A true unique TV set: 27" Allocchio Bacchini

[Giulio Maiocco]

Hello everybody,I'm really proud to publish the end of restoration of a quite unique set in Italy: a 27" Allocchio Bacchini from 1954 with wired remote control!

As some of you may remember, quite a few years ago I asked help because of some weirdness of the horizontal output section, and the fact that the original flyback transformer was missing sure didn't help.

The circuit is inusual, at least here in Italy, it's a derivative of a much simpler and common 17 or 21 inch chassis, but with some modifications, in order to accomodate the much larger CRT, a 27RP4 with its different drive requirements. The flyback transformer is of the autotransformer family, but with series linearity coil connected at the damper tube cathodes and 2 taps of the primary itself, an arrangement found only in very few sets, mainly prototypes (for my Italian friends, as an example, the Geloso GTV1001 chassis 952 is one of these).

After a long time, almost 8 years from the purchase of this Allocchio Bacchini, I had the luck to find the correct flyback transformer, that, needless to say, once found it's specs on old catalogs, was only intended for 70° kinescopes up to 20", driven by a single 6AV5GT tube.

I tried to mount this FBT on the 27" chassis, bearing in mind it's original application, and it works perfectly, even with 2 6AV5GT tubes in parallel driving it full strength. As a result, the boosted voltage reached +590V (the original spec was 500V), the EHT is 16.7KV with normal brightness on the screen, the total cathode current for the 2 HOTs is 140mA, but I'm very happy because now the horizontal sync is perfectly stable and the flyback is not even lukewarm after more than 1 hour of operation.

During this resurrection, I had to change the tuner, someone in the past tampered with its adjustments rendering it useless. This fault caused somehow the "drop like a stone" of the horizontal frequency as the fine tuning was adjusted, the yoke made some very nerve-wrecking sounds.

Another strange thing was the backward connection of the video detector diode, connected that way, exactly as drawn on the schematic, negative image and no sync, I simply flipped around the damn diode and everything's A-OK.

I know I already posted some photos of it about 2 months ago on this thread http://www.videokarma.org/showthread.php?t=253838, but I wanted to do some more tweaks to the controls and re-install the rewound original vertical output transformer (6300 turns of #38 magnet wire really tests your patience). At least my friend Telecolor 3007 will see it, after I promised him long time ago some photos.

Best regards

Giulio Maiocco

[Sandy G]

Neat ! Me Likey !

[Captain Video]

Wow, I bet that is an extremely rare set. Congratulations to you to have found it and restored it.

Here in Brazil, Invictus also made a 27 inch set in 1956 - I was shocked to learn that they had the guts to produce such an expensive beast, I always thought ( and still believe ) that it was already amazing that they and other manufacturers were able to make the 17 and 21 inch sets in a country that had one of the lowest incomes per capita in the world in the 50's. The fact that they went beyond that and produced a 27 inch really amazes me.

A few years ago I visited a fellow collector and he had ( I believe he still have ) the 27 inch Invictus TV. Unfortunately, he lives in a modest house and has to store his 200 TV set collection in various parts of the house; the 27 inch set was, with it's doors closed, in his small kitchen, with the dining table and chairs in front of it, blocking the way. So he declined to show me the TV with the doors open. The thing was huge, and I would have loved to see the TV with the open doors. What a pity. That set is soo rare that most likely I will never encounter another one of that model again in my life. I hope at least I may stumble some day with some vintage magazine that has an advertisement of that TV; if that ever happens I will post a picture of the ad here in this forum.

[Telecolor 3007]

Didn't know that in the '50's there arleady existed 27" picture tubes (C.R.T.). I thought they where avaible only in the '60's. 27" = 68,58 c.m.s. That was big even for the '80's.
I like that this tv haves a power transformer. I do hate sets without a power transformer becuse you can get electocuted on chassie and in the case of tube sets, if one valve (electronic tubes) was broken, the rest wouldn't work + they where more sensitive to voltage and frquency variations.
What is the 4th function of the remote control. You put the picture with the remote control upside down.

[Electronic M]

Here in the US the Dumont brand designed and sold a 30" set back in 1951 that you can read about here. http://www.earlytelevision.org/dumont_ra119.html

[electroking]

Great set, congratulations for the project! Are the pictures displayed from analog
transmissions, or are you using a converter (or a VCR)? What is the status of the
digital TV transition in your country? Best regards.

[Giulio Maiocco]

Hello my all-around-the-world friends, thank you for the positive feedback I received about this restoration, so far it's the longest I have ever done in terms of time it required from start to finish!

Unca Sandy (may I call you this way?), I'm happy you like this big "toy", it's quite American in more than a way, of course, in the remote event you (or other VK-ers! ) come to Italy, you are more than welcome to come to my place and, if interested, see it in person.

Captain Video Well, at the time I bought it, the seller, an ex Allocchio Bacchini Engineer, told me only around 100 of these sets were produced. I have no motivations not to believe him, from a brochure I found, this beast cost in 1954, year of introduction of this model, 490000 italian lire, a princerly sum equivalent of the cost of 3 Fiat 500 cars, so a lot of money! He is still alive and over 90 years old, so, if I have the luck to meet him again, I'll ask some more questions.

