[radiorich]

Hello Arran,
Yes, I agree I have a few sets that are the same and I have done a couple right after each other too.

Sincerely Richard

[morzh]

Arran,

No, I understood what you meant; I also meant the RCA140/K80 when I answered.

The very first one I bough, it has the sliding rails made of some wood or plastic, I forgot. The original ones are missing.
And the bottom cover of the chassis is missing too. I will have to make one.

Yes, it is convenient to have a reference chassis to look at. I will start at one, and then will see.

[morzh]

[Video: https://www.youtube.com/watch?v=LkBwojJZUjo]


So, this here is the video of me playing the radio through the Holtzer-Cabot horn I bought.
Well, "E" is the clear winner of this competition, but then again, this is probably not the best horn and at some point, if i find AK's "M" or a classier horn with acceptable price (they were $350-750 from what I saw), I might get it then.


   
   

[Arran]

Mike;
One thing to look out for on horn speakers are weak magnets in the driver, there is a process for "recharging" them, but I have also heard of some people simply placing rare earth magnets in strategic spots on the old magnets to strengthen them.
Regards
Arran

[morzh]

Arran

Thanks, good idea to try. I have tons of REMs.

[Chas]

if i find AK's "M" or a classier horn with acceptable price (they were $350-750 from what I saw), I might get it then.

I haven't bought a horn in years. Did get clobbered at a country auction maybe 30 years ago for a Burns black celluloid petal horn. But most have been either free or cheap, less than 25$. May look at some variation of Magnavox, but mine all suffer from wither open transformers or open voice coils. I have an ACME drum cone and two cast-iron cones one of the Galleon and the other a Castle. Mica diaphragm balanced drivers for horns are rather good sounding, such as Thorola. Beware of pot-metal failure if buying online. Insist on seeing all of the driver and that the diaphragm clearance adjustment is free working.

Chas

[morzh]

I have no experience with horns. I pretty much use the battery (was carrying a 9V in a plastic sandwich bag around the Kutztown show, testing all horns).
Then again, online buy if on eBay, should a horn that was sold as working be DOA, it will be returned with full refund: eBay enforces it.

[MrFixr55]

Chas, that is great info. I did not know that anyone made mica diaphragm horn drivers; that definitely is an improvement. I have a set of mic diaphragm "cans but o not have a band to fit them.

Worked on an RCA Frankenhorn with an Amplion driver and a wooden lamp base that definitely suffered from pot metal disease. Replaced the "carrier" with 2 spring loaded 8-32 screws with thumb nuts to adjust.

The prices that Mike described are rather high, but they are high on eBay also. I would be happy to just have a complete horn with base, but the days of picking up one even non-working for $25 are long gone. If the driver doesn't work, I can bury a 2.5" speaker and transformer into it if I can't fix it. I have several radios from 1921 -1924 including an A-K 10C a Westinghouse RC and a FADA 160, so I do need a horn to display these with.

[MrFixr55]

Mike, I have a GE S-22A (GE version of the RCA R7A "Superette"). Different tube layout but similar construction method to your 140. The chassis mount insulators are rubber. They are rectangular and open on one side to slip over the "tangs" on edge of the chassis. The chassis is notched. There are 4. Mine is missing one. Other than that, I replaced some resistors and the electrolytics, and it plays rather well considering it has the biased triode "power" detector. Has a 10" electrodynamic speaker (similar to the Radiola 80) and 2 '47 output tubes in push pull. Came from Utah and was one of the cleanest radios I ever received via eBay. Has the nice copper Marshon caps. I didn't stuff them; I hid the new caps on the underside of the chassis.

One advantage of that painful bottom cover is how nice the wiring looks. Not faded at all on my set. All globe RCA tubes except one '24A that was gassy. New ST version under the tube shield. Way cool!!

