[AMPS] ALC question

[rdl2@igs.net]

Rich (and all others who care to comment):

I'm a neophyte to the RF PA world (and this group) and after almost 30
years of operating, I only acquired my first amp about a week ago...a
previously loved AL80A (single 3-500Z), so please bear with me if these are
dumb questions.

I, too, was wondering about Jeff, K4JNY's question about whether or not to
leave the amp running. After reading Rich's referenced January 1994 QST
article, "The Nearly Perfect Amplifier" I'm not sure if I know the answer
although I think the step-start circuit would be kinder to the tube
elements.

However, towards the end of Rich's article, another issue arose which has
been perplexing me:

Do you need to connect the ALC line between the amplifier and the transceiver?

The vendor of my used amp said he never used it...he just made sure he was
within the ALC on his transceiver. Others have told me that they wou ld
never use an amp without the ALC connection.

In his article, Rich says: "Amplifier-to-transceiver ALC only works
properly on modes with a constant signal level, such as RTTY and FM." Rich
seems to favor a 25-ohm cathode feedback resistor in series with the
cathode coupling capacitor as more desirable than ALC and its "generic flaw
(of) leading-edge splatter on SSB."

Any advice/suggestions on the ALC connection question would be most welcome
before I fire the thing up.

Thanks and 73,
Rob, VE3YE

----------------------------------------------------------
Robin Ludlow, VE3YE, Editor, The Canadian Amateur
1010 Bosque Crescent, Cumberland, ON, CANADA  K4C 1C3
Phone: 613-833-2766                           Fax: 613-833-2716
E-mail: RDL2@igs.net      Packet radio: VE3YE@VE3KYT
Radio Amateurs of Canada web site:  http://www.rac.ca
-----------------------------------------------------------



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