Howard pretty well summarized it Richard.  After dark, ten meters is, 
as a rule void of signals.  The same is likely for fifteen meters, 
but not necessarily always the case.  But if the band is "dead", all 
forms of signal, C W, SSB, F M and AM will all be gone.
Hope this helps.
pat At 08:25 AM 11/23/2014, you wrote:
>Hi Pat!
>
>Thanks for your below.  I really appreciate you telling me where (what
>bands) and when (night) to troll around to hear AM transmissions!  As a
>furtherance of this, indeed I notice that the 10M band seems to "close" for
>me at night; at least where I live in Los Angeles and in USB.  Might what
>you say below mean that transmissions on this band in the evening would be
>better in AM rather than USB?
>
>73,
>Richard KK6MRH
>
>-----Original Message-----
>From: For blind ham radio operators [mailto:[log in to unmask]]
>On Behalf Of Pat Byrne
>Sent: Saturday, November 22, 2014 10:17 AM
>To: [log in to unmask]
>Subject: Re: A Primer on the AM Mode
>
>Richard,
>A M is the way we used to comminicate via voice on the ham bands, likely
>long before you were born!  Not to begin a long, old fart rave about the
>mode, but it was the way that things were in the late fifties when I got
>licensed.  However, single sideband was coming along then and eventually A M
>lost favor.  The cons are that it takes up at least double the bandwidth of
>a voice comunication using both sidebands.  And, watt for watt it takes more
>power than an equivalent sideband transmission.  And a good A M transmitter
>requires a lot more engineering than its sideband equivalent.  I'll back
>away from that a bit and say different engineering and equipment.
>The big pro is the possible great sound of A M.  If you listen around
>seventy-five and forty meters, probably more night time than day, with your
>receiver set to A M, you may hear some really good sounding transmisions.
>There are a few hams still enjoying the mode a lot.  When ten is open, the
>frequencies just above 29 mhz. might have some A M transmissions around.
>And it is a mix of old, fifties and earlier equipment and the newer
>transceivers that you will hear.
>I could go on a lot longer but this should give you the idea.  Occasionally
>listen on ten meters and try the other lower frequency bands after dark and
>find out what there is to hear.
>Hope this helps.
>Pat, K9JAU who started on A M and still loves the memories.At 10:41 AM
>11/22/2014, you wrote:
> >Hi!
> >
> >
> >
> >As a new ham, I am curious about the AM mode.  I would like to learn a
> >bit more about it.  I think I basically understand the USB, LSB and FM
> >modes, but the AM mode is a mystery to me.
> >
> >
> >
> >When, where and why does one use AM?  What are the pros/cons of it?
> >Can you direct me to some reading about its use?
> >
> >
> >
> >73,
> >
> >Richard KK6MRH