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Majestic-7 71 Ch= 70 - 7A

Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 643733) Radio
 
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 644074) Radio
 
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 676667) Radio
 
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 676668) Radio
 
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 676669) Radio
 
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 676670) Radio
 
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 676671) Radio
 
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 676672) Radio
 
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 676673) Radio
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 1421448) Radio Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 1421461) Radio
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 1076729) Radio Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 1076728) Radio
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 643076) Radio Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 643075) Radio
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 643074) Radio Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 632404) Radio
Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 631612) Radio Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 632401) Radio
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Majestic-7 71 Ch= 70 - 7A; Grigsby-Grunow Co., (ID = 1421448) Radio
Grigsby-Grunow Co.,: Majestic-7 71 Ch= 70 - 7A [Radio] ID = 1421448 933x1238
Select picture or schematic to display from thumbnails on the right and click for download.
For model Majestic-7 71 Ch= 70 - 7A, Grigsby-Grunow Co., (pre 1933):
By courtesy of EBAY Seller: byronhoff
 
Country:  United States of America (USA)
Manufacturer / Brand:  Grigsby-Grunow Co., (pre 1933)
Year: 1928 Type: Broadcast Receiver - or past WW2 Tuner
Valves / Tubes 8: UX226 UX226 UX226 UY227 UX226 UX171A UX171A 280
Principle TRF without reaction (non reg.dir.receiver); Neutrodyne
Tuned circuits 4 AM circuit(s)
Wave bands Broadcast only (MW).
Details
Power type and voltage Alternating Current supply (AC) / 90-130 Volt
Loudspeaker Electro Magnetic Dynamic LS (moving-coil with field excitation coil)
Power out
from Radiomuseum.org Model: Majestic-7 71 Ch= 70 - 7A - Grigsby-Grunow Co., pre 1933
Material Wooden case
Shape Console, Lowboy (legs < 50 %).
Dimensions (WHD) 27 x 46 x 15.5 inch / 686 x 1168 x 394 mm
Notes This is the early version of Majestic model 71 from 1928. See also the later version from 1929 with quite a different housing and chassis version 7B. We have found a picture of the later version as a low boy but are not sure if there is also a high boy with chassis version 7B - and vice versa. The difference can be seen on the plate: Here you find the chassis Majestic 7, model 70 in the version 7A. This set and the late version have a push-pull output stage using two 171A power tubes, later called 71A. The Majestic 71 is made of walnut with burl walnut front panels and came with a Majestic electric power unit and Majestic dynamic power speaker. But see also the minor differences between Majestic ads and the actual set. The Majestic 71 (early) uses the Majestic Power Speaker model G-1 (for receiver models 71-89) of about 8 1/2" diameter. The legs are 192 high. The set weighs approximately 80 to 90 pounds.
Price in first year of sale 137.00 $
Collectors' prices  
External source of data Ernst Erb
Source of data Radio Collector`sGuide 1921-
Circuit diagram reference Rider's Perpetual, Volume 1 = 1931/1934 (for 1919-1931)
Mentioned in The Radio CollectorGrinder, 1995
Literature/Schematics (1) Grigsby-Grunow 1928 Flyer

All listed radios etc. from Grigsby-Grunow Co., (pre 1933)
Here you find 193 models, 109 with images and 154 with schematics for wireless stes etc. French TSF for Télégraphie sans fil.

 


Forum contributions about this model
Grigsby-Grunow Co.,: Majestic-7 71 Ch= 70 - 7A
Threads: 1 | Posts: 9
Hits: 2373     Replies: 8
grigsby-g: ; Majestic 71 - Why such work is very essential
Ernst Erb
27.Jun.09
  1

Dear Readers
I'm amazed of the work a very few Americans do here.
I write "Americans" because also Meyer Rochweger from Brazil is contributing very much. The two top members from the USA are Thomas Albrecht and now Robin Roeckers who also helps as model admin. Thomas has done a tremendous work on Philco models and thanks to him and Gidi Verheijen we show  Philco 2570 models. Thomas is on the board of directors. Both help very kindly if a member has problems facing the needs of quality in Radiomuseum.

Pictures from an original catalog
from the time the model was sold

I would like to show why primary sources are so essential. In this example Robin Roeckers scanned a catalog from Grigsby-Grunow from a 1928 brochure.

We can never say: "Exactly like this it must have looked" because sometimes the manufacturers change small details - and sometimes the set never gets sold!

But still: Original documentation from the manufacturer/brand is the best source. Essential too is to state which source has been taken and from when it is.

