Setup:

CE 20A to dummy load
1 KHz audio input tone
scope accross the output of the phase shift network ( 90 deg shift)

Observation:

The X-Y scope display shows a very nice circle which varies in diameter with
the amplitude of the input and also varies in diameter (although less
variation) with the input frequency. The inside of the circle always looks
to be a well defined circle but the thickness of the line has some variation
around the circumference. Thin and sharp at 6:00 thru 10:00 and a little
thicker from 12:00 to 2:00.

The two signals look great in the time domain just like two sine waves out
of phase.

Question:

Is there something going on that needs correction?

K3PID
Ron H.

Ron,
Are you chasing a specific problem in your exciter or are you just
exercising your test equipment? How is your suppression and voice
quality?
It's been over 40 years since I fooled with Lissajou patterns on a
silly'scope, and that was in electronics school in the Army. But I do
recall that any stray signals, hum, or any distortion of the sine waves
will blur the image. Is your 1kc tone pure and clean? Seems the 20-A
manual calls for something a bit higher like 1225.
You're the first 20-A owner I've ever run across who was scrutinizing
the output of the PSN with a 'scope.
I always just tweaked everything for maximum sideband suppression
and let her rip.

When I built my first SSB phasing rig in 1958 (the infamous W2EWL
design), I borrowed a friends Heath AF generator and silly'scope, and
spent hours trying to get it right.I finally learned to do it by ear by
adjusting everything for minimum modulation with tone input while
listening on the station receiver.

I acquired my 20-A along with a Lakeshore VFO in 1964. It is still my
primary station exciter today. I use it to tickle the grids of a trio
of paralled 807's or the final stage of a Johnson Valiant.

John

I do the same thing! Adjust the side band suppression by listening to
the opposite side band while talking. It seems to work better than
with a tone as the 20A's have considerable hum in them which distorts
the tone ripple on the scope when you get down to low levels.
It also is easier to get the side band suppression balanced on both
side bands that way too.
If you use a tone one side band will end up with more suppression than
the other and you have to work back and forth to get it somewhat
balanced. By talking and listening it comes out better.

73
Gary K4FMX


On 29 Jan 2006 11:57:37 -0800, "Litzendraht" wrote:

Ron,
Are you chasing a specific problem in your exciter or are you just
exercising your test equipment? How is your suppression and voice
quality?
It's been over 40 years since I fooled with Lissajou patterns on a
silly'scope, and that was in electronics school in the Army. But I do
recall that any stray signals, hum, or any distortion of the sine waves
will blur the image. Is your 1kc tone pure and clean? Seems the 20-A
manual calls for something a bit higher like 1225.
You're the first 20-A owner I've ever run across who was scrutinizing
the output of the PSN with a 'scope.
I always just tweaked everything for maximum sideband suppression
and let her rip.

When I built my first SSB phasing rig in 1958 (the infamous W2EWL
design), I borrowed a friends Heath AF generator and silly'scope, and
spent hours trying to get it right.I finally learned to do it by ear by
adjusting everything for minimum modulation with tone input while
listening on the station receiver.

I acquired my 20-A along with a Lakeshore VFO in 1964. It is still my
primary station exciter today. I use it to tickle the grids of a trio
of paralled 807's or the final stage of a Johnson Valiant.

John

Gary,
That's interesting that you mention using your own voice rather than
injecting a tone for suppression adjustments. A long time ago I thought
about making a continous loop tape using my own voice with a long
"hello" for that very purpose.

This particular 20-A is factory wired and no adjustments have ever
been tweaked with exception the two audio balance pots and the driver
circuits on the upper bands. All the 9mc.RF slugs still have the little
blob of grey paint on the threads. All I've ever done to it was to
replace the cathode resistor in the VOX relay tube. It's value had
crept up and I really had to holler at the mic to get the relay to pull
in.

I use it more often than not barefoot just for fun. It's been a good
rig for the 42 years I've owned it.

John

On 29 Jan 2006 17:02:40 -0800, "Litzendraht" wrote:

Gary,
That's interesting that you mention using your own voice rather than
injecting a tone for suppression adjustments. A long time ago I thought
about making a continous loop tape using my own voice with a long
"hello" for that very purpose.

This particular 20-A is factory wired and no adjustments have ever
been tweaked with exception the two audio balance pots and the driver
circuits on the upper bands. All the 9mc.RF slugs still have the little
blob of grey paint on the threads. All I've ever done to it was to
replace the cathode resistor in the VOX relay tube. It's value had
crept up and I really had to holler at the mic to get the relay to pull
in.

