"The phone is a remarkably complex, simple device,
and very rarely ever needs repairs, once you fix them." - Dan/Panther

Main Menu

ZB W24F - A phone I've wanted for a long time

Started by tubaman, March 09, 2019, 04:08:07 AM

Previous topic - Next topic


As per the title I've wanted one of these for a very long time and have finally got one.
It's certainly not pristine, but is what I would call a nice honest example - it was €69.50 + €17.99 postage (£78.53 after conversion).

Altes Telefon mit Wählscheibe. Zustand: Gebraucht Sammlerstück !
Laut innen liegender Stromlaufplan ist es ein SA 24 F. Das SA ist mit einem roten W überstempelt.
Die Fingerlochscheibe ist aus Messing verchromt.

Goggle translates to - Old dial-up telephone. Condition: used collector's item!
According to the circuit diagram inside it is a SA 24 F. The SA is stamped with a red W.
The finger hole disc is made of chromed brass.

As the seller said the diagram is 'SA 24F' with the 'SA' overwritten with a 'W' - and the label on the base is indeed 'W24F'. I'm not really sure what the difference is.
Some work was certainly done to this in the '50s as the the transmitter capsule has been 'upgraded'.  Apart from that it all looks nicely untouched.
The dial runs with a gorgeous sound and makes a satisfying little clunk as it stops.  It also locks when the handset is on hook - a feature I've only seen on German phones.
Any more info on this phone would be much appreciated.


More photos.
The 1980 1 pfennig coin was wrapped in the play money inside the base when I opened it.  Some child had clearly thought it a good place to put it!


Doug Rose

Tubaman....thanks for posting your phone. I have one and never knew what it was.....Doug


Yours has the rather more practical transmitter cap.  I really like the horn on my one but imagine it would be very easy to break.


I've been doing a bit more research into why the diagram has 'SA' overwritten with 'W' and have found a clue on a German site -

(Translated by good old Google)
In the table of contents of the "Wiring diagrams for intercom equipment of the German Federal Post Office" (1) can be found at the beginning the following remark: "For technical printing reasons, the correction of the name SA in W had to be omitted within the circuit diagrams". In the following table of contents, only the designations W 19 or W 24 are used for the corresponding apparatus...."

Perhaps one of our German members can take a look and do a better translation?

I do wonder if 'technical printing reasons' is a euphemism for 'we only noticed it was wrong after they were all printed'.  ;D


I'm not German and look forward to comments on that too, but I believe The W came when it was approved by the telephone authorities in Germany.  (It looks like Germany as many other countries in that area had a common postal and telco monopoly.)

Another excample on this W thing is the W28 was approved, the modell 36 Was not, but the W38 was...



I'll try to shed some light into German bureaucracy :)

Doing that from my memory, maybe I have to double check later.

At first it was the German Reichstelegraphenverwaltung RTV, later the Reichspost RP and after the war the Deutsche Post DP (East Germany) and Bundespost BP (West Germany). The latest I have heard the term ZB Zentral Batterie (central batterie) SA -some say Selbstwähl Anschluss (self dialing connection) but if I remember right it stands for Selbsstanschluss Amt (selfdialing central office) is up to 1928 for the model 28 or more commonly known W28 when changed into W (Wählapparat- dial apparatus). Officially ZBSA changed to W in 1924. And to even more complicate it- after the war the W in East Germany was still for Wählapparat, in West Germany it was Wählfernsprecher (dial telephone).

About the German article and the translation confusion- it says that only in the diagrams, due to technical printing reasons it was not changed from ZBSA to W but in all other text it was. Confusing? A bit maybe :)
In real world, for everyone involved into telephone business both terms where understandable anyway. At least in the 1950's when printed.

As you can see from that little cardboard piece, your phone was revised (if I remember right, that is what the J stands for) and has a Reichspost RP stamp from 1939. Your transmitter horn belongs to an OB 06 (have to check that) handset, used for the model OB 06 phone to the model ZB SA 19. Dougs cap is the correct one. Your dial should be stamped N (Nummernschalter) 24 somewhere. Very nice phone you got :)





Thanks for the information - very interesting.
I assume the cardboard piece you mention is the one in the transmitter. I have taken a better look at that and it has '19 Dez 1958' stamped on the back of it, so I wonder if that was when the transmitter was revised, and possibly when the horn type transmitter was added?  I have seen quite a few photos of other examples with the same horn so I don't know if they were using up spare parts.
As for the dial, my one has 'N30' stamped on it (you can see it if you enlarge the photo) so is that a later version?

Doug Rose



Quote from: Doug Rose on March 16, 2019, 07:58:54 AM
Some info on this expensive phone...Doug

Rare it may be, but not nearly $500 rare!

Doug Rose


Sellers interesting description:

Vintage 1930. First Estonian table Telephone . Very Rare !!

Was produced by Tartu Telefoni Vabrik A/S factory in Tartu (Estonia).

The factory was founde in 1907 (Edisson Kompagnie Co).

From 1930 the official name Tartu Telefoni Vabrik A/S.

In 1940 the factory was nationalized, 1941 - 1944 was destroyed.

Number       : № 436 253 (From A.B.L.M. Ericsson)

Model          : №308 a / №309a

Prod. years  : 1930


The question why both ZBSA24 and W24 are applicable names has been answered above.
For completion, the F stands for Funkenlöschung, arc suppression. Earlier versions used the second contact of the hookswitch to put the ringer in parallel with the transmitter to prevent dropping the line, should contact problems inside the transmitter occur. The later "F" versions had a better transmitter and used the second contact to put a 100 Ohm resistor in series with the ringer capacitor and both in parallel with the pulse contact for arc suppression. This principle was retained until the end of rotary dials in German phones.
See diagrams in the German forum