Saturday 15 December 2018

IC9700 thoughts

Apologies for no posts for a few days, but I’m recovering from a rather nasty viral infection, caught last weekend, and which is only slowly responding to doctor’s orders! I’ve not been anywhere near the shack for almost a week and the time has allowed me to reflect on what I expect of the new ICOM 9700. 

Two and a half years ago I purchased an IC7300, more in hope than expectation of a good, useable, design. I was most pleasantly surprised at how good it is, especially as a K3 with all the bells and whistles owner and user. The IC7300 turned out to be, for me as very part time HF operator, a far more user friendly rig than the K3. Undoubtedly the K3 scores well on many points, and although I know personally that it has much VHF and microwaver input to increase it’s appeal to upper bands amateurs. Its range of transverter interfaces is unmatched, with easy (too easy?) access to a wide range of  level, frequency and offset adjustments and a superb IF interface facility.  But that P3 is nothing short of useless for anything serious and although I have installed the SVGA interface, I don’t see any significant overall improvement compared to using an SDR-IQ as the ‘go to’ spectrum and waterfall display and it has the advantage of ‘Continuum Noise’ measurement when used with Spectravue which the P3 doesn’t offer. If you haven’t used this measurement you can’t be a serious radio ham!!, we won’t mention the awful encoder interface on the P3 beyond could Elecraft chosen anything worse? Yes, there are ways round all this, but I want a self contained radio that doesn’t need a PC/laptop and a 27inch monitor on my bench just to see that weak signal in the noise.
The Internal 144MHz transverter is poor. I will leave it at that. A well-known UK amateur had a far more descriptive suggestion.

No, the IC7300 is not a panacea. The German transverter interface had a major problem that was slow to be acknowledged. I’m told it’s now been sorted. I’ve not revisited it. I reverted to the good old power attenuator solution.

Given all this, why am I looking at the IC9700?

First  let me say that I have some reservations about the design and these will only be resolved once I manage to get one on my bench. 
Living as I do on the east coast, I have a few unusual conditions to contend with. On 23cm I am very close (<5km) to the GB3MHZ Martlesham 23cm beacon. When I borrowed an IC910X, some years back, and first tried it on 23cm, it was completely unusable. The phase noise from the IC910 Lo (VFO) was so poor that reciprocal mixing from the beacon was apparent 700kHz away in the usual DX frequency area of the band.
When the North Sea path opens up Belgian (in particular) radar can be rather strong. Most rigs have a noise blanker than can cope with the noise. It is not like car engine ignition or an electric fence. The radar beam sweeps past and produces multiple pulses and these are very often accompanied by forward reflections from objects out to sea (and maybe reflections from inland objects) that add together to sound like a buzz. Some rigs (like the TS2000x) can cope rather well with this, other fail miserably. This will be a severe test for the IC9700.

Another problem is likely to be on 144MHz where I have a number of well placed, adequately ‘endowed’ EME stations in the surrounding counties. The K3, with an Anglian transverter, copes quite well. The TS2000X (which always needed a masthead preamp) did not. 

So, what am I waiting for?

I’ve read (re-read) the specs, asked questions of the manufacturer’s representatives at Dayton, Friedrichshafen and in the UK and not (no surprise there then) gotten the answers I wanted. So now I have decide that the price is just about affordable to buy one and see how well it copes at this QTH.
I believe I have the experience from being the designer of many transverters for all of these bands to make sound judgement on performance and to write up my experiences on my blog.

I’ve paid my deposit and now I wait..........

Sam






2 comments:

  1. Will be interested to hear how it works out for you. A few local contesters have them on order up this way. So should get some fairly fast feedback on how it works in that environment.

    I'm waiting to see if there is any issues and if Icom address them before modernising the shack with one.

    Would be nice to spend more time operating than repairing old radios.

    Best Regards, Stuart

    ReplyDelete
  2. Hi Sam ,

    I had a discussion with a German specialist last w.e during our V/U/SHF convention.
    He had measured the 7300 before and found the composite tx noise being bad. His measurement was confirmed by other friends.
    He measured lately the 9700 and told me the TX composite noise is much better , but not as good as we would need
    73
    Dom/F6DRO

    ReplyDelete