animalinstincts wrote:

Hi I'm a little new to this news group, have been reading through it for a
few only a few weeks. I recently bought a 2M Kenwood tr-7850 at a low price
and
it works great, but, it would be even better if i could use it to monitor
slightly lower frequences to ~141Mhz from 143.9 which are used by fire and
police in my area. Did a thourough check of the web for out of band mods for
this radio and the only information I have is that it probably involves
clipping or rearranging programming resisters on the CPU board. However its
almost impossible to guess at which ones. There are also about a million
adjustments inside it, one of them should be able to affect the VCO. Does
anyone have any info on how to do this or a schematic for this radio? Thanks

--

If you can't find any information about extended frequency operating for
that (or nearly ANY) radio here,
www.mods.dk
then your chances are slim of finding that info at all. And since I don't
see any mod for said purpose there, at
http://www.mods.dk/view.php?ModelId=501
you are SOL. Sorry.

Thanks, Steve

animalinstincts wrote:

Hi I'm a little new to this news group, have been reading through it for a
few only a few weeks. I recently bought a 2M Kenwood tr-7850 at a low price
and
it works great, but, it would be even better if i could use it to monitor
slightly lower frequences to ~141Mhz from 143.9 which are used by fire and
police in my area. Did a thourough check of the web for out of band mods for
this radio and the only information I have is that it probably involves
clipping or rearranging programming resisters on the CPU board. However its
almost impossible to guess at which ones. There are also about a million
adjustments inside it, one of them should be able to affect the VCO. Does
anyone have any info on how to do this or a schematic for this radio? Thanks

--

If you can't find any information about extended frequency operating for
that (or nearly ANY) radio here,
www.mods.dk
then your chances are slim of finding that info at all. And since I don't
see any mod for said purpose there, at
http://www.mods.dk/view.php?ModelId=501
you are SOL. Sorry.

Thanks, Steve

animalinstincts wrote:

Hi I'm a little new to this news group, have been reading through it for a
few only a few weeks. I recently bought a 2M Kenwood tr-7850 at a low price
and
it works great, but, it would be even better if i could use it to monitor
slightly lower frequences to ~141Mhz from 143.9 which are used by fire and
police in my area. Did a thourough check of the web for out of band mods for
this radio and the only information I have is that it probably involves
clipping or rearranging programming resisters on the CPU board. However its
almost impossible to guess at which ones. There are also about a million
adjustments inside it, one of them should be able to affect the VCO. Does
anyone have any info on how to do this or a schematic for this radio? Thanks

--

If you can't find any information about extended frequency operating for
that (or nearly ANY) radio here,
www.mods.dk
then your chances are slim of finding that info at all. And since I don't
see any mod for said purpose there, at
http://www.mods.dk/view.php?ModelId=501
you are SOL. Sorry.

Thanks, Steve

Hi I'm a little new to this news group, have been reading through it for a
few only a few weeks. I recently bought a 2M Kenwood tr-7850 at a low price
and
it works great, but, it would be even better if i could use it to monitor
slightly lower frequences to ~141Mhz from 143.9 which are used by fire and
police in my area. Did a thourough check of the web for out of band mods for
this radio and the only information I have is that it probably involves
clipping or rearranging programming resisters on the CPU board. However its
almost impossible to guess at which ones. There are also about a million
adjustments inside it, one of them should be able to affect the VCO. Does
anyone have any info on how to do this or a schematic for this radio? Thanks

--

Just to let everyone know i did manage to do this. Found the info on the IC
(a decade counter) after enough searching. Then i figured out that the cpu
loads for example 1872 for 146mhz, 1616 for a 145, and a 1360for 144 mhz on
to the divider. Notice that a 1Mhz drop = 256 drop in the load group. Did
some simple math and to get 142Mhz it would have to load 848. So
144Mhz=1872=0010101010000 in binary and if you switch bits 10 and 11 you get
848 well close enough anyways. So I swapped the appropiate wires going to
the PLL and can now tune into the coppers. Going to add a switch to return
it to normal functioning as well. It took about 1.5 days of fumbling and
searching the net for info before I figured it out finally.


