2016-04-22

IC-7300 First Impressions.

Having worked with a 7600, and also with a 7100, for a while, and being very happy with that, I reacted on the very favourable  reviews of the new IC-7300, and I now have one.

The IC-7300 is the first Amateur radio station by the big 3 Japanese manufactures, being a direct sampling, stand alone SDR radio. I have been looking through various reviews by amateurs having the transceiver before me, and I have not seen *any* negative reviews. Minor nitpicks, but absolutely nothing serious. Given the price point of this radio it looked like a very favourable purchase, despite it being this early in the life time of the transceiver.
I emptied the purse and got one.

First of all the noticeable thing that the 7600 does, and the 7300 does not : Dual reception. This is something that I have not yet used much, so I am probably not going to miss it much.

Then a few things that the 7300 does, that the 7600 does not :

1) 70MHz. This was high on my wish list for a multimode transceiver. Yes, the IC-7100 does 4m (and 2m/70cm), but that one does not have the *very practical* waterfall spectrum display.

2) The built-in antenna tuner (OK, matching circuit) has an "Emergency mode" where, at the price of reduced output power (50%) the tuning range is considerably increased. This can be very convenient with portable operation, where cables are usually shorter, and therefore less lossy.

3) The spectrum scope : The waterfall and spectrum scope is *very fast*, it is possible to "read" CW at slow to moderate speeds, and the signals look much cleaner (narrower) than on the 7600.

4) 472kHz : The radio has been opened for the full TX range, since I want to be able to work on the 5MHz band, and I tested, and found that it actually has some RF output on 472MHz. Something that I never detected on my 7600, or any other radio I have owned. It look like I should try to make some kind of antenna for this band, and for 160m, although, given the size of my garden, and the modest antenna height possible, my expectations are not very high. Thinking of it, I should probably check the output on 472 for spectral purity, I might need a (low pass) filter before I start transmitting serious power on the band.

Operation of the 7300 is in between the 7100 and the 7600. It has a few more dedicated buttons than the 7100 (which uses the touch display extensively), and some of the 7600 dedicated buttons and controls have been squeezed into a multi-function knob and the use of the touch screen. All in all, having used it a few days, my only complaint is that the band switching and the band stacking registers need double the operations when compared to the 7600 (but same as the 7100).

Modulation quality is excellent, right out of the box, I have yet to make any adjustments. I might use the tone controls a bit, but, working mostly CW, I have not yet done much about that.

All in all, the operation with the 7300 is easy, although I have only scratched the surface of its possibilities. I am very happy using this in my "living room shack".
The price is less than half the price of the 7600, and still lower than that of the 7100. Impressive !

Now I need more antennas ;)

I believe this transceiver is only the first of many direct sampling stand-alone radios. Icom has impressed me quite a bit with this one. Come on, Yaesu, Kenwood and others ...



2016-04-17

Sporadic E Season is Starting, Slowly, on 10m.

Yesterday and today showed Sporadic E spots on 10m WSPR.

Spots from Italy and the UK, as well as a few others popped up. The list for the last 24 hours looks like this :

17 spots:
TimestampCallMHzSNRDriftGridPwrReporterRGridkmaz
 2016-04-17 14:36  G3XBM  28.126125  -27  0  JO02dg  2  OZ9QV  JO65cp  864  60 
 2016-04-17 14:32  GM4FVM  28.126087  -11  -1  IO85wu  5  OZ9QV  JO65cp  896  86 
 2016-04-17 14:32  G0VUH  28.126040  +4  0  IO93ji  5  OZ9QV  JO65cp  901  68 
 2016-04-17 14:12  G6SSN  28.126141  -25  0  IO92tt  0.2  OZ9QV  JO65cp  875  64 
 2016-04-17 14:10  GM1MSS  28.126138  -21  4  IO85  0.2  OZ9QV  JO65cp  957  83 
 2016-04-17 14:06  DL4MFC  28.126129  -6  0  JN58qb  2  OZ9QV  JO65cp  845  4 
 2016-04-17 13:58  G4CUI  28.126069  -6  0  IO93fi  5  OZ9QV  JO65cp  922  68 
 2016-04-17 13:32  GM4EAU  28.126088  -15  -4  IO85  0.1  OZ9QV  JO65cp  957  83 
 2016-04-17 13:28  G3YFG  28.126086  -24  -1  IO83tu  0.2  OZ9QV  JO65cp  955  72 
 2016-04-17 12:42  UT7GH  28.126133  -14  0  KN66hq  5  OZ9QV  JO65cp  1727  313 
 2016-04-17 12:18  G4HBA  28.126073  -13  -1  IO93fn  5  OZ9QV  JO65cp  914  70 
 2016-04-17 11:44  IK1WVQ  28.126067  -25  0  JN44  0.5  OZ9QV  JO65cp  1263  9 
 2016-04-17 11:32  G0HVQ  28.126117  -13  -3  IO81ux  5  OZ9QV  JO65cp  1033  61 
 2016-04-17 11:30  G8VDQ  28.126035  -26  0  IO91um  5  OZ9QV  JO65cp  942  56 
 2016-04-16 18:54  PU3WSF  28.126089  -16  -1  GG40kb  5  OZ9QV  JO65cp  11242  31 
 2016-04-16 17:46  OZ3GD  28.126097  -7  0  JO65bk  5  OZ9QV  JO65cp  24  13 
 2016-04-16 17:06  OZ7IT  28.126138  -4  0  JO65df  5  OZ9QV  JO65cp  47  354
I noticed that there were reports of 6m opening with Es, as well. I am looking forward to se 6 and 4m open to my area, though the main emphasis will probably be on 10m this year.
One further step would be a transmit antenna for the WSPR transceiver. DCTL antenna, or a very short whip/dipole should do for this purpose.

