[ICOM] R7000 dumb question of the day

[Bonddaleena at aol.com]

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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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