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Re: TH-D7A(G) vs W32-A for Easy Sats?



Emily Clarke wrote:
> At 02:41 PM 12/9/2005, you wrote:
> 
>> I prefer the D7 over the Icom mainly because it has a slightly better 
>> receiver
> 
> 
> This is a surprising statement = the sensitivity for the W32A is 0.16uV 
> and the sensitivity for the D7A is 0.18uV.  So I'm not sure on why you 
> would say the D7A has a better receiver?

In reference to what?  12dB SINAD?  Start of signal reception?  Some 
other agreed-upon measurement point?  And are both the VHF and UHF 
reception numbers the same?  I doubt that.

Are these measured by you, or "as published by the manufacturer"?

(Never trust the guy trying to sell you something with performance 
numbers.  Always measure yourself or use a trusted 3rd party's 
measurements.)

Just being a pest to make sure these numbers have some basis in reality...

By the way, anyone who lives where a VHF or UHF receiver with that kind 
of sensitivity isn't blasted by other local transmitters and the general 
noise of a city -- I'm jealous.  ;-)

I'd be hard-pressed (no EME guys allowed to make wisecracks here...) to 
hear the difference between a receiver capable of 0.16uV and 0.18uV when 
operating.

Receiver sensitivity measurements on a bench are a nice starting point, 
but only a good USEABLE receiver sensitivity test with the antennas 
installed, and then injecting a known weak signal to overcome the noise 
level, is really all that useful for the real-world, after the radio's 
installed and ready to go.

It also gives you a starting point to decide if that fancy pre-amp you 
just bought is amplifying real signal, or just raising your noise floor 
excessively also.

Seeing at what point a weak signal overcomes your local noise floor -- 
now THAT's useful information!

The receiver technically may be able to receive lower than that, but 
you'll never know it when operating that station!

And 0.02uV?  C'mon.. that's getting into the realm of "measurable, but 
not relevant to real-world operation".

Nate WY0X
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