I would like to add an analogue signal strength meter to my Icom R75
receiver. Has anyone managed to do this, and what's involved? I'm
looking to take a 'real' indication of signal strength from the AGC
line, not just monitoring the audio output.

Thanks

Sounds like a good idea to me.I dont know how to do it
though.Surely,someone with more knowledge than I about such things will
be along soon to provide more information.
cuhulin

On 18 Aug 2006 05:46:33 -0700, "Jim" wrote:

I would like to add an analogue signal strength meter to my Icom R75
receiver. Has anyone managed to do this, and what's involved? I'm
looking to take a 'real' indication of signal strength from the AGC
line, not just monitoring the audio output.

Thanks
???

My R75 has an S meter. It appears to mimic a VU meter in the SSB mode
because there is only ''power'' during modulation , but shows signal
strength normally in the AM mode.

David wrote:
On 18 Aug 2006 05:46:33 -0700, "Jim" wrote:

I would like to add an analogue signal strength meter to my Icom R75
receiver. Has anyone managed to do this, and what's involved? I'm
looking to take a 'real' indication of signal strength from the AGC
line, not just monitoring the audio output.

Thanks
???

My R75 has an S meter. It appears to mimic a VU meter in the SSB mode
because there is only ''power'' during modulation , but shows signal
strength normally in the AM mode.

Same here - the S-meter on my R-75 appears to behave in near-perfect
analogy to a mechanical/analogue S-meter, the only difference being
that the electronic/digital meter doesn't get the finest gradations of
signal strength variation. Otherwise, it leaves no doubt as to the
accurate strength of the signal, irrespective of audio (audio strength
plays no role in signal strength reading in AM - even if there is a
silent carrier, the meter deflects; and on SSB, it deflects only when
the audio is present, as it should).

Bruce Jensen

In article .com,
"bpnjensen" wrote:

David wrote:
On 18 Aug 2006 05:46:33 -0700, "Jim" wrote:

I would like to add an analogue signal strength meter to my Icom R75
receiver. Has anyone managed to do this, and what's involved? I'm
looking to take a 'real' indication of signal strength from the AGC
line, not just monitoring the audio output.

Thanks
???

My R75 has an S meter. It appears to mimic a VU meter in the SSB mode
because there is only ''power'' during modulation , but shows signal
strength normally in the AM mode.

Same here - the S-meter on my R-75 appears to behave in near-perfect
analogy to a mechanical/analogue S-meter, the only difference being
that the electronic/digital meter doesn't get the finest gradations of
signal strength variation. Otherwise, it leaves no doubt as to the
accurate strength of the signal, irrespective of audio (audio strength
plays no role in signal strength reading in AM - even if there is a
silent carrier, the meter deflects; and on SSB, it deflects only when
the audio is present, as it should).

Again a digital version of an analog function has no additional inherent
value over analog but it could. An example here would be a low and peak
temporary hold display. Normal would be green, max would be red and blue
min signal colors. The red and blue would last a second or two so the
green level indication could respond quickly to enhance the display.

--
Telamon
Ventura, California

It takes physical properties to push a solid thingy such as Air
around.Otherwise,you are not going to ''hear'' anything in your little
feeble mixed up mind but your own imsginations.
cuhulin

"Telamon" wrote in message
...

Again a digital version of an analog function has no additional inherent
value over analog but it could. An example here would be a low and peak
temporary hold display. Normal would be green, max would be red and blue
min signal colors. The red and blue would last a second or two so the
green level indication could respond quickly to enhance the display.

I like the SDR-1000's digital meter (in dBm), as the averaging function
(rate) can be adjusted to the user's liking, or turned off. The peak hold
and normal display colors (in gradient color hues) can be changed, too, for
best visibility. There is also a really cool "analog" representation of an
s-meter as an option, that displays in true s-units and incorporates the
peak hold feature. The "needle" changes color briefly at the peak reading.
It's a high-resolution and realistic representation of an S-meter, and
floats in a separate window so you can place it on the Windows desktop
wherever you like. Finally, because the SDR-1000 is user-calibrated with a
Elecraft XG-1 or other signal meter, the digital meter and the "analog"
s-meter are highly accurate across their range. My SDR-1000 blog entry from
April 13th shows this S-meter in its prior form, before it was changed to a
"floating" window.

