Kenwood TS-450s

[Yorklynyankee]

What could be causing low output on USB/LSB on all bands? The microphone
is good and works great on my another TS-450, the watt meter is a Bird
wattmeter and indicates full power on my another TS-450 under identical
conditions, using a constant tone (whistle) to drive the microphone,
using a 50 ohm dummy load, the carrier knob and microphone gain are full
up. The same radio puts out full 100+ watts on all bands when using CW
or FSK.




--
Yorklynyankee

[atec77]

Is carrier normal , is it is then you have a mic circuit /gain problem
or alc problem ?

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X-No-Archive: Yes

[Fred McKenzie]

In article <kncch6$18v$1...@dont-email.me>, atec77 <"atec77 "@hotmail.com>
wrote:

> Is carrier normal , is it is then you have a mic circuit /gain problem
> or alc problem ?

Yorklynyankee, you did not mention how low was the power. If it was in
the neighborhood of 80 watts, I would not worry about it unless there
were reports of distorted audio.

It sounds like the carrier is normal, judging by the CW/FSK power.

I suggest you download the TS-450/690 service manual, and look for
adjustments that involve ALC and/or balanced modulator.

One place that should have the manual is: <http://www.mods.dk>. You
must register in order to download, and there are limits on how often
unless you donate.

Fred
K4DII

[Channel Jumper]

Its probably tired from being used too much on 11 meters.....

Maybe it is folding back because of a high SWR - you don't run CW and
FSK in the same part of the band as phone. Are you checking it into a
true 50 ohm dummy load or the antenna?

Did you check your antenna since last winter - maybe it stretched from
ice / wind blowing etc.
Maybe your coax has issues.

No way to know because my crystal ball is broke.

There is always a certain segment of the population that doesn't
understand SSB and always wants 100% performance out of everything and
will strive to squeeze every last watt out of something, regardless of
if it worked ok or not before they started messing with it.

In CB talk that is called Peak n Tune.

You won't ever notice any difference in perceived signals strength
between 80 watts and 100 watts on most phone conversations.. I wouldn't
worry about it.

Are you fully modulating the signal when you are measuring it with your
Bird meter? CQ CQ CQ K K K P P P D D D You will only see full signal
strength when it is fully modulated...
CW and FSK is 100% duty cycle - fully modulated all the time.

Running the transmitter at full power for any length of time will damage
it on FSK.
Its not designed to be used that way with more then about 30 or 40
watts.

Does it have an auto tuner?

Is it turned on or off?




--
Channel Jumper

[you]

In article <Yorklynyan...@radiobanter.com>,

Channel Jumper is an Idiot, and obviously has never operated a TS-450....

More than likely what you are seeing is the ALC foldback, lowering the
Gain, in the TX Gain Stage, that drives the Final Amp Circuit. Having
both TS450's and TS 690's here, this is very common, to have the Radio
do this when it comes from the Factory, or a Factory Trained Tech, after
a Service Call.... the Factory sets the ALC High, so that the radio will
ALWAYS meet, the published IMD Spec. You can, by readjusting the ALC
Feedback Circuit, setup the TX to output TX PEP Power and a reasonable
Average Power as shown on a non-PEP Wattmeter, without compromising the
IMD level of the resultant Transmissions, in any significant way.

Just Say'en.... YMMV.....

[Yorklynyankee]

Thank all of you for your suggestions. Just for the record, I don't
operate CB radio, I am a retired Research & Development electrical
engineer from HP, and I have a masters degree in Electrical
Engineering.... now to answer some of the questions. As I mentioned in
my first posting the radio is connected to a 50 dummy load. By low
output power I mean 5~10 watts, I have tried two different microphones.
I have another Kenwood TS-450 so I have a working radio to compare their
outputs. When I whistle into the radio using USB/LSB on any bands at any
frequency, the radio will only put out 5~10 watts. Whereas under
identical conditions the working radio will put out 100 watts. There is
absolutely NO DOUBT that this radio's USB/LSB is not working. The same
radio puts out 100+ watts on CW and FSK. I suspect something in the
balanced modulator, but I am looking for someone who has encountered a
problem like this before. This radio is known for having some common
problems, like C104, so I was hoping that there was another frequently
failed component that causes this problem.




--
Yorklynyankee

[Channel Jumper]

you;805175 Wrote:
> In article Yorklynyan...@radiobanter.com,
> Yorklynyankee Yorklynyan...@radiobanter.com wrote:
> [color=blue][i]

>
>
> Channel Jumper is an Idiot, and obviously has never operated a
> TS-450....
>
>

> Just Say'en.... YMMV.....

Yep =- that is right, I don't play around with junk!

Throw er in the gutter and go buy anutter...




--
Channel Jumper

[natep...@gmail.com]

My clubs radio (ts-450s) just started doing the exact same thing. Did you ever find a fix to this issue?

