[Test-Equipment] door knob caps

[Bob Roehrig]

On Mon, 23 Jul 2007, WB6BLV  Central California wrote:

> Not sure why the warning bout not using these caps in tuned circuits or as
> bypass or feedthrough as I have used them in QRO amps for decades with no
> difficulties whatsoever.  If the capacitance measures close to the marked
> value they are almost always OK.  I have never had one go bad nor have I had
> one turn out to be bad if it measured as marked in capacitance.  Just my
> $.02...

OK JOhn. Well that at least was my experience with them. I can't remember 
but I think I tried one 500pf unit across a variable cap in a transmitter 
tank and it went "poof". Now this was a pullout from a TV set, rated at 
20KV.  I know the Centralab ceramic units that kind of look like doorknobs 
are just fine. I'd be interested in knowing what luck others have had with 
the standard TV doorknobs.


                               Bob Roehrig
                     Aurora University    Telecom dept.
                            broehrig at aurora.edu
                          K9EUI  W9ZGP  WD2XSH/19
                     630-844-4898      fax 630-844-4222
                     "Nostalgia is a thing of the past"