No PL Tone

[jimbo]

Well, I have checked and checked and my Kenwood TM-241A just will not
transmit through a repeater. It works just fine on simplex. And it
receives just fine via a repeater. But I cannot get any signal through
a repeater. Exactly as if I had no PL tone or the wrong PL tone. But I
know the tone indicated is correct. So my conclusion is that the radio
either doesn't transmit a PL tone or it doesn't transmit the tone
indicated.

Does anyone have any insight as to how difficult and expensive a repair
would be? The radio is almost 10 years old, so a costly repair job is
not justified.

Thanks for any advice, jimbo

[Sarge]

Jimbo, are you sure you don't have the tone squelch on?
Most repeaters are set to require a tone but to send out a tone.
so try just encode and no decode. (you probably know all of this so if you
do, sorry about that)

Post by jimbo
Well, I have checked and checked and my Kenwood TM-241A just will not
transmit through a repeater. It works just fine on simplex. And it
receives just fine via a repeater. But I cannot get any signal through
a repeater. Exactly as if I had no PL tone or the wrong PL tone. But I
know the tone indicated is correct. So my conclusion is that the radio
either doesn't transmit a PL tone or it doesn't transmit the tone
indicated.
Does anyone have any insight as to how difficult and expensive a repair
would be? The radio is almost 10 years old, so a costly repair job is
not justified.
Thanks for any advice, jimbo

[Raymond Sirois]

Post by jimbo
Well, I have checked and checked and my Kenwood TM-241A just will not
transmit through a repeater. It works just fine on simplex. And it
receives just fine via a repeater. But I cannot get any signal through
a repeater. Exactly as if I had no PL tone or the wrong PL tone. But I
know the tone indicated is correct. So my conclusion is that the radio
either doesn't transmit a PL tone or it doesn't transmit the tone
indicated.
Does anyone have any insight as to how difficult and expensive a repair
would be? The radio is almost 10 years old, so a costly repair job is
not justified.
Thanks for any advice, jimbo

Many radios have seperate settings for send CTCSS and receive CTCSS
tones. You may want to double check your settings...


Raymond Sirois
SysOp: The Lost Chord BBS
607-733-5745
telnet://thelostchord.dns2go.com:6000

[jimbo]

Thanks for the replies. My TM-241A doesn't have the optional TSU-6 tone
decoder installed, and the the display shows "T" which is supposed to
indicate tone encode only. So, I don't think tone decoding/tone squelch
is the problem.

Any other thoughts?

Thanks, jimbo

[David 01]

Post by jimbo
Thanks for the replies. My TM-241A doesn't have the optional TSU-6 tone
decoder installed, and the the display shows "T" which is supposed to
indicate tone encode only. So, I don't think tone decoding/tone squelch
is the problem.
Any other thoughts?
Thanks, jimbo

Have you tried doing a reset? You'll lose all programming but I have a
TM-231A and sometimes it gets brainlock and has to be reset.

David

[jimbo]

I did one reset several days ago and thought the problem had been
solved. But after one day, the same symptoms returned. I just did
another reset. Don't know the results yet. The radio is ten years old.
The manual says the battery will last about five years. But I don't
have any problems with frequency, etc. stored in memory. Still, I guess
a weak battery could be causing a problem.

Thanks, jimbo

[john graesser]

Post by jimbo
Well, I have checked and checked and my Kenwood TM-241A just will not
transmit through a repeater. It works just fine on simplex. And it
receives just fine via a repeater. But I cannot get any signal through
a repeater. Exactly as if I had no PL tone or the wrong PL tone. But I
know the tone indicated is correct. So my conclusion is that the radio
either doesn't transmit a PL tone or it doesn't transmit the tone
indicated.
Does anyone have any insight as to how difficult and expensive a repair
would be? The radio is almost 10 years old, so a costly repair job is
not justified.

Have you hooked up to a test instrument of any kind to see what/if any tone
is being transmitted.

It could be your radio is misprogrammed and the wrong tone is being sent or
no tone is being sent.

It could be that your tone generator has drifted and is sending the tone at
the wrong frequency.

First check what tone is going out, and if no tone is going out then check
the circuit that combines the audio with the tone, then check the tone
generation circuitry.

A radio set to receive your transmit audio with the speaker hooked to a freq
counter or oscope will show what freq tone is being transmitted, just don't
speak and all that will be there is your subtone.
thanks, John.

[jimbo]

Thanks for your thoughtful reply. The only test equipment I have is a
power/swr meter, (Diamond SX200). What would you recommend for
additional test equipment to diagnose this problem?

jimbo

[David 01]

Post by jimbo
Thanks for your thoughtful reply. The only test equipment I have is a
power/swr meter, (Diamond SX200). What would you recommend for
additional test equipment to diagnose this problem?
jimbo

Did you test it after the reset?

