Hi Jeff,
JE>Just where DOES one find a 40 to 50 Hy choke, at half an amp these days?
 Don't need one that big. Say 5 Henries will do the job and any more are
 excess. You will need the 0.5 A though.
JE>That's the plan, and the desire for using the 450TL's
JE>Always use around twice what you need, for that 'safe'
JE>margin.  A single 833 modulated by a PAIR of 'em works SO
JE>cooly at 500w DC Input.
I had that setup up until 1957. Also a lot of BC transmitters were the
same, suckers ran 24 hours a day 7 days a week for years before the
tubes wore out.
JE> RP> Unless you have BC station assymetrical speech processing to
JE>The EXACT reason I didn't want to go with 813's or 4-250's
JE>in the final.  While the 813 could be triode connected, it
JE>seemed more of a pain than it was worth.
I used 813 hi mu triode connected---really nice but a dog to get a pair
on 10 meters. Too high output capacity. That was a sweet rig.
JE> RP> Actually my favorite AM mod. process is Heising. If it was a
JE> RP> single band rig like for 75 meters I'd go with a Doherty.
JE>Have seen and read several articles on 'Negative Cycle
JE>Loading'.  It's like a dummy load for the negative cycle of
JE>the audio, when there's no load on the output of the mod.
JE>amp.
You get that with the Doherty and the Terman-Woodward. Both use a second
tube and RF phasing lines. The second tube sucks up the RF acting like a
resistor. Saw that set up in the old 50 KW BC transmitters. No
modulation transformer and all that expensive stuff. The cost was in
"wasted" electricity which instead of being a capital expense to set up
the station became an operating expense--so it got paid out of revenues.
It made for a 50KW ( about 5 stations I can think of had licenses for
100KW) with almost no parts in it. Foreshadowing the infamous Muntz
TV set with only 9 tubes in the era of the RCA 630 chassis with 29 tubes
plus the picture tube; thats why the -30.
JE> RP> (haha). On a standard AM radio there is no difference in the
JE> RP> signal. Personally, I think AM stereo is a dumb idea but
JE> RP> makes money so why knock it.
JE>If there was a reciever designed to copy it, it wouldn't be
JE>a bad idea to program the sidebands independatly, therefore
JE>increasing the bandwidth for broadcast stations.
JE>Maybe something like 680A and 680B, utilizing the Balance knob 
Haha, way too late!! That's been around since (circa 1955) the
Collins military/commercial 500 watt ssb rig known as the KWT-6. That
was the first independent sideband radio and some are still around.
Voice of America can be heard using it to feed programs to relay
stations. Two programs at a time. Then about 1960something it was
modified to provide 4 independent channels; two upper sideband and two
lower sideband. Total RF bandwidth determined by the bandwidth of the
inputted audio.
73,
Dick
 * SLMR 2.1a * NO CARRIER -- Navy pilot's worst nightmare!
--- Maximus/2 2.01wb
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