Guy Atkins
Puyallup, WA
www.sdr-1000.blogspot.com

In article ,
"Guy Atkins" wrote:

"Telamon" wrote in message
...

Again a digital version of an analog function has no additional inherent
value over analog but it could. An example here would be a low and peak
temporary hold display. Normal would be green, max would be red and blue
min signal colors. The red and blue would last a second or two so the
green level indication could respond quickly to enhance the display.

I like the SDR-1000's digital meter (in dBm), as the averaging function
(rate) can be adjusted to the user's liking, or turned off. The peak hold
and normal display colors (in gradient color hues) can be changed, too, for
best visibility. There is also a really cool "analog" representation of an
s-meter as an option, that displays in true s-units and incorporates the
peak hold feature. The "needle" changes color briefly at the peak reading.
It's a high-resolution and realistic representation of an S-meter, and
floats in a separate window so you can place it on the Windows desktop
wherever you like. Finally, because the SDR-1000 is user-calibrated with a
Elecraft XG-1 or other signal meter, the digital meter and the "analog"
s-meter are highly accurate across their range. My SDR-1000 blog entry from
April 13th shows this S-meter in its prior form, before it was changed to a
"floating" window.

Analog or digital dBm is certainly more useful that s units.

You can program any kind of display you like on the computer supported
radios.

I would not want the averaging on at all preferring that the display
update as fast as possible so that the rate of signal fluctuation can
be seen in real time. The drawback is that with rapidly changing signal
you would have a tough time seeing the min and max and that is where
the min and max hold for a second or two with the different colors
would display. I've seen this type of display on audio VU metering and
I think it would be good for signal strength indicator.

--
Telamon
Ventura, California

Telamon wrote:
In article ,
"Guy Atkins" wrote:

"Telamon" wrote in message
...

Again a digital version of an analog function has no additional inherent
value over analog but it could. An example here would be a low and peak
temporary hold display. Normal would be green, max would be red and blue
min signal colors. The red and blue would last a second or two so the
green level indication could respond quickly to enhance the display.

I like the SDR-1000's digital meter (in dBm), as the averaging function
(rate) can be adjusted to the user's liking, or turned off. The peak hold
and normal display colors (in gradient color hues) can be changed, too, for
best visibility. There is also a really cool "analog" representation of an
s-meter as an option, that displays in true s-units and incorporates the
peak hold feature. The "needle" changes color briefly at the peak reading.
It's a high-resolution and realistic representation of an S-meter, and
floats in a separate window so you can place it on the Windows desktop
wherever you like. Finally, because the SDR-1000 is user-calibrated with a
Elecraft XG-1 or other signal meter, the digital meter and the "analog"
s-meter are highly accurate across their range. My SDR-1000 blog entry from
April 13th shows this S-meter in its prior form, before it was changed to a
"floating" window.

Analog or digital dBm is certainly more useful that s units.

You can program any kind of display you like on the computer supported
radios.

I would not want the averaging on at all preferring that the display
update as fast as possible so that the rate of signal fluctuation can
be seen in real time. The drawback is that with rapidly changing signal
you would have a tough time seeing the min and max and that is where
the min and max hold for a second or two with the different colors
would display. I've seen this type of display on audio VU metering and
I think it would be good for signal strength indicator.

--
Telamon
Ventura, California

The JRC NRD-545's S meter can show a signal's "max peak" reading, where
the highest reading signal "bar" remains lit for a second or two after
the signal strength starts to fall. Meanwhile, the actual strength of
the signal can still be seen at any given moment, as the S-meter
continues to function as usual. It's just that the one bar showing the
peak reading remains lit. I really liked that feature of the 545 (I now
have a Ten-Tec RX340).

I never understood the DBm scale, which my RX340 has in addition to the
usual S unit scale.
Can one of you radio eggheads explain exactly what "DBm" measures? I
think it means decibels per meter, but that still tells me nothing. Is
it "meter" as in wavelength?

On 18 Aug 2006 05:46:33 -0700, "Jim" wrote:

I would like to add an analogue signal strength meter to my Icom R75
receiver. Has anyone managed to do this, and what's involved? I'm
looking to take a 'real' indication of signal strength from the AGC
line, not just monitoring the audio output.

Thanks

This might be something you could adapt to your Icom, tho' it is made
for specific Yaesu rigs...

bob
k5qwg