[nana]

Find someone with an HT and test it on simplex across the room. It reduces a
LOT of confusion that way.

Brad.

Post by jimbo
Thanks for your thoughtful reply. The only test equipment I have is a
power/swr meter, (Diamond SX200). What would you recommend for
additional test equipment to diagnose this problem?
jimbo

[jimbo]

I have a radio in the truck and this one in the house. Yes, the radio
works on simplex and it receives OK from a repeater. That is why I
think it is not transmitting a PL tone or maybe it is not transmitting
the tone indicated.

John suggested a way to verify the PL tone, and I asked about what
equipment might be appropriate. I would still like a recommendation.

After one reset, the radio seemed to work OK through the repeater, but
after a day or so, it reverted back to the same behaviour. The last
reset also seems to have "fixed" the problem again, but I don't know
for how long.

Thanks, jimbo

[David 01]

Post by jimbo
I have a radio in the truck and this one in the house. Yes, the radio
works on simplex and it receives OK from a repeater. That is why I
think it is not transmitting a PL tone or maybe it is not transmitting
the tone indicated.
John suggested a way to verify the PL tone, and I asked about what
equipment might be appropriate. I would still like a recommendation.
After one reset, the radio seemed to work OK through the repeater, but
after a day or so, it reverted back to the same behaviour. The last
reset also seems to have "fixed" the problem again, but I don't know
for how long.
Thanks, jimbo

Looks like your problem is that your radio's brains are getting scrambled
and a reset is needed occasionally. Replacement of the memory battery may
take care of the problem and then you won't need to do the other stuff.
Resetting doesn't necessarily fix anything. It just corrects a side effect
of "the" problem. Therefore until you fix "the" problem, you'll probably
have to continue resetting the radio every now and then.

[Pete KE9OA]

Hi Jim,
A service moniter would do the trick................otherwise, a
spectrum analyzer. Usually with a rig of this type, there is a D/A convertor
onboard the microcontroller. There could be a problem with the pot that
controls the PL level. Usually, there is one pot for mic input deviation and
another for PL deviation.

Pete

Post by jimbo
Thanks for your thoughtful reply. The only test equipment I have is a
power/swr meter, (Diamond SX200). What would you recommend for
additional test equipment to diagnose this problem?
jimbo

[bob]

Jimbo,

Find a ham with a transceiver that has PL DECODE capability. Have him set
his DECODER to open his squelch on the PL tone you think you are sending
from your radio. Transmit to him on simplex, using the PL tone ENCODE and
see if his radio opens squelch. Your radio may not be sending the correct
PL. Or, it may not be sending it with enough deviation. Some repeaters
require a bit more than .5 khz deviation on the PL to open the repeater up.

Hope this helps.

73,

Bob K5INW

Post by jimbo
Well, I have checked and checked and my Kenwood TM-241A just will not
transmit through a repeater. It works just fine on simplex. And it
receives just fine via a repeater. But I cannot get any signal through
a repeater. Exactly as if I had no PL tone or the wrong PL tone. But I
know the tone indicated is correct. So my conclusion is that the radio
either doesn't transmit a PL tone or it doesn't transmit the tone
indicated.
Does anyone have any insight as to how difficult and expensive a repair
would be? The radio is almost 10 years old, so a costly repair job is
not justified.
Thanks for any advice, jimbo

[jimbo]

Thanks for the great suggestion. I will give that a try. What a great
and simple way to check for PL tone transmit. The radio has never had a
problem with PL before, but it sure has the symptoms of something wrong
with PL now.

Do you think a weak internal battery could cause this problem? I
haven't noticed any evidence of battery failure, but maybe a battery
about to fail could cause such a problem?

Thanks, jimbo

[David 01]

YES!

Post by jimbo
Thanks for the great suggestion. I will give that a try. What a great
and simple way to check for PL tone transmit. The radio has never had a
problem with PL before, but it sure has the symptoms of something wrong
with PL now.
Do you think a weak internal battery could cause this problem? I
haven't noticed any evidence of battery failure, but maybe a battery
about to fail could cause such a problem?
Thanks, jimbo

[Pete KE9OA]

A weak Lithium backup battery has caused weird problems in some of the HP
test equipment that I have...........removing the bad battery clears up the
problem, but of course, I lose my saved information. The Racal 6790
receivers had the same types of weird problems when their backup battery
would go bad.
When I was working at the Sanyo service center, the same problem was noted
with some of their answering machines.

Pete

Post by jimbo
Thanks for the great suggestion. I will give that a try. What a great
and simple way to check for PL tone transmit. The radio has never had a
problem with PL before, but it sure has the symptoms of something wrong
with PL now.
Do you think a weak internal battery could cause this problem? I
haven't noticed any evidence of battery failure, but maybe a battery
about to fail could cause such a problem?
Thanks, jimbo