I think Italy's economics was quite similar to the Brazilian one (and now indeed is not a bit better, it's really sinking at an alarming rate, but let's not disgress), so I can confirm that 17 and, in a lesser way because already too expensive, 21" TVs were largely the norm, while 24" and 27" were quite rare and mainly destined to rich people or public places, so a large audience could see the first TV shows (as an example, "Lascia o raddoppia" with Mike Buongiorno).

I can understand the fellow collector with such a beast in a small place, mine stands around 4 feets and weights around 209lbs, my same weight, so it's a bit problematic, to put it mildly, to move this thing around, especially when there is nobody to help you.

Telecolor 3007 Yes, 27 inch CRTs were indeed available in the '50ies, but were imported from the USA. It's really a big and somewhat heavy glass jug, I had the misfortune to break the original CRT in this Allocchio Bacchini, I assure you, it was a scary experience handling the replacement kinescope I would avoid repeating unless strictly necessary. 17"?? No problem, it's almost a kid's toy, but 27inch? No way, thank you

Yes, this set fortunately uses a HUGE power transformer and it's not too dangerous to work on the powered chassis, but the vast majority of the Tv sets you can find in Italy are of the hot chassis variety, these too are not really dangerous, providing you know what you are doing.

About the 4th control of the remote control, it varies the brightness of the image (Luminosità is the italian term for brightness), but the photo is really not upside down, simply the remote control is a bit problematic to put on a surface because of the cable, so I took the photo with the cable hanging outside of the workbench surface. BTW, the remote's shell is made out of inox steel, so indeed a nice touch.

Electronic M Although I know your message is meant as a reply to Telecolor 3007's, the 30inch Dumont is a really fascinating piece of equipment, add to it the "fun" of a 25Kv on the metal bell of the CRT and the risk of a dud kinescope and... WOW, I want one..badly OK, OK, just kidding (grin)

Electroking Where I'm located (north-west of Italy), the digital switchover happened in late 2010, let me tell you I'm not a teeny weeny bit impressed by this so called "improvement". There are still very few places free from this disease, but these too are succumbing to the digital switchover.
I'm using a DVD player in conjunction with a RF modulator to feed all the TV sets I have in my laboratory. I cannot use "over the air" reception there because I'm located in a garage with concrete walls, so reception is not so easy, it's already quite difficult with a proper antenna mounted on the roof of a condo, to tell you the truth. I only have 2 vintage TVs at home, these are fed from a "digital converter", again interposing a RF modulator between the TV antenna terminals (and a 75/300 ohm balun) and the outputs of the digital box.

Best regards

Giulio Maiocco

[Telecolor 3007]

You can adjust the bass on the set or only the tone?
Off-topic: Romanians are the only people in Easter-Europe to speak a Latin language. Of course, since there are many Slavs around us, we introuduced quyte a lot of Slavic words in Romanian. But we where also influced by other nations around us: Hungaryans, Germans, Turks (Slavs, Hungaryans, German, Turks also formes ethnic minorities in Romania; we have some Italians too).

[Sandy G]

I wonder if the 27" CRT was locally-produced, or did they buy 'em from America ? Why go to the trouble & expense to set up for something that they'd prolly NEVER sell many of, when RCA or Sylvaina or whomever woulda been HAPPY to sell them all they wanted... Not saying they COULDN'T produce a 27" CRT if they wanted to, just thinkin' out loud...

[W3XWT]

Giulio,

Absolutely awesome!

John

[Glenz75]

Wow! What a fantastic and unusual television, looks good. I have a 25 inch Philips b&w televison from the late 1960's and that is large, so a 27 inch cathode ray tube must be huge!
Cheers
Glen

[bgadow]

I never knew Daisy spoke Italian!

As rare as a 27" is in the US, it is impressive to see one from Italy or Brazil. Many thanks for sharing!

[Giulio Maiocco]

Hi, I'm back, ready to answer to your questions

Telecolor 3007 Did I already told you that Allocchio Bacchini used some mad-scientist piece of circuitery on their devices? The tone control is wired in the feedback loop and as it stands at the moment, it increases the treble frequencies until the audio section becomes an oscillator producing the sound of a stuck pig. I simply believe that later they revised this circuit to a more normal and effective one

UNCA, I'll reply later to your PM (, BTW, you always starts my days with a grin), the 27" and 24" CRTS were USA sourced, also 21" sometimes, the smaller one were indeed produced in Italy, but the quality left a lot to be desired. Only later in the games (mid/late sixties), some companies started to produce these big kinescopes locally, mainly as a replacements, but again the quality was just not there. My 27RP4 is Sylvania, BTW, and it tests very strong.

John I'm happy you like it, some people think I'm crazy, but I like it very much too!!

Glen 25 inch TV sets are already very big, is your set equipped with a 110 degrees deflection tube? If so, the good thing is that at least the tube is short, my tube is a 90° one, so the cabinet is over 2.5 feet deep! Is your Philips Tv series string or fed with a power transformer? Our Philips sets all used P series tubes and the chassis is live with our 230Vac.

Bgadow (Brian?), no, indeed Daisy does not speak Italian, at least directly, but I think this TV show is always funny, even after 30 years from it's introduction! I must thank you, all of you, for sharing the photos of your incredible sets, here in Italy we can only dream of these sets, if you find a glass-metal CRT it's a really rare occourrence, more so a roundie, even B&W

Cheers

Giulio Maiocco

[Sandy G]

Kinda figgered as much. No reason to "Reinvent the Wheel" if you didn't have to, outsourcing the oversize CRTs from America made sense in a lot of ways.