WANTED: 1KW Modulation Reactor
 

Hi,

Just finishing up my big AM rig and I'm looking for a 30 to 50 Henry at 500
mA or more modulation reactor to complete it. I'd like to locate a reactor
from a 1 KW AM broadcast rig. Decent reward for the right one.

Thanks!

Chuck...K1KW

WANTED: 1KW Modulation Reactor
 

Chuck - K1KW wrote:

Hi,

Just finishing up my big AM rig and I'm looking for a 30 to 50 Henry at 500
mA or more modulation reactor to complete it. I'd like to locate a reactor
from a 1 KW AM broadcast rig. Decent reward for the right one.

Thanks!

Chuck...K1KW


What, pray tell, is a modulation 'Reactor'?

I know what a modulation transformer is.

I know what screen grid modulation is.

I know what Heising modulation is.

But ... ???

WANTED: 1KW Modulation Reactor
 

Deek wrote:

What, pray tell, is a modulation 'Reactor'?

I know what a modulation transformer is.

Ok

I know what screen grid modulation is.

OK

I know what Heising modulation is.

I don't think so... since a modulation reactor is the "heart" of both
Heising and modified Heising modulation schemes...

kindest 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

WANTED: 1KW Modulation Reactor
 

Randy or Sherry Guttery wrote:

Deek wrote:

What, pray tell, is a modulation 'Reactor'?

I know what a modulation transformer is.


Ok

I know what screen grid modulation is.


OK

I know what Heising modulation is.


I don't think so... since a modulation reactor is the "heart" of both
Heising and modified Heising modulation schemes...

kindest regards...

Heising is inefficient shunt modulation.

WANTED: 1KW Modulation Reactor
 

Deek wrote:

Heising is inefficient shunt modulation.

Very good, now you've learned what Heising modulation is and how it's
done (what components are used, etc.). Yes, Heising is inefficient, but
it has two huge pluses as well: 1) it can be "added" to almost any
transmitter with little modification (which can then be easily removed);
and 2) it can provide excellent fidelity. So while it may be
inefficient - it remains a very popular way to add AM to transmitters.

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

WANTED: 1KW Modulation Reactor
 

Deek wrote:

What, pray tell, is a modulation 'Reactor'?

I know what a modulation transformer is.

I know what screen grid modulation is.

I know what Heising modulation is.

snip
Hi,

A modulation reactor is a big, HV insulated audio choke used to feed
d.c. to the tube finals of a broadcast a.m. transmitter.
The modulation transformer itself is capacitively coupled
across the modulation reactor. This keeps
d.c. off the modulation transformer secondary windings,
to reduce risk of saturation.

73,
Ed Knobloch

WANTED: 1KW Modulation Reactor
 

On Jun 28, 3:47 pm, "Chuck - K1KW" wrote:
Hi,

Just finishing up my big AM rig and I'm looking for a 30 to 50 Henry at 500
mA or more modulation reactor to complete it. I'd like to locate a reactor
from a 1 KW AM broadcast rig. Decent reward for the right one.

Thanks!

Chuck...K1KW

Hi,

I'm parting out a Johnson Desk Kilowatt amplifier. Would the
modulation transformer from this unit work for you?


Thanks

Wayne kd7rur

WANTED: 1KW Modulation Reactor
 

Hi,

Thanks for the offer, but it won't work for me. I'm looking for what is
basically a choke with high inductance and specially wound for this
application with 30 to 50 H for the classic modified Heising set up in my
new rig as used in many AM broadcast transmitters.

73,
Chuck...


wrote in message
ps.com...
On Jun 28, 3:47 pm, "Chuck - K1KW" wrote:
Hi,

Just finishing up my big AM rig and I'm looking for a 30 to 50 Henry at
500
mA or more modulation reactor to complete it. I'd like to locate a
reactor
from a 1 KW AM broadcast rig. Decent reward for the right one.

Thanks!

Chuck...K1KW

Hi,

I'm parting out a Johnson Desk Kilowatt amplifier. Would the
modulation transformer from this unit work for you?


Thanks

Wayne kd7rur

WANTED: 1KW Modulation Reactor
 

Randy or Sherry Guttery wrote:
Deek wrote:

Heising is inefficient shunt modulation.


Very good, now you've learned what Heising modulation is and how it's
done (what components are used, etc.). Yes, Heising is inefficient, but
it has two huge pluses as well: 1) it can be "added" to almost any
transmitter with little modification (which can then be easily removed);
and 2) it can provide excellent fidelity. So while it may be
inefficient - it remains a very popular way to add AM to transmitters.

best regards...

I learned what Heising Modulation was back in the early 50s while earning an EE
degree. Your sarcasm is misplaced.

