[AMRadio] Old Ham, New AM Enthusiast

[rbethman]

I have to second EVERY bit that Rob has posted.

I use an Amp Supply LK-500Z.  It is an "over-built" tank!

I do NOT have to dial it back.  The 20 - 25 or 40 watts from either a 
Kenwood TS0930SAT or the output from a Heathkit DX-60, (Controlled 
Carrier), have never caused the amp to have to be cooled down by backing 
off.

I also happen to own a couple of the "Tall Ships" that are plate 
modulated at the edge of legal.  I have to keep them throttled.  An 
oscilloscope or a purpose built station monitor is a MUST.

I have both - fortunately.

It takes time and patience to build up and run an AM station AND run one 
well!

Brian, W5AMI, Jim Wilhite, Bob Peters, and a host of others will lead 
you down the right path!

Look for you on the bands!

Bob - N0DGN

On 12/27/2010 1:43 PM, Rob Atkinson wrote:
> Driving an amp may be okay at first but after a while it might get
> boring.  Most AMers shoot for some kind of plate modulated rig
> eventually, but using the Icom as an exciter for an amp can be a great
> start.  The one thing you have to be mindful of is most modern
> commercially built amps are not made for AM; they are pretty much SSB
> CW amps.  Some are better than others, for example the old Henrys and
> Alphas.  To get a decent carrier to make one worth your while, you
> need at minimum a 1.2 or 1.5 KW amp; not one of those 600 w. jobs.
> You need tubes that altogether dissipate at least 1 KW, a plate v.
> supply that can handle at least 1/2 A CCS current and a lot of cooling
> through the RF deck and plate supply; not your typical quiet amp
> cooling (low air volume which is okay for SSB).   Then you can drive
> the amp to 250 or 300 w. carrier for 10 or 20 minutes and not have to
> watch it constantly while you are transmitting.  I've worked guys
> driving single 3-500 and they say they are running 300, one guy even
> claimed 400 watts.  His transmissions were very very brief hi hi.
> That's no fun.  If you go looking for an amp look for power out spec's
> for some kind of continuous duty mode like RTTY and find out if there
> is any time limit.  If for example you find a "legal limit" amp but
> the mfr says for RTTY you have to drop the power out down to 800 w.
> for no more than 10 minutes that's a tip off that something, maybe the
> cooling, is going to have to be beefed up for AM.  A FWB rectifier
> instead of a voltage doubler in the power supply is good to look for
> too.
>
> 73
>
> Rob
> K5UJ
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|               AM Amateur Radio Operator    NØDGN                 |
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