[Boatanchors] Dow key relay identification?

[Garey Barrell]

George -

The "isolated" relays have a longer connector body on the receive (NC) 
side.  The center conductor on the longer connector is actually two 
pieces that are spring loaded so that they separate when the relay is 
energized, giving a "double-break" and higher isolation.  Also check 
that the receive side center pin actually moves if you press on it with 
a probe from the inside.   Before you use either one, pull the hole plug 
out of the end and look to ensure that there is space between the 
contacts.    I have seen too many cases where someone has screwed the 
"side" connectors in far enough that the movable contact is trapped 
between the two "fixed" contacts.  Hard on the receiver!

73, Garey - K4OAH
Atlanta

Drake C-Line Service Manual
<http://hr99.home.mindspring.com/R-4C_Servicez/>



George KB2Z wrote:

> Can anyone tell me how to tell if a  Dow key relay is isolated for 
> tx-rx use? I have 2 that seem identical
> DK-60 type. The DK-60 (G) isolates the rx on transmit. I have been 
> using one for a long time with no problems. I got it with a pair of 
> Halli's.  The second one I have looks like the one I'm using. The only 
> marking on both is 110v on the coil.  The casings for both are black 
> in color. I want to use the second one for a tx-rx but dont know how 
> to tell if its safe to use.
> Thanks in advance, George KB2Z
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