Sounds like 146.200 is a multiple of an oscillator frequency in the display driver chipset or similar... the "modification" probably reworks the display to move the oscillator frequency of the CPU out of the ham (and maybe nearby commercial) bands? Just a guess... but sounds plausible to me, having seen a few similar types of problems in RF transmitter devices and interference with "themselves" in the past.
The public safety radio probably was on a frequency that also hit the multiple or there's a missing bypass capacitor on a data line that needs one, or similar. -- Nate Duehr n...@natetech.com On Tue, 21 Jul 2009 12:05 -0500, "John Gianotti" <w...@sbcglobal.net> wrote: As f*&(ing bizarre as this sounds, THIS IS NOT A JOKE. This is the in response to my previos post about the 92AD going blank next to a public service vehicle. I first noticed a problem with my 92-AD while working an event on July 4 (notice the date is NOT in early April). I was standing next to a police officer and had the HT in my hand and just then the officer transmitted on his commercial radio. THE DISPLAY BLANKED!!! I was most concerned. I had seen the YouTube videos where someone passes an HT over the Icom and the display blanks, but we were not that close. I called Icom a few days after to see what was going on. They had heard of the problem but could not reproduce it. I was concerned as my radio was brand new. I called ICOM again July 20 to see if there was any update (this is where it gets weird!) and in talking with the tech he asked me to perform a simple test. Here is what I had to do: 1. Tune HT to 146.200 MHz FM (I did this on the A side, don't know if this makes a difference). 2. Hold HT to the side of my head with the antenna horizontal to the ground and antenna sticking to the rear (similar to how one might hold the HT while using it but perhaps more horizontal). At this point I am looking around for the candid camera guy to jump out of my closet but I did it anyway. 3. Transmit I did so, and then looking at the display on my HT and I saw . . . NOTHING! It was blank!!! The tech said "send it in for a modification" . So, I am. According to him this is the only way they can reproduce the problem. Their theory is that in this position enough RF reflects off of one's skull and gets back into the radio to cause a problem. Standing next to a commercial radio with higher power must have had a similar effect. The radio still works when the display is blank but it is rather hard to make changes to frequency, etc. Powering off, then on restores the display. He also said they did not have the parts at the moment but I am sending mine in anyway just so I can get in the queue. Apparently the mod is not something one can do at home. Evidently they add some shielding to the CPU and also the cable that goes to the display. He asked me to send it with the antenna so I wonder if there is a problem there also (usually I don't send in the antenna with HTs I send for repair). So anyway . . . [Non-text portions of this message have been removed] References 1. http://groups.yahoo.com/group/dstar_digital/message/8264;_ylc=X3oDMTM1YmJuYmg1BF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARtc2dJZAM4MzE0BHNlYwNmdHIEc2xrA3Z0cGMEc3RpbWUDMTI0ODE5NjYwMgR0cGNJZAM4MjY0 