Classic Rotary Phones Forum

Telephone Switching => Magneto & Manual (Cord Boards etc) => Topic started by: Fabius on June 01, 2018, 12:50:00 PM

Title: Stromberg Carlson Military Switchboard
Post by: Fabius on June 01, 2018, 12:50:00 PM
Stromburg Carlson SB22/PT military portable switchboard. Made for the US Army Signal Corp. Vietnam era. Bought on eBay for $185 with free shipping. Seller accepted my best offer.

One reason I picked this switchboard was that it was in active military service about the same time as myself.

Also it still had its original ID tag on it. Many you see are missing this tag because whoever "liberated" it would remove the tag.
Title: Re: Stromberg Carlson Military Switchboard
Post by: dsk on June 01, 2018, 01:07:58 PM
I used the SB 22, when I served, but it had only one Jack at the operators pack.

Nice piece!

dsk
Title: Re: Re: Stromberg Carlson Military Switchboard
Post by: Fabius on June 01, 2018, 02:41:03 PM
I used the SB 22, when I served, but it had only one Jack at the operators pack.

Nice piece!

dsk

Thanks. Were you in the Hæren? (Army)
Title: Re: Re: Stromberg Carlson Military Switchboard
Post by: rdelius on June 01, 2018, 04:10:40 PM
When military electronics were disposed of .demilling rerquired tha id tags , meters  etc were distroyed.
Title: Re: Re: Stromberg Carlson Military Switchboard
Post by: dsk on June 01, 2018, 04:32:59 PM
Thanks. Were you in the Hæren? (Army)

The coastal artillery (??)  We had one at each canon for the postitions around,  one switchboard connecting all the SB22 ++ except for one position where they had an x-german 10 line wartime exchange:  https://goo.gl/BPDjqj (https://goo.gl/BPDjqj)

I have the German type, but have not got the SB22. (mainly because I'm not willing to pay what it costs  8)    )


The SB22 did not connect to the automatic system, the system (installed 1982) did not understand touch tones.

dsk
Title: Re: Re: Stromberg Carlson Military Switchboard
Post by: Fabius on June 01, 2018, 09:21:32 PM

I have the German type, but have not got the SB22. (mainly because I'm not willing to pay what it costs  8)    )


High demand. I think the price is high because of all the veterans who want one.

I notice that there are some from Europe on eBay. I recently seen one in Poland and one in England. Maybe postage would be low since Norway is in the European Economic Area?
Title: Re: Re: Stromberg Carlson Military Switchboard
Post by: dsk on June 02, 2018, 07:00:44 AM
Those we had was made in USA, The European ones are modified with a clumsy connector, and a rotary dial.

dsk
Title: Re: Re: Stromberg Carlson Military Switchboard
Post by: rdelius on June 02, 2018, 10:56:12 AM
This set appears to be modified to fit  a type 52? headset.I  it should have a large connector for the  headset
Title: Re: Re: Stromberg Carlson Military Switchboard
Post by: Fabius on June 02, 2018, 03:26:12 PM
This set appears to be modified to fit  a type 52? headset.I  it should have a large connector for the  headset

I noticed that. When I get time I plan to you thru the various manuals and see if this mod is listed. It appears to be factory or an update by an Army maintenance depot.
Title: Re: Re: Stromberg Carlson Military Switchboard
Post by: rdelius on June 02, 2018, 03:42:31 PM
I have had several sb22 boards and none have had this headset mod
Title: Re: Re: Stromberg Carlson Military Switchboard
Post by: dsk on June 03, 2018, 03:15:39 AM
Never seen that in any TM.

Some info here: http://www.prc68.com/I/SB22.shtml
http://radionerds.com/index.php/SB-22~PT
http://www.liberatedmanuals.com/TM-11-5805-262-20P.pdf
Title: Re: Re: Stromberg Carlson Military Switchboard
Post by: Fabius on June 03, 2018, 12:43:15 PM
I emailed the owner of that SB22 web page if he had ever seen that mod.

I've started to take a look at this switchboard. I was surprised to see a large part of it is made of aluminium such as much of the housing and some parts of the various plug in components face plates. The plate (silver color) of the mod being discussed is also aluminium.

While the housing has paint loss, what I've seen so far of this unit is that in may be new or saw very little use. The battery compartment, battery holding tube and wiring connectors are mint. So is the inside of the top where the headset is stored. All lettering and instructions on the metal and components are intact.

The headset is marked Western Electric 53. And is dated 1961 in several places.

