From: "Scott L. Glidden" scottg@industrial-logic.com Date: Sun Apr 16, 2006 9:59am(PDT) Subject: Re: 8K Mod - Completed I did something along those lines. I removed the 4 caps which seemed to remove the 8K/Sql hiss all by itself. I temporarily snapped the logic board back on without the shield to try it :-). Seems like you don't need to move the final cap to make the mod work. I did it just because.... Also, I did start to check the caps against the service manual. Just haven't got that far with it yet... I need to dive in to expand upon LNK3D's fan mod though.... :-) ======================================================================== From: ic7000@yahoogroups.com [mailto:ic7000@yahoogroups.com] On Behalf Of Dean Gibson AE7Q Sent: Sunday, April 16, 2006 12:24 PM To: ic7000@yahoogroups.com Subject: Re: [IC-7000] 8K Mod - Completed Have you considered just trying PART of the mod, where you just remove all but the capacitor that you would otherwise move? My initial glance at the schematic suggested to me that this was going to be just a bandaid, but if your results show the tone is gone, that's good. Any ideas as to how this works? Removing bypass capacitors always seems to me to be a bad idea. Perhaps they were the source of radiation on one side of the board? -- Dean On 2006-04-16 08:08, Scott L. Glidden wrote: > I am preparing to do my second IC-7000 8K mod now... Noticing that the board rev is B6250J, my other 7000 has a B6250K. I would surmise that the service bulletin indicates B6250L onward this is fixed... The lower case "L" led me to believe that the fix started with the "i" revision. They should have used upper case letters to eliminate this confusion... > > FYI.... > Scott Glidden > KI4DMR ________________________________ > From: ic7000@yahoogroups.com [mailto:ic7000@yahoogroups.com] On Behalf > Of Scott L. Glidden > Sent: Sunday, April 16, 2006 10:52 AM > To: ic7000@yahoogroups.com > Subject: [IC-7000] 8K Mod - Completed > > Just did the 8K mod. Was VERY easy. The parts were LARGE form factor SMD devices. > > Preliminary results indicate removal of 8K whine. Squelch hiss seems to be eliminated as well....> Will feed into spectrum analyzer to see if attenuated or really eliminated. > > P.S., this mod was MUCH easier than the MARS/TVRO mod as the parts were 100x larger (Not an exaggeration!) It took more time though... > > Scott Glidden > KI4DMR ======================================================================== From: "dietmarfichter" dfichter@uwo.ca Date: Sun Apr 16, 2006 10:23am(PDT) Subject: Re: 8K Mod - Completed Hi Scott: can you shed some light on this mod as it seems to me to be some what confusing on exactly what to to. A - remove capacitor C208 and C209 from the top of the board B- remove capacitor C207 and C202 from the bottom of the board C- now use C202 and install it to the top of the board, observing that the capacitor's positive polarity is connected to the proper point. Question: where does C202 get installed on the top of the board, is it where C208 was or C209 or some where else? Dietmar VE3CG ======================================================================== From: "Scott L. Glidden" scottg@industrial-logic.com Date: Sun Apr 16, 2006 10:37am(PDT) Subject: Re: 8K Mod - Completed A & B are correct. Step C is a hack job. Double sided tape to secure, run leads to existing locations as indicated on bulletin (From Ground to + side of other cap.) Seems like you can get by without step "C", but that would be at your own risk... Have not looked at SM to see what this accomplishes... ======================================================================== From: "Scott L. Glidden" scottg@industrial-logic.com Date: Sun Apr 16, 2006 11:04am(PDT) Subject: Re: 8K Mod - Completed Also, make sure you move/re-use the larger electrolytic and not the smaller ceramic. The service update does not label these parts well.... ======================================================================== From: "Lnk3d Lnk3d" lnk3d@yahoo.com Date: Sun Apr 16, 2006 11:12am(PDT) Subject: Re: 8K Mod - Completed I belive its C207 not C202 that gets moved from the top to the bottom of the logic unit. ======================================================================== From: "Scott L. Glidden" scottg@industrial-logic.com Date: Sun Apr 16, 2006 11:18am(PDT) Subject: Re: 8K Mod - Completed C202 is a 220/6.3v, the other (c207) is a ceramic 10pf. C202 is what gets moved (The large CAP of the two). ======================================================================== From: "dietmarfichter" dfichter@uwo.ca Date: Sun Apr 16, 2006 11:50am(PDT) Subject: Re: 8K Mod - Completed Scott I am still not clear on the C202 issue. Where is the excactly location on top of the board is the location where C202 get soldered to? Is it soldered to the pads that was occupied by C207 or to the pads occupied by C209? You mention to run existing leads as indicated on the bulletin. What leads are these and where do they come from and where do they connect to? Sorry for all my questions but I do not understand where C202 gets solderd to on top of the board and what lead connections you are referring to? Dietmar VE3CG ======================================================================== From: "Lnk3d Lnk3d" lnk3d@yahoo.com Date: Sun Apr 16, 2006 0:02pm(PDT) Subject: Re: 8K Mod - Completed The service bulletin should be able to be found in the files section of this group and the IC7000mods group. 8khz fix in pdf format "Scott L. Glidden" wrote: Do you have a copy of the Service Bulletin? There is a picture of this... ======================================================================== From: "dietmarfichter" dfichter@uwo.ca Date: Sun Apr 16, 2006 7:31pm(PDT) Subject: Re: 8K Mod - Completed Yes I have it right here and now I see where it goes. Capacitor C202 is renamed (C254, a new copmponent) and is installed at the opposite side of the circuit board where C207 and C208 have been removed. Dietmar ======================================================================== ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ From: "dietmarfichter" dfichter@uwo.ca Date: Mon Apr 17, 2006 9:00am(PDT) Subject: Re: 8K Mod - Completed Correction: After close schematic examination of the 8KHz tone mod, here is what Icom has done: On the LOGIC UNIT board (B6250I): - removed capacitors C207 (10pf) and C202 (220 uf) from Q201 pin 4 - removed capacitors C208 (47uf) and C208 (47uf) from inductor L202 which connects to Q201 pins 1,2,5 and 6 - this now reduces the amount of filtering supplied to Q201 - relocated capacitor C202 (200 uf)in parallel with capacitor C711 (200 uf) for a total value of 440 uf for C711 Note: capacitor C711 filters the 3 volt line of the LOGIC UNIT therfore, more filtering capability has been added to the 3 volt line by connecting capacitor C202 in prarallel with capacitor C711 - capacitor C202 is positioned to sit on top of capacitor C524, Note: C524 has no relationship to the modification only that this is where C202 must be positioned in order to make the electrical connections to capacitor C711 with the positive end of C202 to positive end of C711, the negative end of capacitor C202 connects to the Analog ground by capacitor C614 Dietmar VE3CG ======================================================================== From: "Dean Gibson AE7Q" yahoo1@ae7q.net Date: Sun Apr 16, 2006 9:24am(PDT) Subject: Re: 8K Mod - Completed Have you considered just trying PART of the mod, where you just remove all but the capacitor that you would otherwise move? My initial glance at the schematic suggested to me that this was going to be just a bandaid, but if your results show the tone is gone, that's good. Any ideas as to how this works? Removing bypass capacitors always seems to me to be a bad idea. Perhaps they were the source of radiation on one side of the board? -- Dean ========================================================================= From: "Adam Farson" farson@shaw.ca Date: Thu Apr 27, 2006 10:40pm(PDT) Subject: Re: Questions before I buy. Hi Scott, Icom now has a service bulletin to address this issue. You should be safe with a radio manufactured after mid-March 2006. Icom service centres are applying the service bulletin to all IC-7000's sent in for warranty repair. In any event, you will not hear the 8 kHz tone on a communications-type headset or speaker designed for 300 Hz - 3 kHz. Best 73, Adam, VA7OJ/AB4OJ Owner, Yahoo! ic7000 Group -----Original Message----- From: ic7000@yahoogroups.com [mailto:ic7000@yahoogroups.com] On Behalf Of scott4957 Sent: 27 April 2006 22:25 To: ic7000@yahoogroups.com Subject: [IC-7000] Questions before I buy. I'm sorry because i know this has been talked about many times, but i was not able to get everything strait by going through past posts. Has there been any information released from icom about the 8k tone, as in how to buy one that doesnt have it LOL! Any serial number info? I am ready to buy, but to be honest a bit scared from some of the talk. Scott ============================================================================== From: "Ed Thierbach" ethierba@umich.edu Date: Wed May 3, 2006 6:21pm(PDT) Subject: Re: 7K serial numbers Hi, Scott -- try this test; it's about the only way I can hear the tone