KPA100 Final Transistor base resistance

[w9cf]

My daughter and I are slowly assembling a KPA100 Rev C.  We are at the
alignment and installation resistance checks, and the bases of Q1 and Q2
measure 11.4 ohms. The manual gives 12-16 ohms. Looking at the schematic,
it seems that the resistance for Q2 base should be the resistance of R9
(10 ohms) in series with the combination of R20 (1.6 ohms) in parallel
with the series combination of R34 (10 ohms) and R19 (1.6 ohms). This
works out to 11.4 ohms.  5 percent tolerances all working together might
get this to 12 ohms, but its hard for me to see how anyone would ever
get a resistance in the specified range.  Am I missing something or is
the manual wrong?

73 Kevin w9cf
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[Don Wilhelm-3]

Kevin,

You are OK - check the Rev D manual and its errata sheet and you will find
the range has been changed to 11 to 16 ohms.

73,
Don W3FPR

> -----Original Message-----
>
> My daughter and I are slowly assembling a KPA100 Rev C.  We are at the
> alignment and installation resistance checks, and the bases of Q1 and Q2
> measure 11.4 ohms. The manual gives 12-16 ohms. Looking at the schematic,
> it seems that the resistance for Q2 base should be the resistance of R9
> (10 ohms) in series with the combination of R20 (1.6 ohms) in parallel
> with the series combination of R34 (10 ohms) and R19 (1.6 ohms). This
> works out to 11.4 ohms.  5 percent tolerances all working together might
> get this to 12 ohms, but its hard for me to see how anyone would ever
> get a resistance in the specified range.  Am I missing something or is
> the manual wrong?
>
> 73 Kevin w9cf
>

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[Darwin, Keith]

Maybe.  When I did my Rev D KPA100 a few weeks ago, only ONE of the resistances was changed to read 11 - 16 in the errata.  The other still said 12 - 16.  Maybe the errata has been update in the last few weeks?
 
In my case, both transistors measured 11.5 ohms and the rig works fine.
 
73!
 
- Keith N1AS -
- K2 5411.ssb.100 -

________________________________

From: [hidden email] on behalf of Don Wilhelm
Sent: Sat 12/23/2006 12:25 PM
To: Kevin Schmidt; [hidden email]
Subject: RE: [Elecraft] KPA100 Final Transistor base resistance



Kevin,

You are OK - check the Rev D manual and its errata sheet and you will find
the range has been changed to 11 to 16 ohms.

73,
Don W3FPR



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[Ron D'Eau Claire-2]

For some reason the latest Errata hasn't been posted to the web site, but it
should be shipped with the kits (D-4, December 2, 2006). In any case, the
11-16 ohm spec is correct for both Q1 and Q2 base to ground.

Ron (whose finger slipped on the key that day) AC7AC



-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Darwin, Keith
Sent: Saturday, December 23, 2006 1:10 PM
To: [hidden email]
Subject: RE: [Elecraft] KPA100 Final Transistor base resistance


Maybe.  When I did my Rev D KPA100 a few weeks ago, only ONE of the
resistances was changed to read 11 - 16 in the errata.  The other still said
12 - 16.  Maybe the errata has been update in the last few weeks?
 
In my case, both transistors measured 11.5 ohms and the rig works fine.
 
73!
 
- Keith N1AS -
- K2 5411.ssb.100 -

________________________________

From: [hidden email] on behalf of Don Wilhelm
Sent: Sat 12/23/2006 12:25 PM
To: Kevin Schmidt; [hidden email]
Subject: RE: [Elecraft] KPA100 Final Transistor base resistance



Kevin,

You are OK - check the Rev D manual and its errata sheet and you will find
the range has been changed to 11 to 16 ohms.

73,
Don W3FPR



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