[R-390] Re: Crystal Oven Heater Resistance

[Mike Hardie]

Bob, Roy and group,

This HR202 unit is made by Blighly with a "TCO-21" designation, it also has 
"6.3 volts" and "1.0 amp at 75*C" on the tag.  Using ohms law the resistance 
of the element should be 6.3 ohms.

I took a look at the Y2K manual and the pinout reads element between pins 3 
and 1.  The resistance on this unit measures (With the VTVM on 10 ohm scale 
finally) 6 ohms, close enough for you-know-what.  The switch is shown as 
between pins 1 and 7, and on this unit the resistance measures a fraction of 
an ohm.  The connection from J208-F goes to pin 3 of HR202, throught the 
element and switch, to ground.

So I'm still stuck with why does the TM 11-856A manual state the resistance 
should a minimum of 100 ohms on J208-F.  I'm doing something wrong but what?

Mike VE7MMH