[ICOM] R7000 dumb question of the day

[Sheldon Daitch]

The FM broadcast band uses 75 kHz deviation as 100% modulation, so it will be very wide
for the receiver combination you are using.

Take a look at the TV station's audio, where 25 kHZ deviation is considered 100%
modulation.

The NOAA should be narrowband FM.

Sheldon

Bonddaleena at aol.com wrote:

> In a message dated 12/2/2005 2:49:53 PM Eastern  Standard Time,
> kulow at epix.net writes:
> Does the R7000 even need the preamp or  is the noise figure of the
> preamp higher than that of the R7000?  A  preamp ahead of my R7100
> actually makes things worse.
>
> 73
> Bob  WA2UEH
>
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> Your Moderator: Dick Flanagan K7VC,  icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
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>
> Thank you to all who replied... OK, here's Fridays 'dumb question /
> statement'.....
>
> I had a thought about using the 756PRO as a Panadapter for the R7000. the
> results were mixed.
> Allow me to explain.....
>
> Tuning the PRO to 10.7 Mhz and feeding it a DC BLOCKED signal from the  R7000
> IF output into the rear 1/R receive only terminal, worked perfectly while
> listening to the local NOAA broadcasts.
>
> (By the way, what the heck kind of modulation do they use? Sounds the same
> on AM or FM!)
>
> Next a visit to the airband. Man, this worked fantastic! Very weak aircraft
> signals that were just detectable (and did not move the s-meter on the R7000),
>  were now S-9 on the PRO. Note, there was NO increase in the basic noise
> level.  In other words, when the pilot quit transmitting, the s-meter on the PRO
> dropped  to zero. I was able to see different aircraft / tower signals 'pop' up
> on the  PROs display with the R7000 fixed on one frequency. So far, so good.
>
> Next, I tried the FM broadcast band. This is where things got confusing.
> Stations were basically unreadable. The PRO indicated a VERY wide and strong
> signal on the display. I tried every combination of FM, FMn, AM, Filter,
> Attenuator, etc, but I just could not make the signals sound good. It sounds as  if
> they were waaaay off frequency.
>
> I know, this is a silly combination, but the airband and NOAA results were
> SO good, I'm glad I tried it.
>
> Any thoughts as to why the FM is FUBAR???
>
>
> thanks for your patience!
>
> ron
>
> N4UE
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> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/