ever named Dunedin, where he was born. 

Kent

Thanks for your messages Kent and David. I am now rather inclined to it having been a battery set especially as there was only limited AC power available in Motueka (main Tasman town) in 1923 and the owner, Mr McNabb was a garage owner so charging batteries would have had no problem recharging batteries.

No photos yet Kent but I will email you an underneath sketch of the radio which shows 5 or 6 sockers that I think are original - 5 pin and one 6 pin so I don't think it can have been either the 2 volt version or the 6 volt version shown in "AW battery sets". Not 2V because no 4 pin sockets remain and so many 5 pin ones look original, and not the six volt version because many of those tubes would have been reused in the conversion instead of going 2.5 volt.

Definitely no sign of a tuning meter and I think no Wunderlich ever because it's not late enough (?).

Maybe the lineup included something like 15's (later fitted with the 24A's) and a 19 single or 49 pair in p/p ??  A 19 would fit the original looking six pin socket that is in the right place.

Is this set too early for a vibrator pack HT supply? Logistically that would have made sense.

I enjoy this detective work, but photos in a few days Kent.

Best regards Bill B.

Scott%2013%20001.jpg

Bill -

I'm inclined to agree, this probably started life as a battery set, circa 1932, maybe 1933. Once electricity arrived, someone probably rebuilt the set as a powered set. It would have been possible for them to change sockets, so I doubt we can even trust what is currently there. The socket positions and layout looks exactly like a couple of the AW 6-volt sets that exist. They were very popular in areas without mains power. 

I am unaware of a Scott with a vibrator supply, but anything is possible. I've often wondered if Scott built a 32-volt DC set, common here in the US with the Delco farm generators running on 32v. One thing I've learned collecting Scott sets for almost 30 years is anything is possible. They were a custom set builder, and that's Custom with a capital C. 

Pictures will be a huge help to me. I've got my battery sets and others to compare to. I look forward to the continued discussion!

Kent

I don't know that my photos got through so I'll try again. There was another one showing the coil spider which has no web like later ones I have seen photos of.

Attachments:

OK, looks like only two got thru.  Two more photos then:

Is it now more identifiable?

Attachments:

Great! I will take some time to really study the bottom view, but I can say for certain this set began life as a battery set. The lack of a divider resistor is one indicator, but also, as you face the set there are no capacitors mounted on the chassis to the right of the tuner. With the AC sets, there are one or two filter caps there to smooth the DC from the supply, battery sets lack this. Also, the coil is the earliest version (pictured in the first promo pictures of the Deluxe), later coils did have more material between the coils, etc. I should have asked soon, what is the serial number on the chassis?

Kent

Thanks for that breakthrough Kent. I have to say thatI have become hooked on Scott’s AW’s! (Did I say that on old colleague in Wellington has given me a complete AW15 with a burned-out power transformer. I go to Wgtn on Thurs to see grandchildren and pick it up).

But, back to the case in hand:

The serial number is C 219.

I would love to know what the original tube line up was. I am not yet convinced that a pair of 2A5’s was the best choice for an on-chassis conversion power output stage. To keep them under the covers, it I’d say it wants to be something in strict Class B to keep the heat diss down? 45’s?

Bill

 

They may have run the finals in class A-B, which provides better sound and less distortion than straight B. I haven't looked at the schematic or studied the spec sheets of the original tubes, but I suspect that is how they would have run the finals. God, I haven't thought of that fact in nearly half a century, but we learned it in A school when I was in the Navy. Straight B was mostly used where low audio distortion was not so much a problem, like in transmitter finals for CW.

Bill Bryant said:

Thanks for that breakthrough Kent. I have to say thatI have become hooked on Scott’s AW’s! (Did I say that on old colleague in Wellington has given me a complete AW15 with a burned-out power transformer. I go to Wgtn on Thurs to see grandchildren and pick it up).

But, back to the case in hand:

The serial number is C 219.

I would love to know what the original tube line up was. I am not yet convinced that a pair of 2A5’s was the best choice for an on-chassis conversion power output stage. To keep them under the covers, it I’d say it wants to be something in strict Class B to keep the heat diss down? 45’s?

Bill

 

Yes, I see 45’s in AB have zero signal In of about 30MA  which is quite low. i don’t have figures for 2A5/42/6f6 so would have to get technical after 55 years! 

B
Michael Lawton said:

They may have run the finals in class A-B, which provides better sound and less distortion than straight B. I haven't looked at the schematic or studied the spec sheets of the original tubes, but I suspect that is how they would have run the finals. God, I haven't thought of that fact in nearly half a century, but we learned it in A school when I was in the Navy. Straight B was mostly used where low audio distortion was not so much a problem, like in transmitter finals for CW.

Bill Bryant said:

Thanks for that breakthrough Kent. I have to say thatI have become hooked on Scott’s AW’s! (Did I say that on old colleague in Wellington has given me a complete AW15 with a burned-out power transformer. I go to Wgtn on Thurs to see grandchildren and pick it up).

But, back to the case in hand:

The serial number is C 219.

I would love to know what the original tube line up was. I am not yet convinced that a pair of 2A5’s was the best choice for an on-chassis conversion power output stage. To keep them under the covers, it I’d say it wants to be something in strict Class B to keep the heat diss down? 45’s?

Bill

 

Reply to Discussion

RSS

© 2021   Created by Kent King.   Powered by

Badges  |  Report an Issue  |  Terms of Service