TMG707 - 1750 Hz tone bust
 

Hello,
I am looking for a little help.
I have an Kenwood TMG707A which I have reset the chip
diodes / resistors so that it is the European (TMG707E)
version. All is well with the frequency coverage / bandplans
etc.
But the 1750Hz tone is so low in volume that it can not be used
to access the repeaters that still have not got CTCSS on them.
CTCSS tones work OK.
Has any one got a service manual / circuit diagram or knows how
to adjust the 1750hz tone level. Nothing else needs adjusting
only the volume of the 1750hz tone - the deviation checks out OK
and the rig sounds great.

Thanks in advance Martin

"MR NO SPAM" wrote in message
...
I don't have a manual for it but a lot of radios have a pot labeled tone
volume. Take a look. I'm confused though, your statement must have a
typo..
IF the repeater doesn't have CTCSS / PL access on it, why worry about the
tone? There should be a switch to disable it. MNS.

This person is in Europe... the standard for
a long time was to open the repeater rx
via a short 1750Hz burst at the beginning
of your tx. Probably still a lot of those
machines around.

For the Original Poster: Do you have a
copy of the docs? I found this link:

http://www.xs4all.nl/~pa0nhc/Modific...707/DevAdj.htm

it explains how to set your deviation.
You could always talk softer, and
increase your overall deviation, that
might work, and it might not. There
might be a tone deviation in that menu
the link describes... that would explain
a lot, since you've changed to Euro
standards but might not have changed
the tone deviation from low (use for
PL/CTCSS in USA) to high (used
for burst tone access). Good luck!
__
Steve
KI5YG
..

"MR NO SPAM" wrote in message
...
I don't have a manual for it but a lot of radios have a pot labeled tone
volume. Take a look. I'm confused though, your statement must have a
typo..
IF the repeater doesn't have CTCSS / PL access on it, why worry about the
tone? There should be a switch to disable it. MNS.



Here in the UK not all repeaters are yet fitted with CTCSS for access.
and the old system was to transmit a 1750Hz tone burst approx 200ms
long then a carrier with / without audio to make the repeater switch on
the Tx and latch. The Time out timer then starts to count down.
On some repeaters once the input signal had dropped and he squelch
closed on the RX the next received carried caused the repeater to remain
latched and the T/O timer was reset if there was no other carrier for 5
seconds
or so the logic sent the callsign and the repeater closed down un till the
next time
a 1750Hz tone was received.

So to access these older yet to be upgraded boxes I need to get the 1750Hz
tone sorted out.

Any one got a circuit for the TMG707 either version ?

I'm fully aware of what "tone burst" is and how it works, as well as
CTCSS/PL.. It was the sentence in the original post that threw me off. MNS.

"Martin" wrote in message
...

"MR NO SPAM" wrote in message
...
I don't have a manual for it but a lot of radios have a pot labeled tone
volume. Take a look. I'm confused though, your statement must have a
typo..
IF the repeater doesn't have CTCSS / PL access on it, why worry about
the
tone? There should be a switch to disable it. MNS.



Here in the UK not all repeaters are yet fitted with CTCSS for access.
and the old system was to transmit a 1750Hz tone burst approx 200ms
long then a carrier with / without audio to make the repeater switch on
the Tx and latch. The Time out timer then starts to count down.
On some repeaters once the input signal had dropped and he squelch
closed on the RX the next received carried caused the repeater to remain
latched and the T/O timer was reset if there was no other carrier for 5
seconds
or so the logic sent the callsign and the repeater closed down un till the
next time
a 1750Hz tone was received.

So to access these older yet to be upgraded boxes I need to get the 1750Hz
tone sorted out.

Any one got a circuit for the TMG707 either version ?