I've just noticed a couple of SPAM comments (these were adverts for dodgy anti-virus help) which have been removed. I am sorry these got there at all. My anti-SPAM catches most dodgy stuff.
Please SPAMMERS take note: comments on my blog are regularly checked and ANY SPAM will be removed as soon as possible. Don't even think about leaving blatant adverts or similar on this blog as they will be removed! You have been warned.
On the subject of warnings NEVER click on links you are unsure of or can't trust. This is a sure-fire way to get your PC compromised or hacked.
15 Aug 2014
Blog numbers
It is hard to see why visits to this and my other Miscellaneous Musings general blog vary so much.
Today, for example, this blog had nearly 900 visits by breakfast time here, whereas yesterday it was less than half this number. It is not as if the content has changed that much. I try to put new content on both blogs regularly. If you have any ideas, please let me know.
Today, for example, this blog had nearly 900 visits by breakfast time here, whereas yesterday it was less than half this number. It is not as if the content has changed that much. I try to put new content on both blogs regularly. If you have any ideas, please let me know.
Now on 10m for the day
At 1018z I switched to 10m for the day. Even just before this GM4SLV(896km) was still spotting my QRPp signal several times in daylight on 472kHz. Nonetheless, evenings and overnight are more productive on 472kHz.
Sunspot count today is up at 108 and stable with 20-30MHz propagation "normal". We should see F2 DX today on 10m.
UPDATE 1047z: So far no WSPR spots here on 10m. It is early still though.
UPDATE 1055z: Spoke a moment too soon: EA5CYA (1376km) has just been spotted at 1048z on 10m Es.
UPDATE 1120z: CT1JTQ (1843km) spotted me at 1118z on 10m Es.
UPDATE 1405z: This lunchtime I've received 10m Es WSPR spots (I run 2W ERP) from, Spain. Portugal and Germany. There is still plenty of Es about on 10m.
Sunspot count today is up at 108 and stable with 20-30MHz propagation "normal". We should see F2 DX today on 10m.
UPDATE 1047z: So far no WSPR spots here on 10m. It is early still though.
UPDATE 1055z: Spoke a moment too soon: EA5CYA (1376km) has just been spotted at 1048z on 10m Es.
UPDATE 1120z: CT1JTQ (1843km) spotted me at 1118z on 10m Es.
UPDATE 1405z: This lunchtime I've received 10m Es WSPR spots (I run 2W ERP) from, Spain. Portugal and Germany. There is still plenty of Es about on 10m.
472kHz - more reporters
Last evening and overnight, I let 472kHz WSPR run and was rewarded by being spotted by 2 new reporters for this summer. G7NKS (who has spotted me in earlier seasons) reported me last evening and G7MRV (192km) spotted me during the night. For G7MRV it was his first venture onto the band. He was copying Germans at 1141km, an impressive range. This now brings the number of unique spotters of my QRPp signal this summer up to 12. I really do believe my ERP is just under 5mW. There are plenty more stations in range that should be able to spot me.
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| 472kHz - unique WSPR spots to date |
14 Aug 2014
At last! A new spotter on 472kHz WSPR
At 1954z I returned to 472kHz WSPR and was immediately copied by G7NKS (46km) as my 11th unique reporter this summer. OK, not too far away, but a new station for this summer.
Storms permitting, I hope to be on 472kHz WSPR all night.
UPDATE NEXT DAY: I was on 472kHz WSPR overnight.
Storms permitting, I hope to be on 472kHz WSPR all night.
UPDATE NEXT DAY: I was on 472kHz WSPR overnight.
Widegates, Kingsbridge Estuary, South Devon, UK
I'm sorry for putting this on my amateur radio blog but this is a matter dear to my heart. I come from this area and love it dearly. Because of my poor health, I have been unable to get to Devon at all this year.
There is a proposal to allow water skiing in part of the Widegates area of the Kingsbridge Estuary. This is an area of special scientific interest and at low tide a place where waders congregate. It is an area that is peaceful and quiet and of international importance.
If you know the area and want to comment, write to the Salcombe Harbour Master adam.parnell@southhams.gov.uk.
Personally, I am against the proposal. I fear the area will be adversely changed for ever.
Water-skiers are pulled by fast boats which create lots of wake and lots of noise. I may be wrong, but I fear the area will never be quite the same again if the plans are approved. The "for it" campaign people have got lots of publicity on the TV and in the press. There is a need to counter this. For democracy to work, the voices of both sides need to be heard.
There is a proposal to allow water skiing in part of the Widegates area of the Kingsbridge Estuary. This is an area of special scientific interest and at low tide a place where waders congregate. It is an area that is peaceful and quiet and of international importance.
If you know the area and want to comment, write to the Salcombe Harbour Master adam.parnell@southhams.gov.uk.
Personally, I am against the proposal. I fear the area will be adversely changed for ever.
