[AMRadio] HAMCOM 2011

[Rob Atkinson]

Hi Bernie,

It is not quite that simple.   Most modern consumer grade RF linear
amps sold to hams are not really built for AM and new hams and even
some long time hams who have spent their time operating SSB may not
realize that.  I remember I worked some guy down south last year
running a single 3-500 amp and said he had a 400 watt carrier.  Not
good obviously.  I explained the parameters to him and that he should
probably hold his carrier power to at most 200 w., preferably more
like 175 with that tube and the under rated h.v. supply in the amp and
he took off.  Never  even came back to me after the QSO had begun.   A
forum might be a better way to communicate to folks.   The big high
dollar amps may be more bullet proof but the SB200/AL80/AL811 etc.
type amps are not.    Besides cutting costs, manufacturers make them
quiet i.e. not a lot of cooling.  Okay for SSB but not real good for
AM if they try to make a buzzard 10 minute transmission.

Anyway, it was just an idea since forum topic suggestions were asked
for; I won't be there so if you all want to hash over something else
FB with me hi hi.

73

Rob
K5UJ

On Wed, Apr 13, 2011 at 2:30 PM, Bernie Doran
<qedconsultants at embarqmail.com> wrote:
> I  fail to understand what the big deal is with a linear amp on AM,  if you
> can figure out how to run it on SSB you are basically done. Tune it the same
> way with carrier, then reduce the drive to the point where the output power
> is about 20 %. Thats pretty much it!! just make sure that the input does not
> exceed the plate disipation rating of the tubes and that they really do have
> enought air on them.  Now if you do not know how to tune it for linear op on
> SSb, that is a different problem.
>  Original Message -----
> From: "Phil Townsend" <philji at mac.com>
> To: "Discussion of AM Radio in the Amateur Service"
> <amradio at mailman.qth.net>
> Sent: Wednesday, April 13, 2011 2:59 PM
> Subject: Re: [AMRadio] HAMCOM 2011
>