The AM Forum
March 28, 2024, 11:55:47 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: very old tube type 12A data wanted.  (Read 4905 times)
0 Members and 1 Guest are viewing this topic.
Opcom
Patrick J. / KD5OEI
Contributing
Member
*
Offline Offline

Posts: 8308



WWW
« on: February 03, 2019, 12:04:20 PM »

Does anyone have the full data sheet for the type 12A tube? If it is a version of the 12, It has a 1.1V filament and is identical to the 11, except the base. It is not the same as the 112A, which has a 5V filament.

I find the 12 only in the chart section of the RC10 and RC11 manuals. Did not find the 12A. It's not in the JEDEC documents, except for a revision of interelectrode capacitance and nothing else.

Found the 12A, 112A listed on the same line in the sylvania manual under obsolete types. That one is a 5V tube. Shows it running on 90-135V, which seems a stretch for a 32V radio set.


I'm trying to get my grandfather's old Crescentdyne 32 Volt AM radio working.
Crescentdyne Radio Manufacturing Co. Minneapolis, Minnesota.
Logged

Radio Candelstein - Flagship Station of the NRK Radio Network.
PA0NVD
Member

Offline Offline

Posts: 615


Nico and Chappie (Chappie is the dog...)


« Reply #1 on: February 03, 2019, 12:12:16 PM »

here  https://www.radiomuseum.org/tubes/tube_12a.html  are data of the 12A. But they say it has a 5 V filament.
the 12  https://www.radiomuseum.org/tubes/tube_12.html  has a 1 Volt filament
Logged
Tom WA3KLR
Contributing
Member
*
Offline Offline

Posts: 2120



« Reply #2 on: February 03, 2019, 12:28:50 PM »

Attached is a pdf of a page from my 1943 Sylvania tube manual.  It is 5 volts filament.

Ludwell Sibley's 'Tube Lore' states it is also known as the UX-112A.  On a later page under the UX-112A, "power triode similar to the 71A developed from Westinghouse prototype WL-112; fil 5.0 V @ 250 ma., u 8.5, gm 1.8 mS.

* sylvania1943 12A.pdf (786.65 KB - downloaded 196 times.)
Logged

73 de Tom WA3KLR  AMI # 77   Amplitude Modulation - a force Now and for the Future!
Opcom
Patrick J. / KD5OEI
Contributing
Member
*
Offline Offline

Posts: 8308



WWW
« Reply #3 on: February 03, 2019, 12:39:18 PM »

The Sylvania data there looks like it. The radio has a 8-10" speaker, but maybe there are two in push pull. 32 Volts? maybe zero bias. Well, on to the investigation. Have not found the schematic for the radio yet. A lot of this old farm stuff information has been lost. Granddad had a farm, and a windmill for pumping water. Not sure how he got the 32V batteries charged, might have been a generator that was long gone.
Logged

Radio Candelstein - Flagship Station of the NRK Radio Network.
PA0NVD
Member

Offline Offline

Posts: 615


Nico and Chappie (Chappie is the dog...)


« Reply #4 on: February 03, 2019, 01:30:24 PM »

The HV batteries were normally dry batteries and no rechargeable. The filament of 1 V tubes as well. Filaments with larger voltages were  normally lead acid batteries and the voltage was adjustable in the radio with a variable resistor.
Any idea of the year of manufacturing?
Logged
KB2WIG
Contributing
Member
*
Offline Offline

Posts: 4484



« Reply #5 on: February 03, 2019, 02:11:23 PM »



My father would hitch up the wagon and go to town with the batts.  The garage/ auto dealership/ farm supply would charge the batts.

KLC
Logged

What? Me worry?
W7TFO
WTF-OVER in 7 land Dennis
Contributing
Member
*
Offline Offline

Posts: 2521


IN A TRIODE NO ONE CAN HEAR YOUR SCREEN


WWW
« Reply #6 on: February 03, 2019, 11:17:16 PM »

Universally 32-Volt farm sets were operated off the bank of lead-acid cells, supplying lighting as well.  The battery was kept up by a engine-driven DC generator or more often, a Wincharger:

https://www.youtube.com/watch?v=FpeYLPcUBWA

Most farm radios developed B+ via vibrators, others employed dynamotors.

The 12 and WD-12 tubes were very early triodes, found in many RCA and Westinghouse receivers.  Not the same animal as the UX-112A, but similar to the UV-199.  https://www.radiomuseum.org/tubes/tube_12.html

A successful sub is a type 30.

73DG
Logged

Just pacing the Farady cage...
Opcom
Patrick J. / KD5OEI
Contributing
Member
*
Offline Offline

Posts: 8308



WWW
« Reply #7 on: February 03, 2019, 11:43:52 PM »

No specific data and no model number on the set. I am almost sure it says "cresentdyne" but it may be "cresentyne", the info is very faded. It's a single tuner TRF set.