I was wondering if I find some more data or the tube line up to complete this model a bit and Googled. Then I first fell on this picture here:
 


http://www.antiqueradios.com/gallery/v/Majestic/Majestic_71.jpg.html
 

Sorry, I did not find anything more than this picture about this set - so different in appearance - but maybe it is the model 71 from 1929 with chassis 7-B. So I just want to show you that details really matter and that our approach is a different one to others: All combined on one spot with information, pictures, schematics and links to the manufacturer/brand details, tube details etc. - and those again with links to replacements etc.

I then found an eBay offer just running and asked if we may publish those pictures. They show us the chassis, name plate and "our" set ...

Since we have all the original Biders of Riders I found also the schematic under Majestic but in the order of Grigsby for Majestic 1-1 followed by details about the power pack 7-P-6 and 7-P-3, both old and new wiring (3 sheets), followed by the schematic for 70-B etc. and at 1-24 there is details about the coding of 1928 and 1929 models. Be careful: There is also the tube line up - but for other models ...

The Rider's binder "Abridged Volumes 1 - 5" does show models 60, 61 and 62 from this sheet 1-24 on page Grigsby 18 but I did not find model 71 (nor under General Household Utilities Co. - Grunow). Fortunately I have also the very first binder - yet without a number - and on page 373 there is the schematic and tube line up of the early model 70 from Grigsby-Grunow Co., drawn 7th November 1928 (figure 18) with a note: "Prior DRG 7-9-28". "Wiring Diagram for # 70-7 tube receiver 9-1W. Is that the right line? I can not yet say. It shows the tubes 3 x UX226, UY227, UX226, 2 x UX171A and 280 - or 3 x CX326 (CX-326), C327 (C-327), CX326 (CX-326), 2 x CX371A (CX-371A) plus the power unit with the CX380 (CX-380).

In General: 
There is still much to do for this manufacturer Grigsby-Grunow Co. and its brand Majestic: At the moment we have spread the models for the two names: 181 models on Grigsby-Grunov pages before 1933 and 265 models on Majestic Radio & Television Co. pages, starting in 1933. Konrad Birkner started a clean up article by beginning with: "Majestic is a name of multiple use. There is terrible confusion in literature about three separate companies. To avoid doublets ..."

Please help us in our effort to give you very precise information about the old time or antique radios by telling where we miss something or where we are in error - by delivering solid proofs. Guests can send such information via contact form

I see our common work as an ant colony (ant hill or ant state) - with much iteration until we find the truths - but hopefully always with good references (which might be wrong) and double checking with many different sources (but not just copied stuff from each other ...). A very hard job. Who will try to work on a brand methodically?

I bought some more original catalogs and I would send them to somebody who likes to do scanning. After that work of uploading he/she can keep or resell for his/her own benefit. We also have many original SAMS Photofact to give away in this way.

Ernst Erb
27.Jun.09
  2

I consulted the "Official Radio Sevice Manual and Complete Directory of all commercial wiring diagrams of receivers" from Hugo Gernsback (Editor) and Clyde Fitch (Managing Editor), a smaller binder with Copyright notice 1930.

On Page 190 there is one Grigsby-Grunow Co. schematic for models 60 - 70 & 80 with the same tubes mentioned. There is a note: "In some models of the "70' " the center-tap of the detector filament connects to the center-tap of the RF tube filaments, and the detector plate potential is then only about 30 volts.

Ernst Erb
29.Jun.09
  3

I uploaded the pictures from the mentioned eBay offer.
They also show us the plate. We don't have to wonder if this model is also referred to as Majestic model 70 or 7 or 7A.

See the writings on the plate = chassis designation - not model designation:
You find the number 70 for the general CHASSIS MODEL (for different housings etc.) and Majestic-7. The serial Number is pre stamped with 7A (chassis version early) - but the set is a Majestic 71 - the early version.

Please compare also the different details on the case between an actual set and an ad. I wonder if there are even two versions of this old model or if it is cheating ... 
It would not be WYSIWYG = What you see is what you get.

I wonder how many of us and how many guests can estmate the difference of the approach for finding and storing as many details about a model in a joint effort to get a most complete catalog and a reference work. But this will only function very slowly and with more of your time investment! The work in front of us is huge!

Isn't it fruitful for all of us if every member at least does something for RMorg instead of ONLY hiding boxes or ONLY repairing what is not needed anymore?

Ernst Erb
30.Jun.09
  4

This model has been on eBay as item number: 190316344536
I made a bit to communicate with the seller (he did not answer) - and this only bit won the model for $ 9.99.

It is not a piece I would like to ship to Switzerland. It sits in Boston MA.
Is anybody interested in it?
If not: Can anybody take out the chassis incl. scale and knobs and loudspeaker?
It is in any case a very rare and early loudspeaker ...

In case it is possible, please answer here or write to me by using the link "Mail to the Author" - very soon ...

The seller wrote: "it hummed but I could not get any stations to come in .." I wrote to a member nearby in Somerville, MA which is 5 miles apart ... Hopefully he has some interest - or is willing to pack or dismanttle for an other member ...

