AM operation of KWM?
 

I saw an auction for a Sampson Modulator which looks to be a way to
apply full plate modulated audio to the output section of a Collins
transmitter or transceiver. it has the "11 pin octal" socket which is
used, aside from relays, only two places I know of, the Collins S-Line
ham equipment and Hammond organ speaker cabs.

First, is that what this is?

Second, since the KWM-2 has no AM position, how is the BFO disabled
for AM rx operation? The audio would be unpleasant even if intelligible
if AM were listened to in a SSB mode.


My guess is that this was actually intended for illicit 11 meter use
but would be usable on any band.

Actually, receiving am with a bfo is fine. You are just copying 1/2 of the
sideband. The Drake 1A came out when am was still popular and no am
detector or switch. Called exhalted carrier or something like that.

I think there were a number of rigs that use the 11 pin plug. The Johnson
products, including the Ranger and Pacemaker and Valiant, if I recall
correctly. But, do not shoot me, please, if I am wrong. My wife points out
my faults often.

73, Colin K7FM

"Bret Ludwig" wrote in message
oups.com...

I saw an auction for a Sampson Modulator which looks to be a way to
apply full plate modulated audio to the output section of a Collins
transmitter or transceiver. it has the "11 pin octal" socket which is
used, aside from relays, only two places I know of, the Collins S-Line
ham equipment and Hammond organ speaker cabs.

First, is that what this is?

Second, since the KWM-2 has no AM position, how is the BFO disabled
for AM rx operation? The audio would be unpleasant even if intelligible
if AM were listened to in a SSB mode.


My guess is that this was actually intended for illicit 11 meter use
but would be usable on any band.


11 pin Octal socket was used on a LOT of equipment in the 50/60s.

Your right tho....sounds like some sort of CB junk to me.

I used Collins S-lines and KWM2s for years. Never ever heard of a outboard
"AM Modulator". Why anyone would want to do that is beyond me.

Dan/W4NTI

Behold, Dan/W4NTI scribed on tube chassis:


"Bret Ludwig" wrote in message
oups.com...

I saw an auction for a Sampson Modulator which looks to be a way to
apply full plate modulated audio to the output section of a Collins
transmitter or transceiver. it has the "11 pin octal" socket which is
used, aside from relays, only two places I know of, the Collins S-Line
ham equipment and Hammond organ speaker cabs.

First, is that what this is?

Second, since the KWM-2 has no AM position, how is the BFO disabled for
AM rx operation? The audio would be unpleasant even if intelligible if
AM were listened to in a SSB mode.


My guess is that this was actually intended for illicit 11 meter use
but would be usable on any band.


11 pin Octal socket was used on a LOT of equipment in the 50/60s.

Your right tho....sounds like some sort of CB junk to me.

I used Collins S-lines and KWM2s for years. Never ever heard of a
outboard "AM Modulator". Why anyone would want to do that is beyond me.

Dan/W4NTI

Looking at my 1963 ARRL Radio Amateur's Handbook, outboard modulators
were the "in" thing back then.

--
Gregg "t3h g33k"
http://geek.scorpiorising.ca
*Ratings are for transistors, tubes have guidelines*

Gregg wrote:




11 pin Octal socket was used on a LOT of equipment in the 50/60s.

Your right tho....sounds like some sort of CB junk to me.

I used Collins S-lines and KWM2s for years. Never ever heard of a
outboard "AM Modulator". Why anyone would want to do that is beyond me.

Dan/W4NTI


Looking at my 1963 ARRL Radio Amateur's Handbook, outboard modulators
were the "in" thing back then.


Not on SSB rigs.
-Bill

-ex- wrote:
Gregg wrote:

snip
Dan/W4NTI


Looking at my 1963 ARRL Radio Amateur's Handbook, outboard modulators
were the "in" thing back then.


Not on SSB rigs.
-Bill


That's the point. If you HAD a KWM and wanted to work AM, apparently
this was the thing.

Bret Ludwig wrote:
-ex- wrote:

Gregg wrote:


snip

Dan/W4NTI


Looking at my 1963 ARRL Radio Amateur's Handbook, outboard modulators
were the "in" thing back then.


Not on SSB rigs.
-Bill



That's the point. If you HAD a KWM and wanted to work AM, apparently
this was the thing.


Uh...I was referring to the 1963 Handbook comment.

-Bill

By 1963, AM was called "Ancient Mary" in ham circles, which is why
Collins didn't provide for it. 11 meters was and is a different story.
It is of course illegal to operate a S-Line or any other
non-type-certified CB transmitter on that band, which makes the
practice all the more fun for the dedicated "Chicken Bandit".

-ex- ) writes:
Bret Ludwig wrote:
-ex- wrote:

Gregg wrote:


snip

Dan/W4NTI


Looking at my 1963 ARRL Radio Amateur's Handbook, outboard modulators
were the "in" thing back then.


Not on SSB rigs.
-Bill



That's the point. If you HAD a KWM and wanted to work AM, apparently
this was the thing.


Uh...I was referring to the 1963 Handbook comment.

-Bill

Obviously, if you wanted AM on an SSB rig, you'd have little choice
but to add an external plate modulator (unless you unbalanced the balanced
modulator(s) and bypassed the crystal filter if it was a filter rig).

But yes, external modulators seemed common at that time, and maybe
for a longer period. When the US Novice license came along, it made
a certain amount of sense to have the modulator external, so the rig
was initially cheaper and you didn't need a modulator until you upgraded
your license.

An external modulator was also a way of dividing the weight. Get the
heavy modulation transformer out of the main rig.

But from reading of material from that period, nobody seemed to be
plate modulating an SSB rig.

Michael VE2BVW

Bret Ludwig wrote:

By 1963, AM was called "Ancient Mary" in ham circles, which is why
Collins didn't provide for it. 11 meters was and is a different story.
It is of course illegal to operate a S-Line or any other
non-type-certified CB transmitter on that band, which makes the
practice all the more fun for the dedicated "Chicken Bandit".


Ok.

-Bill