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Re: 123MHz on FT-847



on 3/16/03 4:06 AM, Edward R. Cole at al7eb@ptialaska.net wrote:

> Interesting comparison.  I haven't listened using my FT-817 so do not know
> how it compares with my FT-847 at 123 MHz, but with the int. preamp off my
> FT-847 noise floor is about s=0.5 when fed by my MKU-232A2 preamp into a
> stock Drake-2880 (2401/123).  max beacon runs s=5.5.  I see no problem at
> 123 with my FT-847.  Perhaps yours is in need of alignment?

Hi Ed,

I'm beginning to wonder if there isn't a problem with my 847.  But then
let's run some numbers real quick.  There is where I'm having difficulty.

If I turn my preamp off on my 847, I get very similar results to you.  So
maybe I'm not too far off.  Admitedly, I'm going to have to make some
assumptions here so this is not necessarily accurate:

Let's assume on the FT-847 and on the FT-817 that each S unit is only 2 dB.
If your range is 0.5 to 5.5, then you have a 10 dB total dynamic range on
your 847.  This is similar to what I see.  On the other hand, what I see on
the 817 is a range of 0 to 8.  This would equate to a 16 dB dynamic range.

The only conclusions that I can think of that would say that the 2 radios
still perform equally are:

1.) There is a drastic difference between the two S-meters on each radio

or

2.) The S-meters are not anywhere near linear and actually do not represent
a constant "dB" change.

I'll admit each of these is very possible.  I've been wanting to calibrate
my S-meters on each rig so perhaps this is a good excuse to do so.  I know
my conclusions here are unscientific at best.  And it seems to me that the
way signals sound on the 847 just is not all that good.  But perhaps my
hearing is biased because of the results I visually see on the meters....

73,

Jon
NA9D
-------------------------------------
Jon Ogden
NA9D (ex: KE9NA)

Citizen of the People's Democratic Republik of Illinois

Life Member: ARRL, NRA
Member:  AMSAT, DXCC

http://www.qsl.net/na9d   <- Updated on 1/22/03!!!

"A life lived in fear is a life half lived."


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