2. http://groups.yahoo.com/group/dstar_digital/post;_ylc=X3oDMTJxaWNoaWsxBF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARtc2dJZAM4MzE0BHNlYwNmdHIEc2xrA3JwbHkEc3RpbWUDMTI0ODE5NjYwMg--?act=reply&messageNum=8314 3. http://groups.yahoo.com/group/dstar_digital/post;_ylc=X3oDMTJmN3JycGViBF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNudHBjBHN0aW1lAzEyNDgxOTY2MDI- 4. http://groups.yahoo.com/group/dstar_digital/messages;_ylc=X3oDMTJmamRvOHE4BF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNtc2dzBHN0aW1lAzEyNDgxOTY2MDI- 5. http://groups.yahoo.com/group/dstar_digital/files;_ylc=X3oDMTJndWk2OG03BF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNmaWxlcwRzdGltZQMxMjQ4MTk2NjAy 6. http://groups.yahoo.com/group/dstar_digital/photos;_ylc=X3oDMTJmODE4ZGJyBF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNwaG90BHN0aW1lAzEyNDgxOTY2MDI- 7. http://groups.yahoo.com/group/dstar_digital/links;_ylc=X3oDMTJnMWN2a2xxBF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNsaW5rcwRzdGltZQMxMjQ4MTk2NjAy 8. http://groups.yahoo.com/group/dstar_digital/database;_ylc=X3oDMTJkamQ2YnZsBF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNkYgRzdGltZQMxMjQ4MTk2NjAy 9. http://groups.yahoo.com/group/dstar_digital/polls;_ylc=X3oDMTJndWkwM2hyBF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNwb2xscwRzdGltZQMxMjQ4MTk2NjAy 10. http://groups.yahoo.com/group/dstar_digital/calendar;_ylc=X3oDMTJlMXFubmRuBF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNjYWwEc3RpbWUDMTI0ODE5NjYwMg-- 11. http://groups.yahoo.com/;_ylc=X3oDMTJlN2liYmIxBF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNnZnAEc3RpbWUDMTI0ODE5NjYwMg-- 12. http://groups.yahoo.com/group/dstar_digital/join;_ylc=X3oDMTJnaTBsM3M5BF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNzdG5ncwRzdGltZQMxMjQ4MTk2NjAy 13. mailto:dstar_digital-dig...@yahoogroups.com?subject=email%20delivery:%20Digest 14. mailto:dstar_digital-traditio...@yahoogroups.com?subject=change%20delivery%20format:%20Traditional 15. http://groups.yahoo.com/group/dstar_digital;_ylc=X3oDMTJlZmk5MWl0BF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNocGYEc3RpbWUDMTI0ODE5NjYwMg-- 16. http://docs.yahoo.com/info/terms/ 17. mailto:dstar_digital-unsubscr...@yahoogroups.com?subject= 18. http://groups.yahoo.com/group/dstar_digital/members;_ylc=X3oDMTJnZ24wcHFwBF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDdnRsBHNsawN2bWJycwRzdGltZQMxMjQ4MTk2NjAy 19. http://groups.yahoo.com/group/dstar_digital/files;_ylc=X3oDMTJobjlhdGpqBF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDdnRsBHNsawN2ZmlsZXMEc3RpbWUDMTI0ODE5NjYwMg-- 20. http://groups.yahoo.com/group/dstar_digital;_ylc=X3oDMTJmZXBqdnY2BF9TAzk3MzU5NzE0BGdycElkAzIwNTEwNTI2BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDdnRsBHNsawN2Z2hwBHN0aW1lAzEyNDgxOTY2MDI- 21. http://us.lrd.yahoo.com/_ylc=X3oDMTJudnN1aDdiBF9TAzk3MzU5NzE0BF9wAzEEZ3JwSWQDMjA1MTA1MjYEZ3Jwc3BJZAMxNzA1MDYzMTA4BHNlYwNuY21vZARzbGsDYnJhbmQEc3RpbWUDMTI0ODE5NjYwMg--;_ylg=1/SIG=11314uv3k/**http%3A//brand.yahoo.com/forgood 22. http://us.lrd.yahoo.com/_ylc=X3oDMTJwZWoyNXFiBF9TAzk3MzU5NzE0BF9wAzIEZ3JwSWQDMjA1MTA1MjYEZ3Jwc3BJZAMxNzA1MDYzMTA4BHNlYwNuY21vZARzbGsDdG9vbGJhcgRzdGltZQMxMjQ4MTk2NjAy;_ylg=1/SIG=11c6dvmk9/**http%3A//toolbar.yahoo.com/%3F.cpdl=ygrps 23. http://groups.yahoo.com/start;_ylc=X3oDMTJwdTU0aHRpBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMjA1MTA1MjYEZ3Jwc3BJZAMxNzA1MDYzMTA4BHNlYwNuY21vZARzbGsDZ3JvdXBzMgRzdGltZQMxMjQ4MTk2NjAy [Non-text portions of this message have been removed]