[amsat-bb] Re: Satellite Transceiver

[Edward Cole]

At 12:06 AM 4/6/2009, francesco messineo wrote:
>On 4/6/09, Edward Cole <kl7uw at acsalaska.net> wrote:
> > I guess no one considers the FT-847, yet I consider it superior rig
> >  to the venerable FT-736R.  I comes ready to interface DB-9 RS232
> >  jack.  Only issue is it is now out of production.  They show up used
> >  on e-bay at about $900-1100.
>
>I agree, it's a great satellite radio, but I always used it with
>manual tuning :-)
>However it has a lot, and I mean a lot of more or less strong birdies
>on the 2m band.
>Also the power switch fails too soon and too often if you use the
>original yaesu part.
>I also noticed that NB has almost no effect on the typical impulse
>noise that is silenced by all other NB of my other rigs. This NB
>problem has been confirmed by another friend owning the FT-847 (I
>still have to go and listen for the 2m birdies).
>
>73
>Francesco IZ8DWF

OK, good observations.

The very early production of the radio had a problem of either solder 
flux residue or improperly tightened screws on the audio board, that 
resulted in internal birdies.  Mine was a 1999 radio and I sent it 
back to Yaesu to correct that.  They cured a lot of birdies (not 
all).  Most of my birdies are eliminated with an external preamp, so 
that leads me to conclude they are generated external to the radio in 
the shack.  Placing a 50-ohm termination on the antenna connector can 
confirm this.  The Kenwood TS2000 birdies on popular satellite freq. 
is a much worse fault in my mind.

My power switch failed at about the 5th year and I simply rewired to 
the extra contacts (its a DPST switch) and has cured the problem, so 
far (note my radio is now ten years old).  The NB is a 
disappointment.  I had a FT-842 HF radio that had a terrific NB.  Why 
Yaesu couldn't copy the design is beyond me.  So if your main use is 
for a mobile radio perhaps the new 857 or 897 is better.  I don't 
have a lot ignition noise issues in my home station (occasionally, 
snow machiners), so I overlook this.

The DSP NR and filters work well.  Especially on CW.  But this is an 
area that I expect the K3 is probably much better.  I do mainly EME 
and MS so my needs are much greater for Rx performance.  For 
satellite work that is generally dealing with stronger signals, the 
FT-847 works quite fine.  I thought it was fine for AO-40!  I use it 
less for the Leos, though that will change later this year when I get 
my satellite antennas back up (also, planning to add a dual-band 
Lindenblad).  I have auto-track/tuning that was never implemented and 
expect that to make mode-LS on Leos easier (high-rate Doppler changes).

I now have 175 stations worked on 2m-EME with the FT-847.

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73, Ed - KL7UW              BP40iq, 6m - 3cm
144-EME: FT-847, mgf-1801, 4x-xp20, 8877-600w
1296-EME: DEMI-Xvtr, 0.30 dBNF, 4.9m dish, 60/300W  (not QRV)
http://www.kl7uw.com       AK VHF-Up Group
NA Rep. for DUBUS: dubususa at hotmail.com
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