Ok, the Modern Amp seems to be the way to go with an old AM xmtr, mainly
because they have 160 mtrs (THE band where higher power is almost
necessary)and also I can call a 800 number and get one fast.

Which amp is best for my circumstance?

I have a Ranger running 40 watts AM for drive.I want legal limit AM or
close to it with a modern Amp that can take it and not burn up because
of the duty cycle. Suggestions under $2500 new price please.

Which amp tube would be best for AM - 572's - 811's - 3-500's or the
high gain ceramic tubes?

Thanx

Lazy Senior

Lazy Senior ) writes:
Ok, the Modern Amp seems to be the way to go with an old AM xmtr, mainly
because they have 160 mtrs (THE band where higher power is almost
necessary)and also I can call a 800 number and get one fast.

No, and I don't know where you got that.

Nobody used a linear amplifier for AM in amateur radio circles.
They either used medium power to start with, or went with a full kilowatt
amplifier with suitable modulator. They made sure they had the space,
and made sure the floor was strong enough.

If your transmitter isn't powerful enough for you, then you find a more
powerful AM transmitter. If that's still not enough, then you build
or buy a full power amplifier or transmitter.

You won't get much power out of a linear amplifier because of
the way things work.

Just because nobody makes a kilowatt AM transmitter these days, and
you aren't interested in building one, does not mean a linear amplifier
is "the way to go".

Michael VE2BVW

Which amp is best for my circumstance?

I have a Ranger running 40 watts AM for drive.I want legal limit AM or
close to it with a modern Amp that can take it and not burn up because
of the duty cycle. Suggestions under $2500 new price please.

Which amp tube would be best for AM - 572's - 811's - 3-500's or the
high gain ceramic tubes?

Thanx

Lazy Senior

Michael Black wrote:


Nobody used a linear amplifier for AM in amateur radio circles.
They either used medium power to start with, or went with a full kilowatt
amplifier with suitable modulator. They made sure they had the space,
and made sure the floor was strong enough.


You must not work AM. I talk daily on AM (with my Valiant)and find hams
running linear amps at legal limit. They ALL sound good. Most are
driving the amp with old xmtrs....

Lazy Senior

Lazy Senior wrote:
Michael Black wrote:

Nobody used a linear amplifier for AM in amateur radio circles.
They either used medium power to start with, or went with a full kilowatt
amplifier with suitable modulator. They made sure they had the space,
and made sure the floor was strong enough.

You must not work AM. I talk daily on AM (with my Valiant)and find hams
running linear amps at legal limit. They ALL sound good. Most are
driving the amp with old xmtrs....

Folks are doing that today, but in previous years it was much more common
to run the transmitter with no modulation, and run it into a (very nonlinear)
amplifier running the legal limit. Then you'd modulate the finals of the
outboard amplifier.

The good part about this is that your amplifier is now much smaller and
has lower input power than a linear amplifier that is truly linear. The
bad news is that now you need a modulation deck putting out half as
much AF power as your RF output, and a gargantuan transformer.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Lazy - Most modern amps being "linear" are not the way to go for AM as
they have poorer efficiency than the older Class C amps with high level
modulation. If you want an AM transmitter check out the ARRL handbooks
and ham ads for the 1950 to 1970s when AM was king.

Higher power on 160 is nice as the band can be noisy and the higher
power is needed to over come the noise level at the receiving end. BTW
- a way around this is to limit the receive bandwidth as with CW or
other slow speed forms of modulation and some most interesting work has
been done with very low power levels.

A problem you will find with older AM gear is that the manufactures
didn't support 160 meters years ago. The band had been taken over by
the government's LORAN A service during WWII and partly given back to
the hams with a 50 watt power lamination depending on where you lived.
Most hams didn't attempt to use 160 and this limited store bought
equipment.

If you have the room and technical ability might consider converting a
salvaged AM broadcast transmitter. They are available as most stations
are removing them to upgrade to much more efficient solid state units.