Water-skiers are pulled by fast boats which create lots of wake and lots of noise. I may be wrong, but I fear the area will never be quite the same again if the plans are approved. The "for it" campaign people have got lots of publicity on the TV and in the press. There is a need to counter this. For democracy to work, the voices of both sides need to be heard.
ERP calculation on 472kHz
In an attempt to establish my ERP on 472kHz, I have crunched some numbers. I think it is error free, but no doubt someone will soon tell me!
With a 1:46 step up toroid, I am measuring the DC volts rectified across a 470 ohm secondary load resistor using a small 50uA meter in series with 240k ohms (120k twice) and a series silicon diode. This circuit is straight out of the "LF Today" book available from the RSGB bookshop.
DC current = 30uA
DC voltage across 470ohm secondary load = 0.6 + (240 x 10E3 x 30 x 10E-6) = 7.8V
DC voltage (rms) across 470 ohm = 7.8/1.414 = 5.52Vrms
I secondary = 5.52 * 10E3/470 = 11.7mA
I primary = 46 * Is = 46 * 11.7mA = 0.54A
Rrad = 160 * pi^2 * Heff^^2/lambda^^2 = 160 * 3.14 * 3.14 * 2 *2/(630 * 630) =0.0159 ohms
P(erp) = I^2 * R = 0.54* 0.54 * 0.0159 W = 4.6mW
My original guesstimate of 5mW ERP is not far out!
Clearly getting the antenna much higher would help enormously as ERP is proportional to Heff^^2. All one can really be sure of is the order of magnitude. I am running low milliwatts.
With a 1:46 step up toroid, I am measuring the DC volts rectified across a 470 ohm secondary load resistor using a small 50uA meter in series with 240k ohms (120k twice) and a series silicon diode. This circuit is straight out of the "LF Today" book available from the RSGB bookshop.
DC current = 30uA
DC voltage across 470ohm secondary load = 0.6 + (240 x 10E3 x 30 x 10E-6) = 7.8V
DC voltage (rms) across 470 ohm = 7.8/1.414 = 5.52Vrms
I secondary = 5.52 * 10E3/470 = 11.7mA
I primary = 46 * Is = 46 * 11.7mA = 0.54A
Rrad = 160 * pi^2 * Heff^^2/lambda^^2 = 160 * 3.14 * 3.14 * 2 *2/(630 * 630) =0.0159 ohms
P(erp) = I^2 * R = 0.54* 0.54 * 0.0159 W = 4.6mW
My original guesstimate of 5mW ERP is not far out!
Clearly getting the antenna much higher would help enormously as ERP is proportional to Heff^^2. All one can really be sure of is the order of magnitude. I am running low milliwatts.
Sunspots
Sunspot count today is 68 and 20-30MHz propagation "normal", so 10m F2 propagation is possible N-S although I've seen no evidence here on WSPR yet. There seems little doubt now that we are on the slide down to the next minimum now. See http://www.solen.info/solar/ . This will takes years. The slide downwards tends to be slower than the climb up.
I do hope people stick with the higher HF bands during the whole cycle: we'll learn a lot if people do.
I do hope people stick with the higher HF bands during the whole cycle: we'll learn a lot if people do.
More 472kHz disappointment overnight
Yet again, a disappointing evening and night on 472kHz. The same stations are spotting me and I am spotting them. Reports are quite decent and I would have expected to have spotted, and been spotted by, far more stations by now. Just like 6m , the problem is too few active WSPR stations on the band. Such a shame as 472kHz is a fascinating band and WSPR a superb mode for weak signals.
As long as the storms abate, I shall be back on 472kHz again this evening, ever hopeful. I'd like to be spotted by at least 3 times the number of stations.
As long as the storms abate, I shall be back on 472kHz again this evening, ever hopeful. I'd like to be spotted by at least 3 times the number of stations.
10m Es - good (until storms stopped play)
There was plentiful 10m Es about this morning, until I had to disconnect everything at 1205z because of very close storms. Spotting me were OZ7IT and CT1JTQ and I was spotting EA6GF and EA5CYA. Es has been present since (at least) 0850z when I first turned 10m WSPR on.
At the moment (1215z) the storms are only a few miles away - hence going QRT (for now).
UPDATE 1450z: Storms have move on now. EA6GF (1428km) is being spotted many times here at decent strengths this afternoon on 10m WSPR.
UPDATE 1511z: EA5CYA (1376km) now being spotted on 10m WSPR. Thunder is still being heard, but distantly. I shall have to keep checking how close any nasty storms come.
UPDATE 1540z: Thunder and lightning again very local, so all systems disconnected again for safety.
At the moment (1215z) the storms are only a few miles away - hence going QRT (for now).
UPDATE 1450z: Storms have move on now. EA6GF (1428km) is being spotted many times here at decent strengths this afternoon on 10m WSPR.
UPDATE 1511z: EA5CYA (1376km) now being spotted on 10m WSPR. Thunder is still being heard, but distantly. I shall have to keep checking how close any nasty storms come.
UPDATE 1540z: Thunder and lightning again very local, so all systems disconnected again for safety.
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