This evening I'll remove the operator module and get a better look at the jack modification. So far I have not seen any Army refurb stamps. These were a orange color triangle with the date.
Title: Re: Stromberg Carlson Military Switchboard
Post by: rdelius on June 03, 2018, 01:59:00 PM
The older SB22s are almost all aluminum,  Later ones are of a plastc mareral
Title: Re: Stromberg Carlson Military Switchboard
Post by: Fabius on June 03, 2018, 07:45:19 PM
The older SB22s are almost all aluminum,  Later ones are of a plastc mareral

Thanks, didn't know that.
Title: Re: Stromberg Carlson Military Switchboard
Post by: Fabius on July 07, 2018, 11:41:06 PM
One of the things I notice about the operator pack on my SB22 is not only does it have a mod for a regular type headset but notice that the 310 jack at the top left is not there. Not covered up, no hole, just not there. Also on mine there is no nomenclature above the magneto crank. Every operator pack I've looked at with Google Image has the 310 jack and the nomenclature. 
Title: Re: Stromberg Carlson Military Switchboard
Post by: rdelius on July 08, 2018, 12:52:49 AM
Besides the missing jack, the cord is retractable. The operators pack  usually has the mounts for a retractable cord but no mechanism
Title: Re: Stromberg Carlson Military Switchboard
Post by: dsk on January 29, 2019, 01:44:28 PM
Now I have line-packs, I just need the rest of it  ;D


dsk
Title: Re: Stromberg Carlson Military Switchboard
Post by: dsk on November 13, 2019, 12:19:00 PM
Now, I know a little bit more.
The older operators packs had that retractable cords, but no jack for resting the plug. 
The handset jack is obviously switched out by some reason.

When I served we did not use the headset, but a handset: H-33 handset.

My guess is that the mod here are made for using a handset the owner had.

dsk
Title: Re: Stromberg Carlson Military Switchboard
Post by: dsk on January 06, 2020, 12:14:44 AM
Now I have got my own SB22  ;D   and some mor info might be there, at least a wiring diagram.
http://www.classicrotaryphones.com/forum/index.php?topic=22631.msg232631#msg232631
 (http://www.classicrotaryphones.com/forum/index.php?topic=22631.msg232631#msg232631)
and
http://www.classicrotaryphones.com/forum/index.php?topic=23149.msg232650#msg232650

dsk
Title: Re: Stromberg Carlson Military Switchboard
Post by: Fabius on January 09, 2020, 08:50:56 PM
Does yours have the tag that shows who made it? If so, who made it?
Title: Re: Stromberg Carlson Military Switchboard
Post by: dsk on January 10, 2020, 12:49:54 AM
SC(http://www.classicrotaryphones.com/forum/index.php?action=dlattach;topic=22631.0;attach=208176;image)
Title: Re: Stromberg Carlson Military Switchboard
Post by: dsk on April 15, 2020, 08:06:39 AM
Now I have used it for a while, and it was definitely not 100% OK, but it took time to discover some of the problems.

The first I had to do was to change the cord and plug, the cord was weared out.  (6)
The next was some problems I believed was in the switches so I measured and got some resistance.  (5) Cleaning with plain paper dipped in alcohol and keep the contacts closed.  Helped a lot!

Some later I found that the ring and sleeve had no connection.  The fault was the switch inside the generator (4)
What else have I heard others having problems? The Capacitors (2) and (3)  are also weak points, First aid suggestions: The no C301 (2) will just remove the anti sidetone, and you will probably barely notice it.  C302 (3) will make you loose the contact to the handset.  Without using a tone sender or field telephone to the contacts "EMG OPR" it will probably mean nothing to short C302 until it may be replaced of any unpolrized capacitor of 2-4 uF  rated at least 50V  If you can not get power to the transmitter it is most likely in outside the operators pack, often in the battery holder, and somtimes in the handset/headset with cords.  I can see a possible problem in the rest jack, but find that not so reasonable since those jacs are tough.
dsk
PS I really hope it works OK from now  DS
Title: Re: Stromberg Carlson Military Switchboard
Post by: dsk on April 16, 2020, 07:07:46 AM
Since it seems to be impossible to get the original DTMF unit for the cordboard, and my trunkpack also is a DIY version, I did get inspired of the German WWII solution: http://www.classicrotaryphones.com/forum/index.php?topic=22478.msg226592#msg226592 (http://www.classicrotaryphones.com/forum/index.php?topic=22478.msg226592#msg226592)
(http://www.classicrotaryphones.com/forum/index.php?action=dlattach;topic=22478.0;attach=205640;image)

But of course I would like to have touch tone too, so I found a scrap phone with tone/pulse selector.   I did put in a jack, and some components.   I prefere the transformer to get the systems isolated from each other, the small transformer does not like the DC components, so I did put e capacitor in series on the CO side, and added a 470 ohms resistor to keep the DC path without loosing to much of the signal. On the SB-22 side I also added a capacitor to prevent it from stealing all the ring off power.

The diagram sketch shows how I wired it.  And ofcourse you have to see how small the transformer actually is.

The best of all, it woorks great on first try.
dsk
Title: Re: Stromberg Carlson Military Switchboard
Post by: dsk on April 16, 2020, 07:12:32 AM
I also have to say thank you to Brooke Clarke who has great pages with information:
https://prc68.com/I/SB22.shtml (https://prc68.com/I/SB22.shtml)

He actually also links to this page  :)

dsk