Is that into an antenna or a known 50 Ohm dummy load?
As long as it tunes from 3.5 to 4.0 I wouldnt worry. The tuning point is
fixed by the LC of the tank circuit.
Carl
KM1H
----- Original Message -----
From: "Joe Frank" <jfrank002@neo.rr.com>
To: <amps@contesting.com>
Sent: Wednesday, August 27, 2008 2:01 PM
Subject: [Amps] SB-1000
> Built my SB 1000 about 10 to 12 years ago but was travelling a lot and
> used ALS 500 in motor home so SB 1000 has had little use.
>
> Initial start up was normal except for one quirk. Resonant point for
> plate variable capacitor is WAY OFF on the dial as compared to 80
> meter dial mark. At 3875 instead of pointing at the 80 meter mark
> (maybe 80% meshed) it resonates near the center of the dial ( maybe
> 30% meshed) just to the left of the 40 meter point.
>
> Have double checked construction details many times and have given up
> on finding the problem.
> Doorknob caps---labeled value in proper place and connected to band
> switch as instructed. Also checked all details of connection of coil
> L-8.
> Control knob and pointer are attached and oriented to the capacitor
> position as instructed.
>
> The 40, 20, 15 & 10 meter circuits are normal with normal pointer
> position.
>
> The amp works OK and serves my needs as is but I am not comfortable
> with it since it is not normal operation and I would not want to sell
> it in this condition.
>
> Could you speculate as to possible cause of this problem. My first
> guess was too much fixed capacity in the circuit but I have no
> equipment to measure the actual value of the doorknobs. Have
> considered replacement in case they are mislabeled. Would sure
> appreciate any comments you could make about this problem.
> Thank You
> Joe M Frank WA8JOE
> jfrank002@neo.rr.com
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>
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