[Arran]

I'm becoming more and more ambivalent towards the pricing of anything listed on Fleabay, especially many of the BIN prices, or $XXX or Best Offer. There is one guy on there, in Italy, who asks at least four times what the next highest listing does for rather common tubes, it's not surprising that he does sell very much, so I'm not sure of what he is basing these prices on, maybe conflating USD for Italian Lira? So it's no surprise that his most recent feedback is more then six months old. The ones that puzzle me are where they try flogging rectifier tubes, which are full wave to start with, in "matched pairs", I guess it makes as much sense as those $400+ power cords I saw a few years ago.
I figure if you really want to see what something can sell for on there, you make a search under "Completed Listings", but that is only really valid for Fleabay. In truth Fleabay has been largely bypassed by other selling platforms, much of what is listed now is AliExpress or Amazon type junk, new, but cheap import stuff, sometimes direct from the "Middle Kingdom". I would be reluctant to buy a speaker off of there, many of the jokers posting on there have no clue how to pack anything, the one I bought, the Dictogrand, is quite compact, it would fit in the same sixed box as an average 1930s five tube table radio.
Regards
Arran

[Eliot Ness]

The horn speakers just look "right" with a breadboard. But one thing to keep in mind is after the E series type of speakers were introduced, someone could have paired one with their breadboard.

[morzh]

John

It's fair statement. I think, E-speakers were introduced in time for people with breadboards to be able to use them to significantly improve the sound, so it still can be considered time-appropriate.

Are there any of the horn speakers that would sound at least comparable to the paper cone ones of "E" type (granted, "E" is still not what the paper cone speaker became in just a few years, which was almost a revolution in sound quality).

[Eliot Ness]

Are there any of the horn speakers that would sound at least comparable to the paper cone ones of "E" type

For tone quality probably not, but a good horn with a strong driver should have plenty enough volume for listening. Even a very cheap horn using a headphone driver had plenty of volume when I was messing with old three dialers. The key is a good strong driver. Play around with adding magnets to your new horn like Arron suggested.

[MrFixr55]

According to Radiomuseum and Harvard University's collection, the A-K model E speaker was introduced in 1926 and made till 1929. If one wants a cone type speaker that is period correct for an A-K 10A, B or C, the original Timmons Talker was available in 1924. There are 2 currently on eBuy. The RCA 100 speaker was available in 1925. I don't know when the A-K Model 10s stopped production. The Model 12 and the Big Box Model 20 were available in 1924.

[MrFixr55]

More on the Horn vs Cone speaker discourse. 

The A-K document "Instructions for Atwater Kent Open Mounted Style Receiving Sets" (i.e. Breadboards such as the Model 5, Model 9s, Model 10s Model 12, etc.), reproduced below, states on Page 2 under "Required Equipment", that "Any standard horn type or magnetic cone type speaker may be used".  The above instructions also recommend use of a 6V battery charger and "B" eliminator" if House Current" is available.

Atwater Kent Open Radio IFU Fr Museum of Yesterday.pdf Size: 1.92 MB  Downloads: 188

The problem is that these instructions were published in 1929, 5-6 years after introduction of the A-K breadboard radios.  From my limited research, A-K did not make a magnetic cone speaker until the Model E, made from 1926 to 1929.  Earlier magnetic cone speakers included the Timmons Talker (introduced 1924) and the RCA Model 100 (introduced 1925).

It is interesting that these instructions were published in 1929, 5-7 years after the introduction of the first Breadboards. (The Model 1 was introduced in 1922, The Model 5 and the original Model 10 Radiodyne were introduced in 1923, the Model 10 A, B and C and Model 12 were introduced in 1924.)  I don't know how long these sets were made but the Model 20 was introduced in 1924, the 20 C (Compact) was introduced in 1925, the Single Tuning Dial" Models 30 in 1935, the metal cased Model 35 in 1926, the first AC A-K set, the Model 36 was introduced in 1927.  The metal case Model 40, Model 44, etc. were introduced in 1928The much more sophisticated Model 55 was introduced in 1929.  In other words, This manual was published 4 generations after the breadboard sets.  The Model DE speaker was introduced in 1926, along with the Model 35 which had the '71A "power tube" audio output.

I don't know when A-K ceased manufacture or sale. (Did they have a backlog like RCA did on RA/DA, RC and other sets?)  The fact that they introduced a manual for these sets in 1929 (Or were there earlier versions of this document or merely the original instructions for each set?)  Indicates their support for these sets 5-7 years after their introduction.  Nowadays, try to get a manual from a product's website that was introduced 5 years ago and discontinued 2 years ago.