[R-390] OT: Other Radios You Like

[2002tii]

Cecil wrote:

>Actually I prefer ECSS to syncro and any of these radio's will do 
>that nicely.  The R-75 with the KIWA mods comes real close to the 
>R8B in all regards...I've played with both.  It's not quite the R8B 
>in the syncro department but it's real close and for a third the 
>price.  The DSP is limited but quite handy at times.

If by ECSS you mean "just listen to AM in USB or LSB mode," it 
generally works pretty well with two caveats:  first, if a station is 
off frequency by 10 Hz or more I find music sounds odd due to the 
pitch shift, and second, I feed the line outputs of my radios to an 
integrated amplifier and a good hi-fi loudspeaker, so I can readily 
hear the effects of the beat note of the local BFO and the station's 
carrier.  If the radio tunes in 10 Hz steps or finer, you should 
always be able to keep the recovered audio within 5 Hz of its 
original pitch, and if you filter the audio so it's down at least 60 
dB at 10 Hz the beat effects shouldn't be too objectionable.  But SAM 
does it without having to fuss over it.

I believe "ECSS" originally referred to detectors that extract the 
carrier by hard limiting, turning it into a square wave, then use it 
to demodulate the composite IF signal.  The Racal RA6790/GM uses a 
variation of this technique.  Good during partial fades, but not in a 
deep fade when there is no carrier at all.

I cannot share the enthusiasm for KIWA-modded R-75s.  I installed one 
kit myself, and have used two other R-75s with the KIWA synchronous 
detector mods.  In all three radios, I found the synchronous detector 
performance to be distinctly bettered by a number of other radios, 
and not even in the same league as the R8B.  I was able to do better 
with my own mods, but not well enough to justify keeping the 
radio.  The Icom also shares with some Kenwoods a "sound" I can't 
quite put my finger on -- it gives the impression of excessive noise 
that intrudes even when band noise is higher than the apparent high 
internal noise.  I get this image that I'm tuning around in a rather 
dense fog, even when band noise is low.  It generally pulls readable 
signals out, but I really don't like the effect.

Best regards,

Don