Hi Jeff,
I'll bet those KW-1s are the ones that ran the QCWA net off from 3892.
We just couldn't get through with the net when these guys come on.
JE>some nights around 3.87 to 3.89 MHz - as well as down
JE>around 3.845(+/-)MHz.
JE>Other places to hear AM are on 40m - 7.160 and 7.29MHz
JE>I've got an AM rig that I need to get going again - a pair
JE>of 250TH's modulated by a pair of 450TL's.
Holy Cow! 450TLs in the modulator? You are talking serious AM, friend. I
hope there is enough iron in the transformer for that. 
JE>Better audio can be acomplished, as well, by shunting the
JE>DC off of the secondary of the mod xfrmr.
Definitely. It also reduces the strain on the insulation and core
saturation. But cost wise adds an expensive part to the bill of
materials.
JE>With a little help from Passive Filters, full audio can be
JE>realized while on-frequency, but the filters take out the
JE>splatter up/down the band.
The spatter comes from two sources which if allowed for eliminate the
need for filters of any kind. 1. Negative peak over modulation driving
the RF finals beyond cut off. 2. Modulation transformer core saturation
on modulation peaks. Unless you have BC station assymetrical speech
processing to get over 100% positive peaks and never more than 95%
negatives you'll have to watch that max. mod. level. Lucky for you the
finals are triodes otherwise you'd need to inject some audio in the
screens also to get linear 100% mod.
Actually my favorite AM mod. process is Heising. If it was a single band
rig like for 75 meters I'd go with a Doherty.
JE>Class C has always been my favorite amplifier, whether
JE>operating CW, AM or FM.  SSB, in my opinion just sounds too
JE>nasal-y.
I developed a system (patented) back in 1956 that you'd enjoy. It is
found in a few commercial AM BC rigs. There is a carrier only final
feeding an RF combiner. On the other side is a double sideband RF final
feeding the combiner. The result is AM without splatter, beautiful hi-fi
audio out to 5kc (by law), 100% constant modulation giving the BCer that
"powerhouse sound", and a cheap rig and cheap power consumption. The
Crosley Corp. has been playing with this system and now has compatible
stereo AM on the air on many BC stations. This uses independent sideband
modulation. One sideband is the left channel, the other is the right, If
you have a modern car radio like I do you can tune in my local 600Kc
outlet in stereo. Unfortunately the house radios are FM (haha). On a
standard AM radio there is no difference in the signal. Personally, I
think AM stereo is a dumb idea but makes money so why knock it.
73,
Dick
 * SLMR 2.1a * Vultures only fly with carrion luggage.
--- Maximus/2 2.01wb
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