Friday, 26 July 2013
Monday, 7 January 2013
From the PW webpage:
Practical Wireless magazine is available from UK High Street newsagents such as WHSmith or postal copies can be purchased direct from the publisher using a Debit or Credit card by ringing 0845 803 1979 (Monday to Thursday, 8.30am to 4.00pm) – the cost is the same because there is no postage to pay for delivery to addresses in the UK.
1) I haven't got time to get to WHS in the next week
2) Ringing? rnging? Why can't I buy a PDF copy online and read it NOW!
The antennas are a couple of long wires, running similar but not identical routes, and an inductively loaded vertical I bought many years ago from sandpiper aerials - it's been lying behind the garage where it was placed when we moved house a few years ago, and everything is seized. I set it up on a fence at the bottom of the garden. It has now grown its own earth stake. I can't tune it for resonance because of the corrosion so the setup I made when it was new is stuck in place. Two or three of the bands - 12,15 and 17 metres - tune reasonably well directly. 40m is a complete no-go, and the others needed tuning.
A few months ago the winner, on most bands, was a LW/earth stake, tuned through an SGC Mac-200 to my Icom 756 ProIII.
Now, things are very different. I have spent the day with this trio, moving down the bands. So far, I've played with 21MHz,14 MHz, 17MHz and 10MHz. The 817 / LW appears to be deaf. It's generally around 12dB down on the winner. The Winner is the corroded Sandpiper which is, as I write, capturing some Stateside stuff on 30m which neither of the others sniff at. The 756 is pretty effective on the LW, generally turning in about 3-6dB down on the vertical
So what has changed? I'm guessing saturated ground probably has a fair bit to do with it. The earth on the vertical must be pretty effective at the moment, since the ground is sodden.
I'm trying to work out why I now find the 817 deaf. I'm sure I remember being pleasantly surprised by it....
I hope to move down to 3.5 and 1.8 this evening. I am confidently predicting that the vertical, with an immense loading coil on it, will not out-perform a long wire. And, of course, on 160m there is no choice.
The situation on 80m is surprisingly even. All three systems perform around the same level - in each case, one is a few dB up or down on the others, and all three have good and bad moments. I'm surprised the Sandpiper does so well. Or, maybe, to put it another way, are the long wires doing badly?
the next step is to rotate the antennas around the rigs
Sunday, 6 January 2013
And decent antenna systems. I'm now using a 3 element delta, horizontally polarised about 18 feet up, with a reasonably good take-off to the south-east. That's about as good as it's going to get round here.
I distinctly remember, in SOTA days, a session from the High Willhays, Dartmoor. In those days, we drove down overnight. I'd left the family sleeping in the car to go for a walk with the dog:
At least one of these (I can't remember who) nearly lost his eggs and B in his rush to get to the mic. I was on a handheld. Ah, the power of lifts.
So, I'm expecting rather better than this, sometime.
Saturday, 5 January 2013
Anyway, to cut a long and common story short, Santa bought me a 6m portable mast for Christmas. The aged Sandpiper 3 element delta beam sits beautifully on it, and I made up a westflex cable some time ago for 23cms (currently no antenna...)
So, it all fits together. What to listen for? There was the excitement of the Quadrantids. I capured these on a collinear:
160200 13.6 4230 12 37 -197 EA3AXV CQ EA3AXV CQ EA3AXV CQ EA3AXV C
And, a little later,
232400 14.4 400 10 26 -20 S!CQ 352 OK2PMS CQ 352 OK2PMS CQ 352 OK2
Both of which are quite gratifying on simple kit. No chance of replying, of course.
Anyway, back to the beamlet. It's been pointing towards London today. Been trawling down in the 144.135 ish region with PSK31 - no takers there, nor, indeed, anything on JT65B which is, if you read the internet, flavour of the month digitally for 2m - though I suspect all the activitiy occurs either as EME or during openings
But I did manage to pick up GB3VHF. This is located SE of London and, rather sweetly, beacons in JT65B if you set your QRG to 144.42850 USB. Today, in Shropshire, this has been a lovely -6dB, easily audible and well above the noise floor
I did try F5ZAM after that. It's a 10W beacon, probably CW, on 144.425. Pas un saucisson on that one...
Wednesday, 2 January 2013
No preamp (the Icom Pre-Amp doesn't turn on in this frequency range) but connected it up to the usual LW. The tuner doesn't seem to do very much either, but there was a ripple of activity on the spectrum display
Started up WSPR, and left it for half an hour, and here's the result.
Much better than I expected. The received wisdom was that an external preamp is needed. Well, it would undoubtedly make a difference, but I'm hearing these two guys at about -13dB, so it's "comfortable" (for WSPR).
And a nice way to open playtime with 630metres.
Monday, 24 December 2012
Unfortunately, again, all of the tasty dx hears me but I can't hear them. I think the best reciprocal contact (i.e. close to proper QSO) here is Israel.
This is 30m, 5 watts, long wire. More than I normally use with the 817. But there isn't THAT much difference with the an 817 on 2.5W with no preamp, is there? That's 817,2.5W, poor LW, this one is a considerably more expensive Icom 756ProIII, sloghtly better LW and 5W
And a Happy Christmas to All