Showing posts with label V/UHF. Show all posts
Showing posts with label V/UHF. Show all posts

Wednesday, 25 September 2013

2m - a Band of Two Parts

Like the incoming tide washing away a beautifully constructed and elegant sandcastle, bit by bit, this week’s tropospheric ducting crumbled away with equal inevitability.

At its height, this radio superhighway, formed by different layers of air density and temperature, ‘hotwired’ parts of Europe together on 2m and above like they were connected with RG45 coax itself.

The opening was heralded, accurately, by William Hepburn’s tropospheric ducting forecast (see http://www.dxinfocentre.com/). This site also explains various propagation modes on VHF and above, in a clear and informative manner.

Let me tell you a little about my 2m station here in North Wales. I have a lovely Icom IC-910HX and my antenna is an HB9CV. Yes, you heard right, a peashooter. Two small elements phased together and put up on a pole on the side of the house. You see, I’m starting modestly because our national culture demands that we never do things the easy way. Added to the equation of difficulty, I have a range of 3000ft mountains not too far away from me. Did I mention the HB9CV was fixed? It points plaintively towards the south-east in cold, metallic expectation of flux. It points towards the long, golden beaches of the low countries, the rolling fields of northern France, the great cities of Western Europe and finally, the snow-capped Alps and beyond. But it also has a ‘heart’, a cardiod footprint in fact. The characteristics of the HB9CV trade-off a modest gain with quite a wide beam-width, with a sharp null behind it, giving it its heart shape.

The humble HB9'
You need good hearing. The receive gain is lacking for weak-signal work, but work it does. And this week I worked a station (OE2XRM) in Salzburg, Austria. 5,5 both ways! The pure magic of hearing a man who may be wearing lederhosen over what is normally a line-of-sight form of communication, is thrilling! A couple of stations from Bavaria followed and I was then content to listen as the chatter of stations from France and the Netherlands filled the band.

Later in the afternoon, fuelled by electromagnetic excitement, I ventured onto a local hill (178m/584ft.) with my lovely FT-817 and a 9-element 2m yagi. I also took along a 70cm yagi for fun.

A quick scan through the beacons bought in HB9HB in Switzerland! The Alps, the chocolate and cuckoo clocks! Unleashing my 5W on Europe didn’t produce much, unfortunately – just a couple of cheery calls from the UK, so I thought I’d swing the beam round to Spain. Now, the DX cluster was not showing any propagation in this direction and I wasn’t hearing any of the beacons on the north Spanish coast. But suddenly, out of nowhere, and at 5,9+, came a signal booming in. Danny, EB1LA, on the northern Spanish coast was stunned to hear me at 5,9 with my humble five Watts. What a result! I can only conclude that the beacons may have been situated too high to ‘tap in’ to the duct. How many people in the UK and Ireland must have been beaming away from Spain that day having assumed that no beacon = no path? I wonder. A quick scan on 70cm revealed no traffic, but I did receive the Netherlands beacon PI7CIS. Quite a trip for UHF.

My hilltop station
The two metre band can be sublime, but comes in two parts. The FM part of it is like an amateur ‘pub’. It seems the place where people gather in the evening to discuss their day and engage in chat (For example, one QSO I heard earlier this year was despairingly on the subject of “my favourite biscuits”). But the lower portion of the band has the elegance and sophistication of a Grand Cru. It’s as if it’s optimised in terms of antenna size, required power and number of users to give you a fighting chance of achieving glory in the aether. And I did.

Postscript 03 Oct. 2013: Just read EI3KD's excellent blog about this tropo opening. It coincidentally contains an audio capture of the end of my QSO with OE2XRM! Recommended reading (and listening).

Tuesday, 8 May 2012

Icom IC-E92D – Why This Is My ‘Staple’ Handheld

Every ham has a handheld in their collection of transceivers. I have one normal rig in my collection of handhelds. Nearly all the equipment I have can be held in my hand, chucked in the car, operated ‘portable’ or temporarily connected at home. It’s the capability that would suit a cold war double agent who has to move between a series of safe-houses at short notice. Everything I have, I can pick up and run with. Just as well I don’t have an HF vertical that looks like a porcupine then.