I did a bunch of digging on the web about the set itself today looking for pictures and tech data. The brand of set was mentioned in a 1933 article on sales+service business opportunities as a candidate for replacement, so it may have been 'obsolete' then even with many happy users.

A similar looking chassis was dated 1927. Crescent Radio Manufacturing Co. was apparently a small company, and in those old days, things like schematics and specifications didn't always make it from the many small companies to the industry publishers. I guess mid 1920s.

It is similar to the "M" series from Crescent. All the Crescent radios found so far are listed as 67.5V B+ and 6V "A" battery. That's different than 36V, which may be in error, might have been 32VDC in reality as more common farm voltage? The power requirement was verbally related to me and the set had not been used for 70+ years. No one ever mentioned A and B batteries either, so it was probably all forgotten.

Probably have to remove the chassis and draw the schematic myself. Not used to TRF designs or anything this old but if I can tell the ancient resistors from inductors and /or capacitors and rely on the tube pin-outs then it should not be hard. To me it seems weird that all the tubes are the same, but the 12A is listed as a detector and as an amplifier.

I can try to post a picture, the set got moved behind a pile of stuff, man what a mess I have.

Logged

Radio Candelstein - Flagship Station of the NRK Radio Network.
Joe Connor
Member

Offline Offline

Posts: 47


« Reply #8 on: February 04, 2019, 03:56:23 PM »

This sure sounds like one of the early battery sets ca. 1925-1928, not a 32V farm radio. I've seen '12A tubes used in some of these early sets, so given the 1927 date that you have, the chances are that it is a '12A tube. The A and B voltages you found sound about right for an early battery set.

Your best bet is to inquire over at the Antique Radio Forum. There are some real experts over there on those early sets. I'll bet someone there will be able to identify your set and maybe even supply a schematic.
http://www.antiqueradios.com/forums/index.php

Those were the Wild West days for the radio industry, with lots of small manufacturers that are forgotten today. A lot got wiped out when the more complicated superhets entered the picture and when the Depression killed a lot of small businesses.
Logged
Opcom
Patrick J. / KD5OEI
Contributing
Member
*
Offline Offline

Posts: 8308



WWW
« Reply #9 on: August 27, 2021, 09:57:29 PM »

The HV batteries were normally dry batteries and no rechargeable. The filament of 1 V tubes as well. Filaments with larger voltages were  normally lead acid batteries and the voltage was adjustable in the radio with a variable resistor.
Any idea of the year of manufacturing?

Replying to this very old, specific topic.

The date of manufacture is well before 1933. In 'Radio Retailing Magazine', January 1933, there is an exhortation to radio salesmen to find these "old timers, perhaps still operating in somebody's sitting room", and sell in a modern replacement.

So, on that old rig, I have drawn a schematic from examination.

It's confirmed from analyzing the schematic to be operated from a single 32VDC source, so that would be the old "Farm System" of yore, with a 32V battery or bank of cells, and if one was doing well a 32V gasoline powered generator to complement that, which is what my grandfather had.

The plate supply is 32VDC, and the type 32 and 21A filaments are individually operated via dropping resistors from this B+.

To confirm it, The dropping resistor value for each tube was added to the quotient of the filament voltage over the filament current, to give the total resistance. 32V divided by that number is equal to the tube's filament current. It would not be too wasteful if one has a large secondary battery that is kept charged by a gas or wind generator.

Figuring that bit out helped me with the pilot lamp identification (it is missing).

A spreadsheet was made up wherein one enters the battery voltage, dropping resistance, candidate lamp data: voltage and current. A column provides a degree of error for each case of the battery voltage, series dropping resistor, and lamp voltage and current data. The number closest to zero is the best bet, with negative values being preferable (lower voltage to the lamp)

That workbook is attached, perhaps it will help someone.

At this time, too many estates have caused the radio to be inaccessible, but it's still safe here and when I can get to it I can report on it further and maybe have a few pictures of it. Thanks to all who have helped about the tubes information and all.

BTW I recently found a "Talking House 5.0" part 15 AM transmitter. It sounds good, and there are some improvements to be done and mods on the web demonstrating the better audio quality afterward. Later on the PC can play oldies through it.

* pilot lamp divination.xls (21 KB - downloaded 81 times.)

* crescentdyne-sch-IMG_2523.jpg (330.44 KB, 1449x1103 - viewed 200 times.)
Logged

Radio Candelstein - Flagship Station of the NRK Radio Network.
Pages: [1]   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone © 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.057 seconds with 18 queries.