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FF33 German field telephone wwii

Started by dsk, October 24, 2016, 04:09:53 PM

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dsk

Diagram:

The diagrams are based on diagrams in the telephones, various diagrams from the internet, and changed in hence of language to be readable in English.

Turn-ratios, are from the text on the induction coils.

unbeldi

Source:
German Field Line Communication Equipment of WW 2
Part II
Copyright © Funksammler Publications 2010 All Rights Reserved.


dsk

Drawings changed, to not violate copyrights.  The drawing used are modified drawings commonly known (scan from manuals from approx 1950), and not protected by copyright. 

The references over are good documentation, based on the same ideas.

dsk

unbeldi

Quote from: dsk on October 25, 2016, 03:26:39 AM
Drawings changed, to not violate copyrights.  The drawing used are modified drawings commonly known (scan from manuals from approx 1950), and not protected by copyright. 


That wasn't my point actually. It could be argued that use of a diagram represents fair use in a educational posting.
Ue of eBay pictures is probably a lot more controversial.

The point was to provide a reference for the material, as I knew the source when I saw the table.  The book is a great compilation.


unbeldi

#5
It is my opinion, in general, that posting diagrams without explanations, without context or source, is not very helpful in many, perhaps even most, cases.  For example, the TCI library is full of diagrams taken out of context without any explanation.  People seem to think that a diagram is the ultimate answer to some yet unknown question.
Many telephones come in a multitude of configurations, wired for various service requirements, and the circuits may be even evolve slightly over time, with changed components or component values. Many times a diagram taken from a catalog or technical reference shows only one configuration, and modifications are explained in prose and tables.

When posting a diagram, I think it should be accompanied by a description of equipment, application, service, time frame, source and whatever else someone might need to properly use the diagram. When I post diagrams, I try to summarize the equipment features, some history, and a general frame of context, such as related equipment, earlier, or later types.

When I encounter a diagram that has nothing with it, I most often simply discard it—well, it goes into a big digital bucket when it sits and waits—when I cannot determine its provenance, or even authenticity.  The TCI library, for example, is full of such examples. Elsewhere, one can also find compendia of diagrams without references, and it can be hard to link them to an actual piece of equipment, unless one find the exact diagram in another phone. For example, I have spent enormous times in unraveling a compendium of Kellogg diagrams, and still have not accounted for even the majority of them.  One would think it would have been trivial to the originators to write a few sentences about the history of each of those documents. Without that it becomes a waste of time for everyone, one cannot use the diagram for historical studies, unless one finds the same diagram again on a telephone.

dsk

I see that point, even when I have had great benefit of those TCI documents.
I have trusted them in being real, but I'm also aware of variants has been made.

E.g. my 193x 202 or D1 made by Associated Telephone company LTD with AE dial.

dsk

dsk

Still learning:
Facebook group: WWII German Signals and Communications Equipment

dsk

I made a reference diagram for using an ohm meter to test between the terminals. If your metering shows results far from this it may be something wrong.  will probably be OK with anything more than  1 000 000 ohms.

dsk

I did measure on the handset plug too, and the values are within what I had on this and other.
The most common receiver is 70 ohms, but different units has been used during the years of "care".
The transmitter-capsule will depend of position among others so measuring has a limited value.

The best way of testing is real speech test.  One way is to put in a strap and a battery. When you use a 9V battery as on the picture this is far to much for long testing, but compensates for high resistance receivers.  On most transmitters the battery polarity does not matter at all, a few transistorized capsules will not work with wrong polarity.

If you need to put in a regular CB (=OB) transmitter capsule in an LB telephone you may compensate by rising the voltage.  The important thing is to limit the current. On these with original transmitter she current should be around 20mA and 50mA will slowly destroy the transmitter capsule,

dsk

I made a reference diagram for using an ohm meter to test between the terminals. If your metering shows results far from this it may be something wrong.  will probably be OK with anything more than  1 000 000 ohms.  The only difference from earlier post is the + /1 polarity is changed to be according to most chemtics available. The polarity does not matter for the metering, or for the use with a traditional carbon transmitter.