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Power adjustment on the TS-440S

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John Gratton

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Feb 2, 1996, 3:00:00 AM2/2/96
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We have a company station with a Kenwood TS-440S(AT).
We Recently bought a PK-232MBX and I was trying to
bring things up last night when it occured to me I don't
know how to limmit the power output of the rig.

I went through the manual and read about the 'CAR' knob,
which the manual states limits the carrier during
AM transmissions.

I could not, however, find anything that would let
me adjust the RF output while in LSB mode.
(Note, we couldn't find a 13 pin din connector
to use the aux port on the 440, so we are going
in through the mic jack).

Does anyone know if it's possible to lower the power
output of this rig? I read a paragraph that said ' when in
FSK mode a key down time of 60 minutes requires a cool
down of 30 minutes' (or words to that effect). This leads
me to believe that it is not possible to turn the thing down!

Any comments?
--
John Gratton | jo...@net.com
Hans Christian 33 "Nakia" | (415)780-5774

Floyd Adams

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Feb 3, 1996, 3:00:00 AM2/3/96
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jo...@emerald.net.com (John Gratton) wrote:

Adjusting the Mic Gain on the 440 will NOT adjust the power like other
rigs. I had a friend show me how to do it with a 9 volt battery. The
theory behind this mod is to apply a NEGATIVE voltage to pin 6 of the
7 pin Din plug on the back of the 440. This is the ALC pin, which
normally would get feed from a Linear and the greater the negative
voltage, the more the power (amp. drive) is cut back. He used a 9
volt batter and a 1k pot. He connected the pot across the 9v battery
and let the wiper feed pin 6. the + side of the battery went to the
outer connector casing. I never used the mod, but it makes sense and
should work. Good Luck and 73's

Floyd (WD5ENJ)


jlei...@planet.net

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Feb 3, 1996, 3:00:00 AM2/3/96
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> jo...@emerald.net.com (John Gratton) writes:
> We have a company station with a Kenwood TS-440S(AT).
> We Recently bought a PK-232MBX and I was trying to
> bring things up last night when it occured to me I don't
> know how to limmit the power output of the rig.
>
> I went through the manual and read about the 'CAR' knob,
> which the manual states limits the carrier during
> AM transmissions.
>
> I could not, however, find anything that would let
> me adjust the RF output while in LSB mode.
> (Note, we couldn't find a 13 pin din connector
> to use the aux port on the 440, so we are going
> in through the mic jack).
>
> Does anyone know if it's possible to lower the power
> output of this rig? I read a paragraph that said ' when in
> FSK mode a key down time of 60 minutes requires a cool
> down of 30 minutes' (or words to that effect). This leads
> me to believe that it is not possible to turn the thing down!
>
> Any comments?
> --
> John Gratton | jo...@net.com
> Hans Christian 33 "Nakia" | (415)780-5774
>
>>>>
On sideband you can lower the power by using the mic gain on the radio, and the carrier for CW, AM,FM,FSK.
If you want to internally set power lower then 100 watts on CW hit the VR pot,bottom of radio in the back.
You can set it at 50,60,80 or whereever if you wish.

Gary Coffman

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Feb 4, 1996, 3:00:00 AM2/4/96
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In article <4f0krb$k...@news-f.iadfw.net> fla...@iadfw.net (Floyd Adams) writes:
>Adjusting the Mic Gain on the 440 will NOT adjust the power like other
>rigs.


Why not, Floyd? Output power is a function of modulation level for
a SSB transmitter. If it weren't, the radio would put out as much
power when you weren't talking as when you do.

Gary
--
Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems | we break it. | emory!kd4nc!ke4zv!gary
534 Shannon Way | Guaranteed! | ga...@ke4zv.atl.ga.us
Lawrenceville, GA 30244 | |

Floyd Adams

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Feb 5, 1996, 3:00:00 AM2/5/96
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ga...@ke4zv.atl.ga.us (Gary Coffman) wrote:

Hi Gary,

We had this discussion a while back here in one of the amateur
newsgroups. The MIC Carrier works only in the AM, FM and CW modes.
In SSB it does nothing. The MIC Gain control will reduce the
transmitted audio level to the point that you cannot be heard, but it
does not reduce the power out. Power will reduce, because there is
little or no audio transmitted. The guy that gave me the mod I listed
used it to work QRP. He said that someone at Kenwood told him that it
was the only way to reduce the level. The TS-450, which replaced the
TS-440, has a PWR Control that does reduce the power out. I guess
Kenwood realized that they forgot to allow an operator to do what the
FCC requires, use the least amount of power to make your communication
path reliable. Although I have not made the mod he told me about, it
looks like it should work, since the radio will respond to the ALC
feedback it receives from an amp. I hope that helps explain it a bit.

