[ICOM] IC756 PRO 3 PROBLEM with DSP

[Larry Dajnowski]

Will do and get back on this.
Thanks Steve.

73, Larry AJ2W

  ----- Original Message ----- 
  From: Steve N4LQ 
  To: ICOM Reflector 
  Sent: Monday, December 20, 2004 6:10 PM
  Subject: Re: [ICOM] IC756 PRO 3 PROBLEM with DSP


  Ok...Try this Larry. Go to 80m tonight. Dial in about 200hz bandwidth, cw 
  mode. Find a spot down on the low in with no activity. Use hi-fi phones or 
  wide range speaker (not the internal speaker) and listen for those high 
  pitched, crackles. They sound almost like sparks and follow the static 
  burst. They are completely out of the passband.
  Also, set your AGC to a fast speed and listen to some cw down there and tell 
  me it there isn't a hard thump on the front end of each character.
  Thanks for the help.
  Steve N4LQ
  ----- Original Message ----- 
  From: "Larry Dajnowski" <Larry at amiloan.gccoxmail.com>
  To: "ICOM Reflector" <icom at mailman.qth.net>
  Sent: Monday, December 20, 2004 6:48 PM
  Subject: Re: [ICOM] IC756 PRO 3 PROBLEM with DSP


  > Believe it or not I have seen these type spikes
  > with the IC-7800 here.  It has been internment
  > so have not been able to track down the cause.
  > Noticed on 40 meters mostly.
  >
  > 73, Larry AJ2W
  >
  >  ----- Original Message ----- 
  >  From: Steve N4LQ
  >  To: ICOM Reflector
  >  Sent: Monday, December 20, 2004 5:43 PM
  >  Subject: Re: [ICOM] IC756 PRO 3 PROBLEM with DSP
  >
  >
  >  Thanks. I tried sending this to the reflector last night but it never 
  > posted
  >  for some strange reason. Anyway, I called AES this morning and have 
  > orders
  >  to ship it in for them to evaluate. I already know they won't be able to
  >  duplicate the problem hence the reason for the jpg. I may even make a 
  > .wav
  >  file for them to QSX.
  >  No the Omni VI+ has a very wide roofing filter, 2 poles at 15khz. The
  >  problem here isn't filtering. The DSP is working but I think it is 
  > actually
  >  producing the spikes as a result of clipping. The spikes do not seem to
  >  affect the agc either because they are too fast, or because they are 
  > beyond
  >  the last agc loop.
  >  I can hear these through anything including speakers, headphones but by
  >  feeding the audio out to the PC's sound card and using hi-fi speaker, 
  > they
  >  really show up!
  >  Steve N4LQ
  >  ----- Original Message ----- 
  >  From: "Dave Meitzen" <dmeitzen at comcast.net>
  >  To: "ICOM Reflector" <icom at mailman.qth.net>
  >  Sent: Monday, December 20, 2004 6:31 PM
  >  Subject: RE: [ICOM] IC756 PRO 3 PROBLEM with DSP
  >
  >
  >  > Does the Onmi VI+ have a narrow CW roofing filter? Think heavy QRN 
  > bleed
  >  > in
  >  > to the PRO III IF? Thanks for shareing this with the group -- excellent
  >  > info. Like to know the resolution I have a Pro III :>))
  >  > Thanks
  >  > Dave
  >  >
  >  >
  >  > -----Original Message-----
  >  > From: icom-bounces at mailman.qth.net
  >  > [mailto:icom-bounces at mailman.qth.net]On Behalf Of Steve N4LQ
  >  > Sent: Monday, December 20, 2004 5:20 PM
  >  > To: ICOM Reflector
  >  > Subject: [ICOM] IC756 PRO 3 PROBLEM with DSP
  >  >
  >  >
  >  >
  >  > 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
  >  > ----
  >  > Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
  >  > Win a new Icom IC-756 PRO III and help QSL/QTH.net
  >  > Details at: http://mailman.qth.net/
  >  >
  >  > ----
  >  > Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
  >  > Win a new Icom IC-756 PRO III and help QSL/QTH.net
  >  > Details at: http://mailman.qth.net/
  >  >
  >
  >  ----
  >  Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
  >  Win a new Icom IC-756 PRO III and help QSL/QTH.net
  >  Details at: http://mailman.qth.net/
  >


  --------------------------------------------------------------------------------


  > ----
  > Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
  > Win a new Icom IC-756 PRO III and help QSL/QTH.net
  > Details at: http://mailman.qth.net/ 

  ----
  Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
  Win a new Icom IC-756 PRO III and help QSL/QTH.net
  Details at: http://mailman.qth.net/