608 



THE BELL SYSTEM TECHNICAL JOURNAL, MAY 1953 



senders wdth 6,000 solderless connections has been in service about nine 

 months, again vdth no troubles reported. 



In order to test these connections in a transmission circuit one channel 

 of the K-1 carrier system between Newark and Atlanta was selected. 

 Rather than ^^dre a regular equipment unit with solderless wrapped 

 connections, four units were built consisting of two groups of 320 con- 

 nections in series. Each unit was exposed to 15 weeks at 85°F 90 per 

 cent relative humidity and then inserted in the system. One unit was 

 located at each of the following places: New York, Philadelphia, Balti- 

 more, and Richmond. No troubles or adverse service reactions have 

 been received to date, more than six months after installation. 



SUMMARY 



The tests described indicate that solderless wrapped connections are 

 practical when wrapping No. 24 solid tinned copper wire on fiat punched 

 terminals of brass or nickel silver where the mdth is one-sixteenth inch 

 and the thickness varies from 0.010" up to one-sixteenth inch. Similar 

 tests with heavier wire, (No. 20 to No. 23) such as would be used in 

 distributing frames and tests with No. 24 wire on flattened, coined, or 

 otherwise treated wire spring relay terminals have also been successful. 

 These connections are mechanically stable, and have less tendency to 

 break due to handling and vibration than solder connections, and will 



e = f L(R,) 



2B NOISE 

 600n<' MEASURING 

 SET 



son 



vw 



(a) MEASURING CONDITION 



60on. 



Vr= 



2VB-4' 



(b) subscriber CONDITION 



Fig. 13 — Comparison of noise measuring circuit with subscriber circuit. 



