FM on (RS) TRC-485?
 

I own a TRC-485 AM/SSB xcvr.
I noticed when looking at the display that there is an FM indicator.

How can I receive/xmit in FM mode?
Where is the mod for this?

Thank you.

240-Robert

It's possible that the same display is used for other radios
that use FM. FM is not intended for use on the CB band,
but some folks do use it there. They do not use a regular CB
for this. You can't get FM on your AM/SSB radio because the guts of the
radio
is a very different beast indeed.
Although it might have been a good idea for the FCC to
to make use of FM on 27MHz. It would have prevented
"skip" and that would have made them happy.
73zzzzzz

240-Robert wrote:

I own a TRC-485 AM/SSB xcvr.
I noticed when looking at the display that there is an FM indicator.

How can I receive/xmit in FM mode?
Where is the mod for this?

Thank you.

240-Robert

"Barry" wrote in message
...
It's possible that the same display is used for other radios
that use FM. FM is not intended for use on the CB band,

Its used in the UK on their 11m band.

http://www.fact-index.com/c/cb/cb_radio_uk.html

but some folks do use it there. They do not use a regular CB
for this. You can't get FM on your AM/SSB radio because the guts of the
radio

Depending on the radio you may be able to use the steep side skirts of the
AM filter as a form of slope detector for FM. I've done it using an Icom
IC-706 ham rig. The problem is you have to be able to tune significantly off
the channel center frequency to put the signal center frequency on the skirt
of the AM filter. Normal unmodified CBs don't allow such frequency sliding.

http://www.tpub.com/content/neets/14.../14184_163.htm

http://www.somerset.net/arm/fm_only_lowtech.html

is a very different beast indeed.
Although it might have been a good idea for the FCC to
to make use of FM on 27MHz. It would have prevented
"skip" and that would have made them happy.

No it would not have done so. I've heard enough 10m FM DX to know. Try
monitoring 29.600 MHz which is the Ham FM national calling frequency on FM.

http://www.qsl.net/g3xbm/10m.htm (look under 10m FM)

--
Leland C. Scott
KC8LDO

Wireless Network
Mobile computing
on the go brought
to you by Micro$oft

"Barry" wrote in message
...
It's possible that the same display is used for other radios
that use FM. FM is not intended for use on the CB band,
but some folks do use it there. They do not use a regular CB
for this. You can't get FM on your AM/SSB radio because the guts of the
radio
is a very different beast indeed.
Although it might have been a good idea for the FCC to
to make use of FM on 27MHz. It would have prevented
"skip" and that would have made them happy.
73zzzzzz

DUDE.....you are clearly clueless! You have NO idea how things work, "SKIP"
is skip...doesnt care what the modulation/deviation is PERIOD.(AM) broadcast
band at night skips, Ham(FM) 10,6 and 2 meters skips during the day,Ham
(SSB) skips on 80/75/40/30/20/17/15 Meter bands day and night. Television
(VSB) skips during the day in the summertime.
The UK operators have FM service (for years) on the 26.965-27.405Mhz.
BTW..it's VERY easy to Phase modulate a AM CB rig to convert it to Narrow
FM. Adding a FM detector to the receiver is also easy, so the "GUTS" are not
all that differant. Interferance between FM radios is a lot less due to the
needed "Capture Ratio" .
Quit handing out "Facts" until you know what your talking about Barry..you
**** off the rest of us that DO know how radio works.

Depending on the radio you may be able to use the steep side skirts of the
AM filter as a form of slope detector for FM. I've done it using an Icom
IC-706 ham rig. The problem is you have to be able to tune significantly off
the channel center frequency to put the signal center frequency on the skirt
of the AM filter. Normal unmodified CBs don't allow such frequency sliding.

I've done it with a regular CB. I just turn the clarifier to either edge. It isn't
perfect, but quite understandable. My radio has a narrow receive bandwidth
compared to some radios. I'm still using my TRC-451 (Cobra 146). Other
radios I've done this with include a PC-122 (TRC-465). All stock. The last
thing I want is my transmit frequency to change after spending good money
on a PROPER tune-up to factory specs. No ruined clarifiers here. If I want
to go off-frequency, I have a 2950. It's clarifier is also locked. It shifts in
100Hz increments. Why chop it up for a clarifier mod?

snip
BTW..it's VERY easy to Phase modulate a AM CB rig to convert it to Narrow
FM. Adding a FM detector to the receiver is also easy, so the "GUTS" are
not
all that differant. Interferance between FM radios is a lot less due to
the
needed "Capture Ratio" .
Quit handing out "Facts" until you know what your talking about Barry..you
**** off the rest of us that DO know how radio works.


Do you remember the FM3 kit? I can't find anyone that sells that anymore. I
did find the schematic though. I just wish I could buy it ready made.
'Course I probably could use a refresher so maybe it's better that I just
build the dang thing. :-)

Dr.X

Your probably the only one here that knows that.......

you **** off the rest of us that DO know how radio works.
.................................................. ......
"Dr.X" wrote:

snip
BTW..it's VERY easy to Phase modulate a AM CB rig to convert it to Narrow
FM. Adding a FM detector to the receiver is also easy, so the "GUTS" are
not
all that differant. Interferance between FM radios is a lot less due to
the
needed "Capture Ratio" .
Quit handing out "Facts" until you know what your talking about Barry..


Do you remember the FM3 kit? I can't find anyone that sells that anymore. I
did find the schematic though. I just wish I could buy it ready made.
'Course I probably could use a refresher so maybe it's better that I just
build the dang thing. :-)

Dr.X

"Barry" wrote in message
...
Your probably the only one here that knows that.......
you **** off the rest of us that DO know how radio works.
.................................................. .....

wtf are you talkin' about?

Dr.X