I use it more often than not barefoot just for fun. It's been a good
rig for the 42 years I've owned it.

John

Hi John,
Guess we are on the same page for side band suppression adjustments!
I started out building my own phasing rig in the early 60's too. Then
got a 10B and latter a 20A. I have had several 20A's over the years.
Traded them off and a few years I would pick up another one.
The one I have now I drive a pair of 6146's (driving the grids) and
they drive a pair of GG 813's. It is a fun rig.

Over the years I have had various configurations of 1625's in GG that
I used with the 20A as I am sure you have too.

I have a lakeshore vfo too that I need to put on sometime. Picked it
up a few years ago and never hooked it up.
I use the 458 vfo. I was lucky enough to find the 10 meter kit for the
vfo so have that in it too. Although the crystal in the converter
drifts quite a bit. It runs off of unregulated voltage. I need to find
a way to regulate the oscillator some day.

If you haven't done so on your 20A, there was a recommended
modification to put a resistor in series with the relay coil so if the
control tube shorted it would not burn out the relay. That has
happened to several rigs.

73
Gary K4FMX

I assume you mean the audio phase shift net...

This suggests another signal getting in that is somehow affected by the
audio voltage level.

What you describe could be related to the scope astig adjustment.
or
How about RF in the scope. Kill the RF somehow.
Or power suppkly hum.
73, Steve, K,9.D.;C'I


"Ron H" wrote in message
...
Setup:

CE 20A to dummy load
1 KHz audio input tone
scope accross the output of the phase shift network ( 90 deg shift)

Observation:

The X-Y scope display shows a very nice circle which varies in diameter
with
the amplitude of the input and also varies in diameter (although less
variation) with the input frequency. The inside of the circle always looks
to be a well defined circle but the thickness of the line has some
variation
around the circumference. Thin and sharp at 6:00 thru 10:00 and a little
thicker from 12:00 to 2:00.

The two signals look great in the time domain just like two sine waves out
of phase.

Question:

Is there something going on that needs correction?

K3PID
Ron H.

I'm glad to see there's a pool of Central Electronic
phasing SSB equipment on tap here. I have a Sideband
Slicer that will be mated to an SX-28--
when I get around to restoring the pair.

I'm sure some alignment questions will arise.

Pete

Gary,

I thought I was clever using my voice instead of a tone! Hey you beat me
to it. I figured it would be like a sort of sweep generator for audio. I
make a nice long tape of cq cq cq from wa6lzh helooooo and twek it down
to wear I can barely hear the opposite sb. HT-37 never gets a bod report
now if I can slow that drift down a bit.


73 Tony WA6LZH


BTW The Heat Sideband Adapter (Outboard phasing w band switching) Manual
has an excellent explanation of the phasing method and adjustment
techniques.




Gary Schafer wrote:
I do the same thing! Adjust the side band suppression by listening to
the opposite side band while talking. It seems to work better than
with a tone as the 20A's have considerable hum in them which distorts
the tone ripple on the scope when you get down to low levels.
It also is easier to get the side band suppression balanced on both
side bands that way too.
If you use a tone one side band will end up with more suppression than
the other and you have to work back and forth to get it somewhat
balanced. By talking and listening it comes out better.

73
Gary K4FMX


On 29 Jan 2006 11:57:37 -0800, "Litzendraht" wrote:

Ron,
Are you chasing a specific problem in your exciter or are you just
exercising your test equipment? How is your suppression and voice
quality?
It's been over 40 years since I fooled with Lissajou patterns on a
silly'scope, and that was in electronics school in the Army. But I do
recall that any stray signals, hum, or any distortion of the sine waves
will blur the image. Is your 1kc tone pure and clean? Seems the 20-A
manual calls for something a bit higher like 1225.
You're the first 20-A owner I've ever run across who was scrutinizing
the output of the PSN with a 'scope.
I always just tweaked everything for maximum sideband suppression
and let her rip.

When I built my first SSB phasing rig in 1958 (the infamous W2EWL
design), I borrowed a friends Heath AF generator and silly'scope, and
spent hours trying to get it right.I finally learned to do it by ear by
adjusting everything for minimum modulation with tone input while
listening on the station receiver.

I acquired my 20-A along with a Lakeshore VFO in 1964. It is still my
primary station exciter today. I use it to tickle the grids of a trio
of paralled 807's or the final stage of a Johnson Valiant.

John