Re: Received signal question


Steve W3AHL
 

It sounds like your radio has a problem. The 7K's I've tested all meet or exceed Icom's spec, which is comparable to similar radios. On HF the S-meter is calibrated for S9= 50 microvolts (-73 dBm) with the pre-amp OFF, which is the IARU recommmendation. On VHF the S-meter S9= 6 microvolts (-91 dBm) with the pre-amp ON, which is close the the IARU spec of -93 dBm.

S-meter readings vary a lot among manufacturers and models. For example see:

http://groups.yahoo.com/group/ic7000/message/27002

The 7K measurements given there were for a different radio that had been adjusted some and are for FM mode (the values above are a factory calibrated 7K in SSB mode).

As to why the radio seems deaf, I would suggest you find a local ham or service shop that has a calibrated signal generator or service monitor and verify the sensitivity first. Or do a side-by-side comparison with another radio on the same antenna.

If it is deaf on "all bands" (meaning HF, VHF & UHF), then possibly lightning zapped your site and damaged the front end circuits. Since HF and VHF/UHF are totally separate circuits, it is unlikely for a common component failure to affect both. Proper grounding and lightning suppression usually prevent such damage, in my experience.

If only HF is bad, then it could still be lightning damage, or just a random failure in the RX front end circuit. Another problem I saw once is one ham had solder balls on the tip of the PL-259 connectors, which spread the female contacts inside the radio's connector. When he changed to a jumper without the solder ball, the connection was poor, resulting in intermittent contact.

The radio probably needs to visit an Icom Service Center. There aren't any magic adjustments to you can make.

Note: To start a new topic, click on the Post button in the upper left side menu, rather than hijacking a thread about a different topic.


--- In ic7000@yahoogroups.com, "DougH" <specialq.que@...> wrote:

Hello,

Have 7K where signal strength meter always shows a very low reading and the
RX audio is also very low - seems deaf. The problem is evident on all bands.
Been tested on several antennas and at different locations with same
behaviour displayed despite several resets.

The fact that all bands are affected is concerning - has anyone seen
anything similar or be able to suggest what might be at fault.

Regrads,
Doug - GM7SVK
..snip..

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