73's

Floyd WD5ENJ


Clark Savage Turner

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Feb 5, 1996, 3:00:00 AM2/5/96
to
In <1996Feb5.1...@ke4zv.atl.ga.us> ga...@ke4zv.atl.ga.us (Gary Coffman) writes:

>in the next you say it will. The audio level controls output power
>*completely* in SSB mode. The mike gain pot may not be *labeled*
>POWER OUT, but it has exactly the same effect. You can think of the

Technically true. However, in practical situations using the MIC
gain control to control power is troublesome. So maybe this is a
different problem. I know that on my 440 it is next to impossible
to get it down to a reliable 5 watts PEP output using the MIC
gain, since any movement in the area of the mike itself will
change the PEP output substantially. There is no setting where I
can just sit back and ragchew - counting on about 5 watts PEP
output. It will vary from 2 watts to 25 watts or more. Now, by
using the audio processor I can get it a little closer, since
the audio level is held more steady. By using ALC control, I
get much closer to what I want...which is the way other
transceivers do it? Does anyone know? Is the audio circuit in
the 440 just unstable because the MIC gain is not a reliable,
steady power control?

Clark
WA3JPG


Gary Coffman

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Feb 5, 1996, 3:00:00 AM2/5/96
to
In article <4f4vag$f...@news-f.iadfw.net> fla...@iadfw.net (Floyd Adams) writes:
>ga...@ke4zv.atl.ga.us (Gary Coffman) wrote:
>
>>In article <4f0krb$k...@news-f.iadfw.net> fla...@iadfw.net (Floyd Adams) writes:
>>>Adjusting the Mic Gain on the 440 will NOT adjust the power like other
>>>rigs.
>
>>Why not, Floyd? Output power is a function of modulation level for
>>a SSB transmitter. If it weren't, the radio would put out as much
>>power when you weren't talking as when you do.
>
>The MIC Gain control will reduce the
>transmitted audio level to the point that you cannot be heard, but it
>does not reduce the power out.
>Power will reduce, because there is little or no audio transmitted.

Which is it, Floyd? In one sentence you say power won't be reduced,


in the next you say it will. The audio level controls output power
*completely* in SSB mode. The mike gain pot may not be *labeled*
POWER OUT, but it has exactly the same effect. You can think of the

SSB modulator as simply hetrodyning the voice signal up to some RF
frequency. Any change in voice level affects a corresponding change
in RF level.

The ALC turns down the gain of a *linear* RF amplifier while the
mike gain effectively turns down the gain of a *linear* audio
amplifier. Since both are linear, it doesn't matter which you
turn down, the effect is the same, less transmitted power.

The only possible time this wouldn't be true would be if you
were *overdriving* the audio and making it non-linear, then
power output wouldn't change linearly with audio level, but
we wouldn't want to do that would we? (Sometimes we do, and
it's called speech compression, but lets leave that out here
since we *really* don't want compression on RTTY tones because
the distortion would make them difficult to decode.)

Kenwood may have made a mistake here in leaving a pot labeled
POWER OUT off the radio, but the mistake wasn't a technical
one. It was the mistake of assuming amateurs would know that
turning the audio level down in SSB mode accomplishes the same
thing.

There is a technical reason for controlling power at the final
RF stage, but it is of no interest here. That is to reduce
levels of transmitted amplifier noise and carrier leakage in
proportion to the desired transmitted signal. With well designed
equipment, and reasonable power turn down ratios, this can be
ignored. You'd have to reduce power a *lot* (down in the milliwatts)
to approach an area of concern about residual noise transmission.

Bert Burland

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Feb 5, 1996, 3:00:00 AM2/5/96
to
jo...@emerald.net.com (John Gratton) wrote:

>I could not, however, find anything that would let
>me adjust the RF output while in LSB mode.

Try the Mic Gain knob.

>(Note, we couldn't find a 13 pin din connector
>to use the aux port on the 440, so we are going
>in through the mic jack).

Try Pacific Coast Parts(parts for Kenwood radios) 800-421-5080.

--
Bert Burland N.W.Texas USA

Bill Nelson

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Feb 6, 1996, 3:00:00 AM2/6/96
to
Clark Savage Turner (tur...@safety.ics.uci.edu) wrote:
: In <1996Feb5.1...@ke4zv.atl.ga.us> ga...@ke4zv.atl.ga.us (Gary Coffman) writes:

: >in the next you say it will. The audio level controls output power


: >*completely* in SSB mode. The mike gain pot may not be *labeled*
: >POWER OUT, but it has exactly the same effect. You can think of the

: Technically true. However, in practical situations using the MIC


: gain control to control power is troublesome. So maybe this is a
: different problem. I know that on my 440 it is next to impossible
: to get it down to a reliable 5 watts PEP output using the MIC
: gain, since any movement in the area of the mike itself will
: change the PEP output substantially. There is no setting where I
: can just sit back and ragchew - counting on about 5 watts PEP
: output. It will vary from 2 watts to 25 watts or more. Now, by
: using the audio processor I can get it a little closer, since
: the audio level is held more steady. By using ALC control, I
: get much closer to what I want...which is the way other
: transceivers do it? Does anyone know? Is the audio circuit in
: the 440 just unstable because the MIC gain is not a reliable,
: steady power control?