on mine. (I thought I didn't have the tone, until I tried this, and even then, it's very quiet on mine.) - Set the mode to AM - Turn the volume all the way off, The speaker should be quiet. - Turn the volume up just ONE click. The tone should appear if your radio has it. - Switch between full-off and one-click-above-full-off several times, just to see if you can hear a difference. Hopefully yours is recent enough to have been fixed. I have no regrets about buying the 7000; the two problems I've seen (TBW and 8KHz tone) are very minor for me. 73, -Ed- AB8OJ >I just received my IC-7000 today, serial 3362. To the best of my >knowledge I do not have the tone. I listened to my speaker in VHF/UHF >with the squelch closed and with a headset, I just have a low static i >guess you would call it, doesnt change with the volume, i believe this > is typical. It is nothing that I would describe as an 8k tone, and is >the same with the speaker or headset. Let me know if this sounds correct. > >Scott KC9HLN ======================================================================== From: "Frank Fox" frankcfx@yahoo.com Date: Thu May 4, 2006 8:43pm(PDT) Subject: Email to Icom America I sent to following email to Icom regarding serial numbers and fixed radios. So far they have not replied. " From: frankcfx@comcast.net Subject: IC 7000 Date: May 3, 2006 12:08:45 AM PDT To: amateur@icomamerica.com I am intending on buying an IC7000 at Dayton this year but I need to know above what serial number has the 8kc tone and the noise in the receiver at low volume been fixed. I belong to the Yahoo 7K users group and I have been aware of the problem and that there is a circuit board change that fixes the problems." Have a good day Frank WA6KGD When sending email please send to: frankcfx@bigfoot.com Thank you ======================================================================== 8khz tone or something else?... Posted by: "sv9dru" sv9dru@hotmail.com sv9dru Date: Sun Sep 24, 2006 2:02 pm (PDT) The reported white noise is indeed there at all times but partially covered by the band noise when turning the volume up. Based on similar experience with other rigs, where the problem turned out to be a mismatch of the AF output amplifier stage to the headphone impedance, I installed (after some experimentation)a 150 Ohm resistor in series with my 32 Ohm headphones. This attenuated the white noise almost completely, with minimal only attenuation of the useful AF headphone output. Now I have to listen at about 12H position of the AF volume control, but with no noise and that holds true even at lower volume settings. I have noticed no other ill effects of adding that resistor to the operation of the AF stage of the rig. 73 to all, Marinos, sv9dru / ki4gin ------------------------------------------------------------------------ In ic7000@yahoogroups.com, "tatanka01b" wrote: Same here. I didn't notice it until plugging the headphones in and trying to work some "weaker signal" stuff, but it's definately there and annoying. If you turn the AF gain all the way down, it goes away, but turn it up just a hair and there it is. No 8KHz -- just white noise. I don't notice it at all unless I'm using headphones. I got my IC-7000 back in May and it doesn't appear to have the 8KHz problem (assuming this isn't the same thing). 73, Rob (KFØRT) --------------------------------------------------------------------- --- In ic7000@yahoogroups.com, "John H Farmer" wrote: Hi all, Just unpacked my new IC 7000 and plugged it in to check for the 8khz tone problem. Well, I hear no pure 8khz tone, but I do notice that there is a prominent white noise "hiss" in the audio, present at all positions of the AF gain control and most noticeable with the RF gain wound right back. It's there through the external speaker, headphones and the rig's speaker. Is this common/normal with the IC 7000 audio or is it a problem? There's nothing at all like that coming out of my old 706. Thanks for your ideas. John. ======================================================================== 8khz tone or something else?... Posted by: "Stephen Prior" sjp@sjprior.fsnet.co.uk g4sjp Date: Sun Sep 24, 2006 2:20 pm (PDT) That¹s very useful information Marinos! I shall try that, but I notice that my headphones are already 120 ohms impedance. Thanks Stephen G4SJP PS Since my wife bought me these (expensive) headphones as a Christmas present two years ago I am committed to them! ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ======================================================================== ========================================================================