[GreenKeys] Western Union Rectifier 69-B

[DR HOUSE]

Thank you Richard.  Good thing I replaced the 83 with the 83V

Best,
Don
K9TTY


On 24 Apr 2012, at 1:42 PM, Richard Knoppow wrote:


   Its given in the RCA Receiving Tube Handbooks.  My oldest is RC-14,  
from 1940, which has complete details on the 83 but the same advice is  
carried over into much later handbooks.  The advice is general for  
mercury vapor tubes and is also give for the 866/866A and 872/872A in  
the RCA Transmitting Tube handbooks.
   Where tubes have been in storage for a lengthy period, especially  
if they have not been stored vertically, its a good idea to sit them  
vertically for a day or so to allow the mercury to pool in the bottom  
of the tube. Then apply filament voltage only for a time, at least  
fifteen minutes and allow the tube to sit and cool again to pool the  
mercury. This makes sure no mercury has stuck to the elements.  After  
this the larger tubes should be operated for about five minutes with  
filament only before applying plate voltage.  The 83 was designed for  
use in receivers and other small equipment and may not need such a  
long warm up but I would give one at least two minutes of filament  
voltage before applying HV.
    There was a vacuum tube replacement for the 83 called an 83V, a  
dual diode with an indirectly heated cathode to reduce the voltage  
drop.  Its still not as low as the mercury vapor tubes but is enough  
to be satisfactory in many circuits. Especially when used in receivers  
the 83 tended to produce a lot of electrical noise or "hash" which was  
difficult to eliminate, the vacuum tube rectifier does not suffer from  
this so was more satisfactory when used in receivers and probably  
audio equipment. These tubes were supplanted by vacuum tube  
rectifiers, selenium rectifiers in some applications, and, of course,  
eventually silicon diodes.
   BTW, the RCA book states that darkening of the envelope is normal  
and does not affect the performance.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com