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Re: [Amps] 6 meter 8877 amplifier

To: "Bill Turner" <dezrat1242@yahoo.com>
Subject: Re: [Amps] 6 meter 8877 amplifier
From: "Jim W7RY" <w7ry@centurytel.net>
Reply-to: Jim W7RY <w7ry@centurytel.net>
Date: Thu, 13 Dec 2012 06:53:43 -0800
List-post: <amps@contesting.com">mailto:amps@contesting.com>
You're right Bill. But it's poorly written./
73
Jim W7RY


2. You do not need an input matching circuit. The 8877 input impedance is very close to 50 ohms anyway. If you insist on a perfect match, the antenna tuner in
your transceiver can do the job.

3. You do however, need a parallel resonant tank in the input circuit to provide the 'flywheel' effect. I used a Q of five. This requires a 9-position switch for the input and a means of tuning each band. I used individual toroids and mica compression trimmers. Do not try to 'tap' a toroid. Use 9 individual toroids.




-----Original Message----- From: Bill Turner
Sent: Wednesday, December 12, 2012 9:52 PM
To: Jim W7RY
Cc: Amps
Subject: Re: [Amps] 6 meter 8877 amplifier

ORIGINAL MESSAGE:
On Wed, 12 Dec 2012 21:32:10 -0800, W7RYwrote:

What a huge misconception! We have discussed this since the cows started to
come home! You NEED a tuned input.


73
Jim W7RY

REPLY:
I'm afraid the misconception is on your part, Jim. I NEVER said you
don't need a tuned input circuit. I said you don't need an IMPEDANCE
MATCHING circuit for the 8877. You do need a parallel resonant tank
circuit in the input for the "flywheel" effect, but that has nothing
to do with impedance matching.

Please read my ENTIRE post again.

73, Bill W6WRT
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