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Using Sonar for NavigationSunday, October 28, 2007Q: Can a Sonar be used for Navigation? A: Sonar works much like marine radar, only in water rather than air. The transducer emits a pulse of sound energy in a direction which the operator sets, and then waits for a return of sound energy bounced off objects in its path. The electronics convert these signals into images which are then viewed by the operator. Various factors affect signal propagation through the water and the shape and density of the targets dictate how well the signals are reflected back. The harder the target, and the more nearly vertical it is, the better it reflects energy. The converse is also true. So targets which are angled away from you produce poor returns. Just like with marine radar there is a learning curve with sonar. What we know now, after just a few hours of practice, is that the basic system is quite user friendly. It looks like we are already operating at a level which gives us good functionality maybe 75% of the time. Getting to where we can efficiently use the system in difficult conditions is going to take some real world practice - just as with marine radar.
ICOM M604 as Land Base Radio StationFriday, October 26, 2007 Question:
I would like to set up my ICOM M604 VHF marine radio as a land base station. Which radios can set this way and how do I code the MMSI number?
Answer:
The ICOM M604 VHF Marine radio can be set as a land base station. You can set the MMSI number to recognize this by coding the prefix of the number with "00".
ICOM-2820H Issue with the UHFWednesday, October 24, 2007 In the November issue of QST, a reviewer commented, there was one minor issue operating the IC-2820H. This was an issue with the UHF in DV not being repeated 100% of the time. While there are a few people who have reported having this issue, it is not a wide spread problem. This is more of an idiosyncrasy of the radio and most operators would never notice if they operate the radio in a more traditional VHF on the left and UHF on the right. As announced further in the article, there is a modification available to the radio.
In addition to the issue listed above, there have been some reports of dropped communications where the radio will not transmit when the PTT is pressed on the microphone. From what we have seen, this is an intermittent issue which not everyone has or will experience. We have a firmware update that fixes this issue as well.
As these are not field installable updates, your IC-2820H’s will need to come back to the ICOM America Service department located in Bellevue, WA. These will be handled on a first come, first served basis.
Upgrade Procedure:
This will be handled as a warranty repair. Send your IC-2820H to the following: (RMA not required)
ICOM America, Inc.
Attn: Service Department (2820H upgrade)
2380 116th Ave NE
Bellevue, WA 98004
For additional ICOM VHF marine radios visit ICOM VHF Radios
What GPS can I use with my ICOM VHF radio?Monday, October 15, 2007Icom does not recommend a specific manufacturer of GPS equipment. However, most GPS equipment that meets the NMEA 0183 standard, Version 2.0 or better, will work with ICOM VHF radios. This NMEA standard uses the following 3-letter sentences:
GGA= Essential fix data with 3D location and accuracy (preferred sentence)
This includes Lat / Long, fix quality, number of satellites, horizontal dilution of position, altitude above sea level, height of geoid (mean sea level), time in seconds since last DGPS update, DGPS ID, and checksum data.
GLL= Geographic position, Lat / Long
This includes Lat / Long position, time of fix, data active or V (void) and checksum data.
RMC= NMEA recommended minimum
This includes time of fix, active or void, Lat / Long, speed over ground, track angle, date, magnetic variation, and checksum data.
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