[ICOM] IC756 PRO 3 PROBLEM with DSP

[Steve N4LQ]

Subject: IC756 PRO 3 PROBLEM with DSP


I received a new PRO-3 last Thursday from AES. The DSP has a problem especially when using the NR. The problems is distortion products resulting in large noise spikes, far outside the bandwidth setting. 
Last night I made some recordings using Spectrogram. Band, 80m, Conditions- Heavy QRN, BW-250hz, NR ON, DSP CW-soft. I recorded both  the OMNI VI+ and PRO-3 connected to the same antenna. Please see the scope patterns at this link:

www.webham.com/PRO3.jpg

When listening through wide range headphones which are plugged directly into the PRO3, the spikes are very annoying and make copy almost impossible. Turning off the NR helps some. There is certainly a problem with the DSP. At this time I do not know if it's just my rig or an engineering problem.

Note: Before this, I owned a PRO2 for 2 years so I am quiet familar with how the radio SHOULD function.

I am contacting AES tomorrow. Hopefully they will provide an exchange. 

Stay tuned for further developments.


Steve N4LQ

IC756PROIII
IC-756PRO3
IC756 PRO 3