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[Amps] Fw: 8877 amp

To: "AMPS" <>
Subject: [Amps] Fw: 8877 amp
From: "Jim W7RY" <>
Reply-to: Jim W7RY <>
Date: Tue, 17 Nov 2015 20:52:39 -0800
List-post: <">>

Thanks Jeff...

The displays are simply cheap (EBay specials from China) digital voltmeters
without decimal places. The pots are 10 turn linear taper and geared down to
1:3 So 3 turns on the cap is one turn on the pot. So just a simple voltage
divider. I do use regulated voltage so the readings don’t change under load.
I supply the meters with adjustable voltage so I can set the intensity of
the displays. With a full 5 volts, they are just too bright. So I run around
3 volts to them

The plastic gears and chain are from Small Parts. Cheap and easy to use.
I did make the L brackets so they are adjustable so I can change the tension
on the plastic chain. This keeps the backlash to a minimum so the
repeatability is better.

The setup is very repeatable so tuning is a snap even during contests which
is 99.9% of my operating.

Jim W7RY

-----Original Message----- From: Jeff Pederson
Sent: Monday, November 16, 2015 9:36 AM
Subject: 8877 amp

Im working on an 8877 amp 80-10 meters. Very nice work. Where did you get
the digital turns counters and pots? I tried looking on ebay and google
without much success.


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