Good luck in your quest

73 Bob W7AVK

\

Lazy Senior wrote:


Ok, the Modern Amp seems to be the way to go with an old AM xmtr, mainly
because they have 160 mtrs (THE band where higher power is almost
necessary)and also I can call a 800 number and get one fast.

Which amp is best for my circumstance?

I have a Ranger running 40 watts AM for drive.I want legal limit AM or
close to it with a modern Amp that can take it and not burn up because
of the duty cycle. Suggestions under $2500 new price please.

Which amp tube would be best for AM - 572's - 811's - 3-500's or the
high gain ceramic tubes?

Thanx

Lazy Senior

Bob W7AVK wrote:


If you have the room and technical ability might consider converting a
salvaged AM broadcast transmitter. They are available as most stations
are removing them to upgrade to much more efficient solid state units.

Yup - a Harris MW1 would be ideal... save for the power transformer(s)
nearly everything else can be either hand made (coils, etc.) or bought
off the shelf (transistors, etc.- including the PAs). The "output" unit
consists of 13 identical RF modules twelve as PAs - one a driver. They
"normally" run a 83W each - if one dies - the matching network
effectively isolates it - the drive to the remaining PAs "steps up" -
and it stays at a KW. One of easiest to maintain transmitters around
(from both layout - and parts availability). PA B+ is (IIRC) something
like 70V - the modulators consist of two sections - one that passes the
70V (i.e. saturated at 0% modulation) - or ramps down towards cutoff
with negative modulation- the other section of the modulator is tied to
+140V - and as positive modulation is applied - it overrides the 70V
rail - and up it goes pulling the PAs with it. Capable of 110% positive
modulation if everything is up to snuff. Each of those 13 identical PA
modules includes it's modulator (both sections). Very efficient for an
AM transmitter.

best regards...
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com

Lazy Senior wrote:


Which amp is best for my circumstance?



Which amp tube would be best for AM - 572's - 811's - 3-500's or the
high gain ceramic tubes?

Thanx

Lazy Senior

Lazy:
People dont seem to read what you are asking - Suggestions for a modern
linear amp to be used on Am. --A simple question-- but everyone "wants"
to tell you it cant be done,shouldnt be done, or you dont need high
power,buy another xmtr, etc etc.

Yes, I Know people use Linear amps with old xmtrs, I have talked to many
of them.

Lazy Senior

Lazy Senior wrote:

Lazy:
People dont seem to read what you are asking - Suggestions for a modern
linear amp to be used on Am. --A simple question-- but everyone "wants"
to tell you it cant be done,shouldnt be done, or you dont need high
power,buy another xmtr, etc etc.

Yes, I Know people use Linear amps with old xmtrs, I have talked to many
of them.

Well, yes, but you can use ANY modern linear amp, just as long as it is
rated for full power at AM.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Lazy Senior

Lazy:
People dont seem to read what you are asking - Suggestions for a modern
linear amp to be used on Am. --A simple question-- but everyone "wants"
to tell you it cant be done,shouldnt be done, or you dont need high
power,buy another xmtr, etc etc.

Yes, I Know people use Linear amps with old xmtrs, I have talked to many
of them.

Lazy Senior



Ya know... You specifically asked what type of "linears" would have
been use back when AM the common mode. Your question was
answered. Now your starting with the backtracking BS about
a modern "amplifier."

If you "know" people who are using linears with old
xmtrs", why not just ASK THEM WHAT THEY ARE
USING and quit trolling this newsgroup
with your BS?

Peter k1zjh

Uncle Peter wrote:


If you "know" people who are using linears with old
xmtrs", why not just ASK THEM WHAT THEY ARE
USING and quit trolling this newsgroup
with your BS?

Peter k1zjh


Same old crap from usenet, its why I hardly use it for getting info. Too
many assholes like you. Self Proclaimed experts always call you a troll
when they cant supply you with usefull info.

If you think I am trolling just put me on your kill list, I wont miss you.

I asked a simple question, you just gave me bul**** answers. Most of the
really good replys I got via email.

Dont bother replying I am not looking for a flamefest....

Lazy Senior