[Heathkit] Screen dropping resistors (was DX-100B on Phone - bad audio distortion /oscillation)

[lee]

Rick:

If they have two 10 watt resistors in series and you have 11 watts through 
the chain of 2, you only have 5 1/2 watts through each resistor as each 
resistor is dropping the voltage by 1/2 the total amount.  In other words, 
two 10 watt resistors in series gives you one 20 watt resistor.

Lee, w0vt

-----Original Message----- 
From: Rick Poole
Sent: Thursday, December 15, 2011 11:21 PM
To: heathkit at mailman.qth.net
Subject: Re: [Heathkit] Screen dropping resistors (was DX-100B on Phone - 
bad audio distortion /oscillation)

At 12:01 AM 12/16/2011, Don Cunningham wrote:

>>>>>
>On Heathkit stuff, especially early ones, you just HAVE to remember
>what everyone is telling you.  Heath bought up TONS of surplus parts
>in the 40's and 50's and used them in the kits.  The engineers often
>put odd values, and series'd or paralleled parts to make a circuit work.
<<<<<

Sure, they happened to have a jillion 10K 10W resistors lying around,
I get it.  But running 11 watts through a 10 watt resistor,
especially doing it essentially continuously (it's there whenever the
transmitter is in transmit, including during long, Long, LONG AM
monologues), and doing it in an environment where there isn't any air
movement to cool things down (underside of the PA section, very small
volume and completely closed in with no ventilation), is just plain
crappy engineering!  I thought Heathkit engineers were better than that.

Rick WA1RKT

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