WANTED: 1KW Modulation Reactor
 

Edward Knobloch wrote:

SNIPPED
Hi,

A modulation reactor is a big, HV insulated audio choke used to feed
d.c. to the tube finals of a broadcast a.m. transmitter.
The modulation transformer itself is capacitively coupled
across the modulation reactor. This keeps
d.c. off the modulation transformer secondary windings,
to reduce risk of saturation.

73,
Ed Knobloch

THANKS

WANTED: 1KW Modulation Reactor
 

Chuck - K1KW wrote:
Hi,

Just finishing up my big AM rig and I'm looking for a 30 to 50 Henry at
500
mA or more modulation reactor to complete it. I'd like to locate a
reactor
from a 1 KW AM broadcast rig. Decent reward for the right one.

Thanks!

Chuck...K1KW

Chuck,
Have you tried Peter W. Dahl Company (http://www.pwdahl.com/)? It appears
they make chokes.
73,
Bryan WA7PRC

WANTED: 1KW Modulation Reactor
 

Chuck - K1KW wrote:

Thanks for the offer, but it won't work for me. I'm looking for what is
basically a choke with high inductance and specially wound for this
application with 30 to 50 H for the classic modified Heising set up in my
new rig as used in many AM broadcast transmitters.

Hmm... and it's got to be nice and broadband. How much DC is going
through there?

I assume the secondary winding off a microwave oven transformer isn't going
to be more than ten henries or so.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

WANTED: 1KW Modulation Reactor
 

Bryan wrote:

Chuck,
Have you tried Peter W. Dahl Company (http://www.pwdahl.com/)? It appears
they make chokes.

They make wonderful chokes for all kinds of broadcast applications, they
have the best customer service I have ever seen, and the do beautiful work.

But they charge a fair price for their work, and that's often more than
I'd be willing to pay for a ham rig...
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

WANTED: 1KW Modulation Reactor
 

Deek wrote:

I learned what Heising Modulation was back in the early 50s while
earning an EE degree. Your sarcasm is misplaced.

Obviously, then, you forgot how Heising Modulation worked, or you
wouldn't have asked the question; and (hopeful) you've re-learned / been
reminded - how Heising Modulation works, specifically the use of a
modulation reactor as specified by the OP; - no sarcasm intended.

To "pick a nit" - Mr. Knobloch's description is only partially correct -
in that his description is of a *modified* Heising modulator. A
saturable reactor can also be used in a circuit without "capacitively
coupling an output of a modulation transformer" (i.e. no modulation
transformer at all) - which is a basic / original Heising modulator (as
opposed to a modified Heising).

early 50s: That is a long time. I've carried an FCC 1st since 66
- (when I was 16) added RADAR endorsement in 78. Still have my license
hanging on one last commercial AM broadcast transmitter, though I'd like
to retire from that one as well (at one time I had over a dozen AM&FM
stations here under my license).

You can see the last "tantrum" that transmitter threw he

http://www.comcents.com/rg/mw5.html

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

WANTED: 1KW Modulation Reactor
 

"Randy or Sherry Guttery" wrote in message
. ..
Deek wrote:

I early 50s: That is a long time. I've carried an FCC 1st since
66
- (when I was 16) added RADAR endorsement in 78. Still have my license
hanging on one last commercial AM broadcast transmitter, though I'd like
to retire from that one as well (at one time I had over a dozen AM&FM
stations here under my license).

--
randy guttery

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

Small world! I got my 1st back in either 65 or 66 in high school. Working
transmitter summer relief was a lot better than picking tobacco with the
other high school kids back then.

Pete

WANTED: 1KW Modulation Reactor
 

Uncle Peter wrote:

Small world! I got my 1st back in either 65 or 66 in high school. Working
transmitter summer relief was a lot better than picking tobacco with the
other high school kids back then.


Hey Pete!

Yes, indeed... it also allowed a "wet behind the ears" kid to hang
around a radio station and meet some interesting characters. In my
case - helping to move a studio from the basement of a church to more
"suitable" digs... and getting to meet some of the deejays... I'll
never forget sitting on the board riding the gain while Dr. Demento cut
loose with a visitor: if you ever heard the Wolfman's howl live - you'd
never ever forget it!!!

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

WANTED: 1KW Modulation Reactor
 

Yes, that is my last choice due to their price for one.
Chuck...


"Bryan" wrote in message
...
Chuck - K1KW wrote:
Hi,

Just finishing up my big AM rig and I'm looking for a 30 to 50 Henry at
500
mA or more modulation reactor to complete it. I'd like to locate a
reactor
from a 1 KW AM broadcast rig. Decent reward for the right one.

Thanks!

Chuck...K1KW

Chuck,
Have you tried Peter W. Dahl Company (http://www.pwdahl.com/)? It appears
they make chokes.
73,
Bryan WA7PRC