[Fred McKenzie]

In article <d47f8ece-95b9-495b...@googlegroups.com>,

Nate-

I have the TS-690, which is a TS-450 with Six Meters. I also have other
older Kenwood equipment. They all suffer from a common problem:
leaking electrolytic capacitors.

In the case of the TS-690, the first problem was when an electrolytic
capacitor in the audio circuit leaked, and the leaked chemical corroded
one of the circuit paths. I was lucky to find it, and was able to
repair it by replacing the capacitor and running a wire jumper from one
end of the path to the other.

In other equipment such as the TS-50, there have been numerous problems
with capacitors. Some I have been able to fix, but they keep cropping
up. So far, I have ruined the foil of several when trying to remove bad
surface-mount capacitors. It can be very frustrating!

Good Luck.

73, Fred
K4DII

[csmele...@gmail.com]

Having same problem with my 450. Did you find the problem? Colin...

[Allodoxaphobia]

And you believe "Yorklynyankee" has been checking back on this thread
for nearly FOUR YEARS?

[Fred McKenzie]

In article <4c3d2940-07c0-45cd...@googlegroups.com>,

Colin-

I have the TS-690, which is a TS-450 with Six Meters. So far, the only
obvious problem I have had was due to a leaking electrolytic capacitor
in the audio output circuit. It seems the leaked electrolyte ate
through one of the foil circuits in series with audio output. I was
able to repair it by replacing the capacitor and adding a jumper across
the foil.

I also have had problems with an old Kenwood TS-50. Several
electrolytic capacitors have gone bad, sometimes leaking. It can be
very frustrating fixing one problem and then finding more that were
hidden by the first. I conclude that Kenwood has had problems with
electrolytic capacitors.

Good luck.

Fred
K4DII

[schri...@gmail.com]

My 450 starts sending Morse code letters U & L as soon as I power it up master reset does not fix the problem and the only time it will stop is momentarily when I change frequencies then it starts back up again. Has anyone encountered this problem and can anyone point me in the right direction to troubleshoot it? Thank you Sam in Colorado. N0KEI

[Fred McKenzie]

In article <4779009c-1b33-4b25...@googlegroups.com>,

N0KEI-

While I haven't had that exact problem, I have had something similar.
It turned out that the rig was set for an automatic key but a simple key
was plugged in. The result was that one side of the automatic key input
was grounded by the single circuit key plug.

In my case, the keyed tones could be generated in modes other than CW,
even though the transmitter did not get keyed.

Fred
K4DII

[bambaz...@gmail.com]

I just bought a 450 that had the same problem I found out by research that C104 on the board edge 450 mf/10v near the filters was leaky and had wet the traces. You need to clean up very well and replace the capacitor. Another fault was a relay on the top board had a dry joint on its soldering you can tell a dry joint because it has a dark ring around the pin thet didn't get soldered
good luck

[Allodoxaphobia]

Well, after 5+ years, he's either already been lucky,
went SK, or has a new(er) rig.

When will you google groopers ever learn?

[w8ml...@gmail.com]

my ts450 has a alc problem i turn it on and it works ok for about 3 minutes and then the alc starts rising and goes out of control reset alc and power drops from 80 watts to 5 watts any thoughts? radio has never been on 11 has never been modded

[Catweazel]

On 08/01/2019 19:56, w8ml...@gmail.com wrote:
>
> my ts450 has a alc problem i turn it on and it works ok for about 3 minutes and then the alc starts rising and goes out of control reset alc and power drops from 80 watts to 5 watts any thoughts? radio has never been on 11 has never been modded
>

In a general way, sounds like a component failing/ failure. If you can
identify the location of components associated with the alc function,
apply freezer-spray to see if the normal function is returned, or not.
£0.02
--

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[Fred McKenzie]

In article <c6094349-e5eb-4795...@googlegroups.com>,

My TS-690 is a TS-450 with Six Meters. Several years ago a problem
turned out to be caused by a leaking electrolytic capacitor. The
leakage corroded a circuit trace, opening the circuit.

My old TS-50 has numerous bad electrolytic capacitors. I gave up trying
to fix it. (I was doing more harm than good!)

Kenwood seems to have used some poor electrolytic capacitors, and they
are causing problems in their old age.

Fred
K4DII

[Catweazel]

FWIW my 20yr old IC706mk2 suffered failure of an (leaking) electrolytic
capacitor a few years ago, and corroded part of the track to which it
was connected.

[Bob Wilson]

For those of us who also follow changes in PC motherboards: A few years
ago, I'd have to do some research to get a more precise time, several of
the major, and respected, motherboard makers had problems with infant
mortality. Their electrolytics were going bad a few months after the
board was put into service. I think there was just one capacitor maker
who was responsible for most of the bad ones, but whoever it was must
have made the caps used for many of the motherboards out there! Earlier,
and later, boards from the same manufacturers had more usual failure
statistics. I remember seeing posted photos of rows of electrolytics,
filters for power supply lines, with most of their tops swelled outward.
So I wonder if these failures are related...
Bob Wilson, WA9D