Wednesday, December 21, 2011

My Icom IC-7600 HF Transceiver

About five months ago, my newlywed wife was nice enough to tell me that she did not have a problem with me purchasing my dream radio, the Icom IC-7600.  It sits alongside my Kenwood TS-2000X in my shack.  Now I know that many people own several HF rigs, but I do not see the point in that.  HF radios can be quite expensive.  I would rather concentrate on one or two radios in terms of the radios that I keep on hand.  I've owned a number of radios in the past from mobile radios, to HTs, to HF radios.  The IC-7600 is actually only my third HF radio.  The problem with having too many radios is that all of those radios need to be taken care of and used.  For example, firmware may need to be updated regularly, or the memories need tended to.  I don't have the time like I used to set up multiple radios.  I indicated that the IC-7600 is my third HF radio.  I've had the Kenwood the longest, but at one point I owned a Yaesu FT-897D.  The Yaesu was a decent radio, but I sold it to another ham when I thought she was ready to get on the air.  I am keeping the TS-2000X because I believe that some of its features complement the Icom.  Specifically, repeater operation is available as well as a satellite mode, and it operates on 2-meters, 70-cm, and 1.2 GHz, whereas the Icom does not.

I absolutely love the 7600.  Of course, it has the beautiful LCD screen and that screen contains the spectrum scope, but the screen contains a lot of other useful information.  However, the radio is much more than just the awesome LCD screen.  Shortly after acquiring the 7600, I participated in the IARU HF Championship, and made 23 contacts using the radio, including confirmed (with Logbook of the World) contacts with TM0HQ and NU1AW/5.  I felt that was pretty impressive given my limited operating time, and my rather limited antenna--an indoor Buddipole.  I only spent about two or three hours operating during the contest.  I had the radio on for a couple of hours on Saturday evening, and I had it on for about an hour on Sunday.  About half of my contacts were on 20-meters and the other half were on 40-meters.  I was operating in the search and pounce (S&P) mode, and most stations heard me on the first or second call.  I don't recall having that kind of success with my TS-2000X, but I may be comparing apples to oranges.  The bands did not seem as crowded for the IARU HF contest as they were during Field Day (which is the last contest I operated the TS-2000X in), and the pile-ups were not very deep for the IARU contest, or were completely non-existent.  I really am looking forward to using the 7600 during the next Field Day when the bands are typically very crowded.  I think it has a number of features on the receiving side that will make it easier for me or guest operators to pick out (more on this later) the individual stations.  For much of the operating that I do, however, the bands are not crowded at all.  I'm also looking forward to getting back on the digital modes after a two- or three-year hiatus.  In particular, I want to expand my operating skills to RTTY, and I think that the 7600 should be able to handle it quite well.  I would like to add that my first opportunity to operate split on the HF bands occurred shortly after I purchased the 7600.  I was tuning around the bands--probably on 40-meters--and ran into N4S.  N4S was the special event station commemorating the final flight of a space shuttle.  Although, I never got through, I was able to figure out how to program the 7600 to operate in split mode.  I got to hear first-hand the handful of stations that had not copied N4S stating that he was operating split, as they tried to call on N4S transmitting frequency.

Most likely the next time that I operate this radio during crowded band conditions will be the 2012 Field Day.  This radio will replace the TS-2000X during Field Day.  I may pack the Kenwood, but the Icom will be the primary radio that I use.  I'm looking forward to using several of its features that should really help pull stations out.  I suspect that it won't have any problem being heard.  Some of the features that I have used that will be helpful are:

  • Adjustable IF digital filters:  Each mode has three filters that can be quickly selected with the Filter button.  For example, on SSB, I normally am using FIL2, which has a 2.4 kHz bandwidth.  This is a decent bandwidth that allows for an intelligible signal, but at the same time, does not allow too much noise.  My SSB filter FIL1 is currently set at 1.6 kHz, and FIL3 is 3.0 kHz.  As suspected, FIL1 is a little tight and the conversations are slightly harder to copy, but noise is lessened, and the tight filter helps keep out adjacent channel interference.  FIL3 makes for easy copy on strong signals, but with weaker signals, the wider bandwidth lets in more noise, which in turn makes the signal harder to copy.  Although I'm not a CW operator, the digital IF filters can be adjusted quite tight.  The really neat thing is that each of these three selectable filters (keep in mind that these filters are implemented with digital signal processing) can be fine-tuned.  You can adjust the roll-off of the filter skirts, the bandwidth, and the roofing filter used.  The roofing filter is in the first IF stage and is the radio's first line of defense against interference from adjacent channels.  I'm assuming that my Kenwood TS-2000X has just one roofing filter and it is probably about 15 kHz wide.  A passband that wide just lets in too much signal.  With the Icom, I can choose a 15-kHz roofing filter, or a 6-, or a 3-kHz one.  I suspect that being able to select the tighter roofing filters will greatly help during the crowded band conditions of Field Day.
The filter adjustment screen on the Icom IC-7600
  • Twin passband tuning (Twin PBT):  I'm still trying to understand this feature, and I don't often use it because I don't fully understand it, but I think it allows me to adjust the lower and upper skirts of the IF filter.  So in that regard it does alter the bandwidth of the filter, which may affect the intelligibility of the signal, or the amount of noise.  The main feature of the twin passband tuning is its ability to filter out an offending signal.  For example if there is an interfering signal above the desired signal, you just adjust one of the Twin PBT controls and the undesired signal is filtered out.  I suspect that I will experiment with this feature quite a bit during Field Day, or the next contest that I participate in. 
  • The Twin Passband Tuning control
  • Noise reduction:  The noise reduction is implemented digitally and unlike the TS-2000X it is actually quite effective.  Although it is best to leave it off with strong signals, it can helpful with weaker signals.
Noise reduction and noise blanker buttons and controls
  •  1/4-Speed Tuning:  I know that this feature is available in the CW mode.  It allows more precise tuning with the main knob.
  • Auto Tune:  Again, I believe that this is strictly a CW feature, but with a push of the button during CW reception, the receiver zero-beats with the signal.
  • Auto Notch:  I've used this before, and I normally leave it turned on.  It clamps down really quick on a carrier.  People tuning up on the band during Field Day, or other contests is quite common.
  • Audio Peak Filter:  This filter is applied to the CW sidetone during reception and definitely makes hearing the Morse Code easier to hear.  I may not use some of these CW-related features that much, but guest operators at my station may.
There are plenty of other features that will help with copying stations during Field Day or another crowded-band contest.  I make every effort to understand all of the controls on a radio and maximize my use of them.  I paid quite a bit for this radio and I need to get my money's worth.  If I don't, I might as well use the TS-2000X.

The Icom IC-7600 HF/50-MHz transceiver, LDG AT-200 Pro II autotuner, and the Power Master II wattmeter
 I'll probably have more to say about this radio in the future, but I do need to get more time on the air before I write more.

73,
Ned


1 comment:

pakker transceivers said...

The IC-7600 takes a big leap from the IC-756PROIII, using the IC-7800's cutting edge digital technology. The ultra wide viewing angle display, high resolution spectrum scope and USB keyboard/USB flash drive connection greatly improves visibility and usability in practical operation.


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