I’ve had my beloved Icom IC-E92D for a couple of years now and I spend more time talking though this than any other piece of equipment. Two years ago there was no DV (Digital Voice) or D-STAR activity in my area, but I wanted a dual band handheld that would be, to some extent, future-proof.

And before the rival Yaesu C4FM digital system is mooted, let me say that D-STAR is so firmly established, that a lot of infrastructure would be needed to better the existing system. Great advances have been made lately with the advent of the German DV-RPTR (‘DV Repeater’) boards as well as the new DCS reflectors. Having said that, I’m always keen to try any new digital modes. 

I’m not going to dwell heavily on specification and features because this is not a newly launched product – there are plenty of excellent resources and reviews already available. But here are some things that have pleased me about both the radio and the technology behind it.

Icom IC-E92D
Let’s put the digital stuff to one side for the time being. I think the E92D is just an excellent FM transceiver in its own right. Its construction is solid and feels good in the hand. Used outdoors, it’s comforting to know that it’s waterproof. I live in Wales, after all. The send/receive audio quality is very good in all modes and the microphone doesn’t suffer from the aforementioned weather-proofing that blights some other units. It seems XYL’s sewing kits have been raided worldwide for needles to pierce microphone membranes.

I love using low power when I can. In DV mode you either get a R5 copy or rapidly nothing. Why not see how low you can go? The E92D will go down to 100mW and oddly enough I use this more than any other power setting. It’s also all you need for your home D-STAR hotspot, isn’t it? A group of three of us had a 2m net with a distance of 20 miles between the furthest stations. We all used DV mode and 100mW (external antennas, of course) for a full lock and quality audio output. Compare this with the FM mindset of achieving ‘full quietening’ in many local nets. Admit it - a small swell of pride is taken in how many dB’s ‘over’ are registered. With DV it is how few. Back to the E92D: If things get marginal and stressed then the next increments are 500mW, 1W and 2.5W. Unleash the whole 5W if it’s a national holiday or you’re feeling reckless. In common with many handheld owners, I also have an aftermarket antenna to add a little more gain when needed.

Built for the outdoor life - with HM-175
GPS Speaker-Mic 
I have, and recommend, the RS232C remote cable and bundled programming software. There are enough people now who have kindly uploaded their files (called .icf files) to the internet with repeater and node settings for entire countries. You can enter or edit data manually from the front panel, but as with most radios a computer will save you time you can otherwise spend chatting idly. Seeing how the channels and banks are organised on-screen helps you properly exploit the memory capacity. Apart from the usual, I have also stored AMSAT, marine band, PMR and SWL channels. I travel a lot so it’s good to have repeaters stored by region too.

Dislikes? Only a couple and they’re not going to jaundice my high regard for this pleasure-giving, grown-up gadget. Most E92D owners acknowledge that although the battery life is good, there is little warning given before the battery dies. A bit like a pet hamster. Again, with four power settings you should optimise your battery life. Secondly, I don’t think many consumers would eagerly vote for an SMA antenna connector over a BNC, but we have to live with that. The main problem can be a snapped pin from an over-stressed SMA to SO239 adaptor, for example. This happens easily, frequently and on one occasion to me. I sent my unit back to Icom UK for repair, as the stuck pin could not be extracted. I must add that their support and service was fantastic. The repair was carried out quickly and was not costly. Chastened, I made a pigtail adaptor for use in the car, shown below.

SMA - SO239 adaptor
As far as accessories go, I have the HM-175 GPS speaker microphone. The embedded data channel in DV is something we’re only just starting to fully explore. GPS position and distance reporting between simplex users or posts on APRS.fi via a repeater are fun. I also have a two-pin mic/headset adaptor for mobile work.

Just download an electronic manual and have a look at the level of specification and configurability! You'll find a new feature every day for the first few months. There are now the lower-cost IC-E80D and 70cm-only IC-ID31E to supplement the range, of course.

So, after two years I think the big test for any bit of equipment would be “If it was damaged/stolen/confiscated by vexed YL/XYL, what would I replace it with?” For me, an exact replacement, no less. It’s a much of a staple as the King Edward potato.