No, the problem is that you are not providing a steady input level to
the mike. The rig is performing exactly as it should.

Now, if you used a speech processor, such as one that compressed your
voice - the output level would be much more steady. However, those
circuits tend to increase background noise, as they attempt to adjust
ALL sounds to the same level.

Have you looked at the output waveform on a scope? I suspect that it would
show flattopping of your signal. This is just a guess, as I am not going to
try wiring a battery to the ALC on my rig to find out.

Bill

Danie Brynard

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Feb 7, 1996, 3:00:00 AM2/7/96
to
I also had a TS440S. I agree you cannot vary the SSB output power
on a TS440S except by controling the ALC voltage at the back of the
radio. I built myself a little box for controling the ALC when I
still had the 440, used it for QRP on HF.

The mic gain is a very unreliable and non-linear way of controlling
the 'rf' power. It is not meant for that. Try using the mic gain
when driving a 10mW transverter !

I went thru this whole story years ago - don't waste time with the
mic gain control.

I now have a ts690s: kenwood decided to implement a rf output
control on it, it works wonderful. Why have they decided to do it ?
Make up your own mind.

73 Danie zs6awk

Clark Savage Turner

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Feb 7, 1996, 3:00:00 AM2/7/96
to
In <4f6s9p$l...@odo.PEAK.ORG> bi...@PEAK.ORG (Bill Nelson) writes:

>... the problem is that you are not providing a steady input level to


>the mike. The rig is performing exactly as it should.

Yes, this makes sense.

>Now, if you used a speech processor, such as one that compressed your
>voice - the output level would be much more steady. However, those
>circuits tend to increase background noise, as they attempt to adjust
>ALL sounds to the same level.

That is what I normally did when I attempted to use my 440 for QRP SSB.
However, though my cheapo MFJ "Peak Reading" wattmeter showed pretty
steady 5 watts PEP output, I got a Palomar peak reading wattmeter
(it was digital? used discrete led's to show power output) that
seemed to respond much better and saw that my PEP output was still
varying widely depending on how I spoke to the mike and the time
of day, maybe the phase of the moon. The 440 compressor is an
audio compressor, but gets reasonable reports from critical guys.

>Have you looked at the output waveform on a scope? I suspect that it would
>show flattopping of your signal. This is just a guess, as I am not going to
>try wiring a battery to the ALC on my rig to find out.

I have not done that. I may do that soon.

Clark
WA3JPG

Gerry Feeney

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Jun 30, 2022, 12:43:33 PM6/30/22
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Gerry Feeney

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Jun 30, 2022, 12:54:59 PM6/30/22
to
Hi Danie….
Just came across your post via Google search….
I’m keying my Acom 1010 via the 7 pin remote connector on the rear panel of mt TS-440S however, even with the drive reduced as far as possible (10 - 15W) I’m getting a “G1” LED Illuminating. The ACOM manual that this indicates “a grid overload condition exists… reduce the drive power for safe operation”. Could you advise how this can be achieved ? I’m a newly licensed HAM on a rather steep learning curve 73 Gerry ☘️

Allodoxaphobia

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Jul 1, 2022, 7:41:01 AM7/1/22
to
On Thu, 30 Jun 2022 09:54:56 -0700 (PDT), Gerry Feeney wrote:
> On Wednesday, 7 February 1996 at 08:00:00 UTC, Danie Brynard wrote:
>> I also had a TS440S. I agree you cannot vary the SSB output power
>> on a TS440S except by controling the ALC voltage at the back of the
>> radio. I built myself a little box for controling the ALC when I
>> still had the 440, used it for QRP on HF.
>> The mic gain is a very unreliable and non-linear way of controlling
>> the 'rf' power. It is not meant for that. Try using the mic gain
>> when driving a 10mW transverter !
>> I went thru this whole story years ago - don't waste time with the
>> mic gain control.
>> I now have a ts690s: kenwood decided to implement a rf output
>> control on it, it works wonderful. Why have they decided to do it ?
>> Make up your own mind.
>> 73 Danie zs6awk

> Hi Danie….
> Just came across your post via Google search….

> I’m keying my Acom 1010 via the 7 pin remote connector on the rear
> panel of mt TS-440S however, even with the drive reduced as far as
> possible (10 - 15W) I’m getting a “G1” LED Illuminating. The ACOM
> manual that this indicates “a grid overload condition exists… reduce
> the drive power for safe operation”. Could you advise how this can be
> achieved ? I’m a newly licensed HAM on a rather steep learning curve
> 73 Gerry ☘️

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