As one of the victims of the smoking exit of my driver board, I should point out that ICOM France had acknowledged that there were a batch of IC7000's with a bad transistor, that, when it went, took the driver board with it. For a while, ICOM USA was replacing driver boards under warranty without replacing the bad transistor. Hence the cases of multiple driver board breakdowns. Since my repair in France, I have been using the IC7000 regularly for almost two years with no further problem.
73, Dick F4WBK/WO1I
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--- In ic7000@..., "Steve W3AHL" <w3ahl@...> wrote:
It's unfortunate that so much misinformation is available on forums, resulting in more problems, rather than more solutions. I apologize for repeating the following information that I posted not long ago, so feel free to delete this post if you feel that good grounding is pointless....
Communication system grounding practices are well understood by most commercial installers, resulting in good protection of radio equipment from various electrical discharge conditions (direct lightning strikes, nearby strikes to power & communication lines, etc.). These same practices, scaled down a little for most ham sites, will prevent many failures attributed to "radio design problems".
The statement that the 7K fails because it is connected to an earth ground and should either not be grounded or only grounded to the electrical "mains" ground violates fundamental system grounding principles.
1. All antenna feed lines must have a good quality lightning suppressor connected to a "good" grounding system near the "entry point" to the building.
2. Antennas located on towers or similar structures should have the coaxial feed line shields bonded to the tower at the top and bottom of the structures. Feed lines should always exit the tower at or below ground level. Additional surge suppressors at the base of the tower may be justified if the the tower is over 100', on a hill, in an area with high lightning activity, etc.
3. The tower structure must be grounded to multiple ground rods interconnected by #4-6 buried solid bare copper wire radials.
4. The tower grounding system, entry point grounding system and electrical panel grounding system must all be interconnected, usually with a minimum of #6 copper wire, although larger conductors are preferred. This helps maintain all grounds at approximately the same potential if a high current surge occurs at any of the three main grounding areas.
5. The radio room should have a low-impedance ground bus tied to the entry point grounding system. All equipment chassis connected to incoming lines (feed lines, telephone, data, satellite, cable TV, etc.) should be directly connected to the radio room ground bus, where possible. This is not for RF grounding, but rather an additional layer of protection for voltage surges that can propagate inside the structure (due to a non-zero impedance external grounding system).
6. Additional surge protectors should be installed on all electrical and communication lines entering the structure. These surge protectors are bonded to the other grounding systems to maintain an equipotential ground reference.
If you install any radio system that doesn't comply with the above general guidelines, the probablity of eventual failure due to electrical overstress (a "zap") is increased significantly. Proper grounding systems typically cost less than 10-20% of your investment in the radios, computers, antennas, towers, rotators, etc., if you install it yourself.
So, please ignore suggestions that 7K's should not be grounded, or only grounded to the electrial panel ground or only grounded to a ground rod outside the shack.
I have been at many hams' homes, helping then understand why they have various problems. Very few follow good installation practices for electrical power, antenna installation, feed line termination, testing and maintenance of their system, lightning protection, etc.
And many of their equipment problems and failures are a direct result of not having a basic understanding of how to install and use their equipment.
The ham community does a poor job of elmering new hams anymore. Many radio clubs don't provide the exposure to technical and installation information available from their more knowledgeable members. And many new hams don't seek out advice before setting up a station. Memorizing the license study guide and passing the exam is often the extent of some ham's technical knowledge.
While not all equipment failure is the result of poor installation practices and operator error, my experience has been that probably 50% could be attributed to that.
There is no need to only run your TX power at 30% for fear of smoking your 7K. Mine have been in fairly heavy use (and sometimes abuse) for over 6 years for one and 3 years for the other. I had a UHF PA fail after about 6 months, that may have been due to my error in connecting the wrong mobile antenna feed line to the ANT2 connector (more than once) when swapping the radio in and out of the mobile.
Operators that report multiple driver failures in a year or two, need to look beyond the 7K itself, perhaps. I know a lot of 7K owners and just don't see that kind of failure rate.
Steve, W3AHL
--- In ic7000@..., "Oshb5" <andy@> wrote:
Hi All
Iv not had my 7K long and its only set at %30 power output so hopefully it will not smoke. But Iv even heard of others smoking just set on receive I am the third owner of the unit So it may have been done before hand Im not sure If they used it much or hardly at all I dont use it hardly but now am wondering if the smoke is a worry?? so consciously not using it in case?
Also I was advised on a forum to disconnect the earth like you described Iv also been thinking about taking it to the earth on the mains wiring to get the best earth as Im running a long wire so could need the earth to help the antenna could I not?
Can I ask Icom are researching this What happens if they come up with a fix will they have all the radios back in and fix them even if out of warranty. Because just looking for a fix to me makes it sound like its their fault?
regs Os.
--- In ic7000@..., "Marc Hillman" <vk3ohm@> wrote:
I have smoked three brand new IC-7000 (driver boards) within a few weeks of purchase. If the unit has been in Rx for a while, and smokes for no reason, it is probably the earth. It is an uncommon, but accepted by Icom problem, that if you have an IC-7000 connected to a really bad earth, i.e. it's more of an aerial than and earth, then this happens. Icom are researching the problem, but don't have a fix yet.
Either
a. Disconnect the earth entirely, or
b. Connect to mains earth, or
c. Fix your earth
I elected option b and have been trouble free for 6 months.