John Roux
30.Jun.09
  5

Hello Ernest,

I sent an email to you earlier. I wasn't sure if I should respond here as well, so I figured I would to make sure I covered all the bases.

If you need my help with this radio, let me know. I'm only a few hours away from Boston. I can pick it up for you and ship what you need.  Quickest way to get back to me would be my email address. I check that with more frequency than anything else.

Have a great day,

John

Ernst Erb
03.Jul.09
  6

Dear John
Thank you for your kind offer. I'm glad that you can fetch the interesting set.
It is then yours for reselling ;-) We all will just be glad to have additional data from it - but that we do by eMail.

My browser starting page is the link on the main page "New pictures". 
I was very happy to see that at least one American did take up my suggestion to post scanned pictures form leaflets or a catalogs, giving also reference for the right dating.
It is Robert Higgins with pictures for Motorola 51F11, 51F12 etc. from the Motorola catalog 1942. If a member does upload not only from his collection then it shows a general interest for our big source we share together. He thinks for us all ... He will not be the only one - but as an example I would like to thank Robert here. A catalog picture - if the catalog is dated - is also then most welcome if there are other pictures. It is some sort of a date proof.

Here is some data about our activity. About our struggle you see here more - at post 27.

John Roux
03.Jul.09
  7

Hello Ernest,

I spoke with the seller of this radio this morning. He is on vacation for the holiday weekend.  I will be able to pick up this radio at some point early in the week. I will have it here by Wednesday at the latest.  I will be leaving Thursday for a few days to visit my brother in Washington DC and will be back in town on the following Monday. 

Whenever you are ready you can let me know what photos, information or whatever you would like me to get from this radio, but as you said we can do that through email.

Have a great day. I will be in touch.

Robert Higgins
03.Jul.09
  8

Hello Ernest - Thank you for your kind words.  It is a real pleasure to take part in the Radio Museum.  The dedication and professionalism of the members is impressive and I consider it to be a privilege to participate.  Vacuum tube electronics has been an interest since I was a teenager.  Combine that with history and photography, and the Radio Museum is the perfect hobby.

Robert

Ernst Erb
28.Oct.10
  9

Since years we have implemented a unique method to be warned if a model is entered with a too early year - but we never have corrected some errors of before.

We have now programmed a red warning to the model page if that is the case and we can click a list of incorrect model dating or incorrect tube(s) / valves / semiconductors. At the moment it is 1686 such models, less than one percent of the model total - but still annoying. This list is found by clicking the link "Wrong dating or tube(s)" on the main tube page (tube search page).

The corrections have to be done by no hurry but by knowing members who can judge well which case is involved:

1 The model date is incorrect (too early):
   This is mostly the case because collectors want to see their set as old as possible ...

2 The tube date is incorrect (too late):
   Only a tube admin can put in dates and only the superadmin can change a given date.

3 Sometimes schematics etc. show later tubes, not the original tube line up:
 
Typical example USA: 1929 the UY-224 (224) is introduced.
  1932 this tube is updated with a shoulder-type envelope and is called 24A.
 
4
The model has multiple versions with changes in the tube line up:
   Very rare cases. 

5 Incorrect tubes were reported from a set that had been modified to use different tubes than
   the original tube line up.


This all has to be counted for if we decide the action which should be taken.
A detailed instruction follows below the list of incorrect dating - which can be sorted in different ways.

You also find the list of tubes which have been dated (yet only 1842) and a list of such semiconductors. We need more input from primary sources.

After having done this job (and in parallel) we should try to rename tubes for many models where we were misguided. We should give the models really the original tube line up.

There is also a later project to unify in some way the different envelope types like 6V6 6V6GT and 6V6G. At the moment we have for this example of the 6V6 in total 1365 models using it, for 6V6G there are 1683 and for 6V6GT are 2799 - not to forget the few 6V6GTA and all others we get by searching for 6V6.

To most collectors this might sound silly, I know. But we try to be (later) a real reference work.
See also how we could bring in very useful information to each model by looking to one example. This forum article about RCA 621TS repair and restoration sticks to the model and can be accessed by the forum or the model. Many collectors have helped beforehand and it would be beneficial for all, the two sites and the collectors (to get more information) to put a link here and there. I asked Alan Voorhees and will wait first for his decision. Surely this will not be used much because it is quite some work to compose a summary.

I know that only very caring collectors will work for building up a reference work (not only a catalog). In the last few weeks some active members from the USA joined - like Alan Douglas (author of books) and Alan Larsen - and others. I hope by reading all this, some more active members will join - or guests send us information using the contact form.

 
Grigsby-Grunow Co.,: Majestic-7 71 Ch= 70 - 7A
End of forum contributions about this model

  
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