An antenna, mainly for reception on 10/6/4 (including Russian TV carriers on 49.75MHz and FM transmitters in the Russian 66 - 73 MHz band) will probably get mounted soon, just a multi-wire dipole at the gable of the (big) shed.
More antennas are planned, more about that later.

2016-04-14

Small indications of ES, and a small solar flare

10m sporadic E is slowly warming up. The last few days have seen a single spot on several days, of European stations, and today spots from Italy, the Chech Republic and France have appeared on my WSPR screen. It will be interesting to see what happens in the next few days.
Until now my 10m WSPR activity has been receive only, but I think it is time to build or mount an antenna capable of transmitting, too. I gather that there are probably other stations also just listening, and listening to the other fellow listening is a poor way of monitoring propagation, yes, I know ...
I have been thinking of using a 10m version of the DCTL antenna, not 100% efficient, but the receive sensitivity can be improved with a preamp, and it is, after all, possible to send a bit more TX power into the antenna, in order to compensate for losses in the antenna. After all, the band noise on 10m is quite high, compared to a modern receiver preamp's sensitivity.

A small surprise today was a small solar flare. It was only a C2 flare as reported on Solarham , but I noticed the increased noise level on my 10m receiver, and a bit of waves of noise on the band, audible, and also visible on the spectrum waterfall display. Nice to notice such a small flare in the HF radio spectrum. Maybe I should make myself a solar noise monitoring system, monitoring a few different frequencies in the 20-80MHZ range. All that is needed is a few direct conversion receivers and a wideband antenna, like my active receiver antenna.

2016-04-12

Spring Time and Antennas.

It has been a little while.

I have purchased a Cushcraft R6000 antenna, and it has to be assembled and set up this spring. This should enable me to work with a decent efficiency on all bands between 6m and 20m (yes, also 12 and 17m). The antenna is a shortened end-fed half wave antenna, so the current maximum should be a bit higher above ground than for a quarter wave ground plane.

The other day I had a little surprise. My HF dipole does not work at all on 10MHz. I decided to see if my 10m half wave vertical (without radials, of course) would match on 30m, and with the built-in tuner in the radio it turns out that it works much better than the dipole.
Now, since the antenna is too short, even for a quarter wave on 30m, and the impedance transformer at the bottom of the antenna is a *step-down* transformer, is is quite surprising that the unmodified antenna works on 30m.
I have been working a bit with this antenna, and DX is *very* difficult - no surprise there.
I suspect that the cable shield does its part of radiating my 30m signal, so who knows how the radiation pattern looks ? ...
I would like to work on a more regular basis on 30m, so I have been thinking of a few options :
1) Making a simple ground plane with a few radials above ground, a decent antenna
2) Making a half wave antenna, using a 15m long telescopic fibre-glass mast. This has the advantage that the current maximum goes up to 7.5m, and that the counterpoise only needs to be rudimentary, due to the high impedance of the antenna - this should prove an excellent antenna for 30m
3) Using the 15m mast with 3 wires for quarter wave resonators for 30, 40 and 60m. A little less efficient on 30m, but with the bonus of 40 and 60m operation - and a decent counterpoise is needed - a few radials for 30m and one or two for the 40 and 60m bands will have to do at my place.
4) Using the 15m mast with a single wire, then using a match box (e.g. an auto-tuner) and radials. This could be made to work on all bands form 30m to 80m, possibly, with low efficiency, on 160m.

All has its ups and downs - I may try several of the options over time.

Then there is 4m and 6m.
My only antenna till now is a 70cm/2m/6m vertical is off resonance, and will have to be fixed or replaced. Also, the cable is *very old* and should probably be replaced. For 4m I am considering an end fed half wave antenna - yes, I like those.

Right now I am looking forward to the summer sporadic E skip season, I intend to focus on 4, 6, and 10m. this year, and should I be able to work Es on 2m with the vertical, that would be a welcome bonus.