I have gone from a Pro to ProII and now a pair of ProIII's.
There was no doubt the original Pro had a strong very annoying pop with
strong adjacent CW stations. With the ProIII if you engage the soft shoulder
filter shape the pop is down significantly from the original Pro, only when
comparing the same adjacent interference on both rigs. However, remember
this is a IF DSP based radio so there are trade offs. If you wish for the
old fashion 'quality' CW tones then the mechanical filter rigs are sure the
way the to go. If you run with the big boys in a contest with congested
bands then your trade off is tone vs. bandwidth.
Me, in contesting, I use an pair of external audio filters that have made
the pops almost non-existent and live with the 'tinny' sound. For rag
chewing, filters at maximum bandwidth and enjoy a favourable sound.
Eric - VE3GSI
> -----Original Message-----
> From: Tony
> Sent: February 27, 2008 1:03 AM
> Subject: [TowerTalk] Off-topic -- Pro III CW issues
> Apologies for the off-topic subject -- please reply direct.
> The original Icom 756 Pro receiver had an anoying popping sound that
> would show up at the start of each morse element when listening to
> strong CW signals.
> The 'pop' was mentioned in the QST product review in 2000 as as
> "characteristic of direct conversion receviers employing
> audio-based AGC
> systesms" and "the pro has a habit of introducing pops on the make of
> each CW element".
> Before purchasing an Icom 756 Pro III, I was told (by Icom) that the
> 'popping' issue was addressed, but that's not the case. The problem
> still exists and is especially obvious with fast AGC
> settings. It's not
> too bad with the internal speaker, but it certainly shows up with
> headphones and some external speakers.
> Suggestions appreciated...
> Tony -K2MO
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