[AMPS] Suppressors, measurements, and acrimonious blather

[i4jmy@iol.it]

In case the resistance become very high or infinite, not only the 
suppressor doesn't work but there's an increased risk to have 
parasitics than without the damaged suppressor.
When amplifier power is large enough and the reactance of the 
suppressor coil is also high enough to produce in the resistor an RF 
current flow that's beyond its capability (more frequently it happens 
on 28 MHz), or the resistance rises until a balance point is found, or 
the resistor breaks (opens).
A large number of conventional suppressor one can see when opening HF 
amplifiers show a resistor that has been evidently overheated but a few 
people take the charge to measure what's the actual resistance of those 
burned resistors. 

73,
Mauri I4JMY



> ---------- Initial message -----------
> 
> From    : owner-amps@contesting.com
> To      : Fred Fliss <fredfffff@hotmail.com>, 
amps@contesting.com,   "'Paul Christensen'" <paulc@mediaone.net>
> Cc      : 
> Date    : Thu, 3 Aug 2000 13:47:08 +0100
> Subject : RE: [AMPS] Suppressors, measurements, and acrimonious 
blather
> 
> 
> 
> Paul says:
> 
> >the standard use of the classic coiled wire on a carbon composition 
resistor.
> 
> I have a nasty suspicion that one of the problems  with the classic 
suppressor
> is that the carbon comp resistor is pushed pretty hard in terms of 
dissipation,
> especially on the higher bands, by the fundamental current. Add to 
that fact
> that the resistor is in a high temperature environment as well, all 
of which
> isn't good for reliability. The result is that the resistor value 
goes high, and
> a suppressor that worked becomes a suppressor that doesn't work 
anymore.
> 
> 73
> 
> Peter G3RZP



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