So not a very elegant or complete solution, would have been great if i could
just punch in the numbers from the panel. But it works anyways. The police
in this area have a high amount of digital traffic and its rather punishing
to listen to. I dont think this receiver supports ctccss. Just have to live
with that till I can afford a real scanner I suppose.

"animalinstincts" wrote in message
...
Hey Steve thanks for the reply. I went through those sites unfortuntly
they
didnt have the information i was looking for. However I have been doing
some
of my "research" and have located the PLL chip , a toshiba TL9122 decade
counter. 13 Bits are loaded from the CPU on to it, and there is a
142.0055Mhz crystal that it uses for comparison. So all I need now is the
pinout for that IC, and then drive the appropiate lines either high or low
to get frequencies outside the normal range.

Unfortunetly toshiba doesnt have information for that IC on its website so
I
am searching the bowels of the internet looking for it!

Just to let everyone know i did manage to do this. Found the info on the IC
(a decade counter) after enough searching. Then i figured out that the cpu
loads for example 1872 for 146mhz, 1616 for a 145, and a 1360for 144 mhz on
to the divider. Notice that a 1Mhz drop = 256 drop in the load group. Did
some simple math and to get 142Mhz it would have to load 848. So
144Mhz=1872=0010101010000 in binary and if you switch bits 10 and 11 you get
848 well close enough anyways. So I swapped the appropiate wires going to
the PLL and can now tune into the coppers. Going to add a switch to return
it to normal functioning as well. It took about 1.5 days of fumbling and
searching the net for info before I figured it out finally.


So not a very elegant or complete solution, would have been great if i could
just punch in the numbers from the panel. But it works anyways. The police
in this area have a high amount of digital traffic and its rather punishing
to listen to. I dont think this receiver supports ctccss. Just have to live
with that till I can afford a real scanner I suppose.

"animalinstincts" wrote in message
...
Hey Steve thanks for the reply. I went through those sites unfortuntly
they
didnt have the information i was looking for. However I have been doing
some
of my "research" and have located the PLL chip , a toshiba TL9122 decade
counter. 13 Bits are loaded from the CPU on to it, and there is a
142.0055Mhz crystal that it uses for comparison. So all I need now is the
pinout for that IC, and then drive the appropiate lines either high or low
to get frequencies outside the normal range.

Unfortunetly toshiba doesnt have information for that IC on its website so
I
am searching the bowels of the internet looking for it!

Just to let everyone know i did manage to do this. Found the info on the IC
(a decade counter) after enough searching. Then i figured out that the cpu
loads for example 1872 for 146mhz, 1616 for a 145, and a 1360for 144 mhz on
to the divider. Notice that a 1Mhz drop = 256 drop in the load group. Did
some simple math and to get 142Mhz it would have to load 848. So
144Mhz=1872=0010101010000 in binary and if you switch bits 10 and 11 you get
848 well close enough anyways. So I swapped the appropiate wires going to
the PLL and can now tune into the coppers. Going to add a switch to return
it to normal functioning as well. It took about 1.5 days of fumbling and
searching the net for info before I figured it out finally.


So not a very elegant or complete solution, would have been great if i could
just punch in the numbers from the panel. But it works anyways. The police
in this area have a high amount of digital traffic and its rather punishing
to listen to. I dont think this receiver supports ctccss. Just have to live
with that till I can afford a real scanner I suppose.

"animalinstincts" wrote in message
...
Hey Steve thanks for the reply. I went through those sites unfortuntly
they
didnt have the information i was looking for. However I have been doing
some
of my "research" and have located the PLL chip , a toshiba TL9122 decade
counter. 13 Bits are loaded from the CPU on to it, and there is a
142.0055Mhz crystal that it uses for comparison. So all I need now is the
pinout for that IC, and then drive the appropiate lines either high or low
to get frequencies outside the normal range.

Unfortunetly toshiba doesnt have information for that IC on its website so
I
am searching the bowels of the internet looking for it!