Stateside on 10m again

My 10m 2W WSPR station is on now and getting plenty of stateside spots. A typical 2 mins TX burst gets 2-4 spots with most of these being from the USA and Canada. The earliest transatlantic spot (of me) was at 1118z, which is very early. These first class conditions cannot last, although I suspect next autumn will be good to the USA still.

UPDATE 1445z: I have now dropped my power to 500mW and am still getting plenty of USA WSPR spots with best DX 8756km to N6RY.  In 90 minutes there were 24 spots in the log when running 500mW out.

UPDATE 1725z: 41 spots of my 500mW 10m WSPR signal and most are transatlantic this afternoon. Plenty of reports still coming through. Suspect the band will be open transatlantic for hours yet.

UPDATE 1848z: 3 spots of my 1846z 10m 500mW transmission with best DX 6384km at a STRONG -8dB S/N.

UPDATE 1910z:  Still wide open to the USA with a report from  KI7CI at 8307km.   It could be a while yet before conditions drop out, or it might suddenly drop off.

UPDATE 1928z:  no less than 7 (yes 7) spots of my 500mW signal in a single transmission and ALL USA reports.

UPDATE 2014z: 3 spots with best DX 7660km. Band STILL wide open, even with 500mW. Even at 2020z still, getting stateside reports.

UPDATE 2040z:  10m still wide open but my last spot was at 2102z.

10m WSPR on RX - still wide open at 2042z

OFCOM and spectrum pricing (again)

Ofcom has today published a statement confirming the framework and cost allocation methodology they will apply when setting cost based spectrum licence fees. The statement also sets out Ofcom’s decision on the cost based fees to be charged to Digital Terrestrial Television (DTT) multiplex operators. The fees, which they consulted on, apply to Wireless Telegraphy Act 2006 DTT multiplex licences awarded by Ofcom.

 

To give the proposed fee changes legal effect, Ofcom needs to make amendments to the licence Fee Regulations. Ofcom expects to publish these under a Statutory Notice on which it will consult shortly. Subject to that process, new fees regulations are expected to come into force in mid-2014.

Amateur and ship charges are expected to be reviewed next year (2015) with any charges (if made) starting 2017.

Basically, I am AGAINST spectrum charging. If I was in charge I would nationalise broadband and all phones (including mobiles) and REDUCE costs for consumers. Why should share holders benefit when consumers should?

Strapped feeder results (630m), and back on 10m

Overnight I have been on 474.2kHz WSPR using the VHF/HF antennas all strapped together and tuned against mains earth. Impressions are that it performs about as well (or badly?) as the low height dedicated Marconi, perhaps a tad better? Strapping feeders is certainly easy to do.

Since about 0820z I have returned to 10m WSPR using around 2W to the Par end-fed antenna. Reports already exchanged with Japan and Reunion Is. in the Indian Ocean. Conditions still look excellent on 10m with a sunspot count of 139 currently. 10m, even with my antenna and 2W, is too easy right now!

10m - first hour with 2W to Par antenna

474.2kHz - trying strapped feeders

As a last attempt (for now) on 474.2kHz WSPR this evening I have strapped the feeders of the Par 10/20/40, the 2m halo and the V2000 tri-band VHF/UHF vertical all together and am tuning it against mains ground to see how things compare with previous tests. The "theory" is the effective vertical is about 2x higher so, if efficiency was about the same as before, the ERP would be up. In reality, the antenna current is only 10% higher so losses over the "short" Marconi must be much greater.

So far, spots of other stations appear stronger (e.g.G3XIZ -1dB S/N) but I've only managed 2 spots of my own signal, these from PA3ABK/2 in Holland at 306km. These are not brilliant, but similar to the earlier tests. More results overnight tonight.

Tomorrow I may go back to 10m.

13 unique spots of my QRPP 474.2kHz WSPR so far

So far, 13 unique WSPR spots of my signal with the very low Marconi antenna and 5-10mW ERP. Plenty of further spots likely although I want to change the antenna to ground the far end shortly. All my current experiments are with antennas I can string out without having to use a ladder (because of my mobility issues - stroke).

Best DX remains DL4RAJ (990km) although plenty of spots received from DL-SWL (701km) overnight too.

472kHz ERP over-estimates?

Looking at the reports I send and receive, I wonder if several stations are actually using a LOWER ERP than they think? From measurements I am pretty sure my ERP is 5-10mW with 5mW likely to be the closer figure. Some stations claim 0.5 to 1W ERP which is considerably more than me. Some stations ARE using 6-12dB more than me and to much better antennas but, judging by reports, I should be reporting them much stronger than I do. This could be because (1) my noise floor is worse, (2) my RX is not optimally sensitive, or (3) their ERP is lower than they think. In at least some cases (3) is the reason.

Nearest 474.2kHz report

This afternoon I received a MASSIVE +12dB S/N 474.2kHz WSPR report from G4PZW who is located about 1km  (or less) from here. He is in the same QTH square (JO02dg).  I met Rob for the first time last weekend at the Burwell Hobbies and Interests Weekend when he was signing GB1BHW, a special event call.

New seasonal DX record on 474.2kHz last night

Last night I received several spots from DL4RAJ at 990km,which is a record, so far this year, for my QRP WSPR signals on 474.2kHz. I am hopeful of better results yet.

My 10mW EIRP maybe be a bit over-estimated as I forgot to divide the measured voltage by 1.414 to convert to RMS from peak. This means my ERP was closer to 5mW, even lower than I had expected, even though I am still showing 10mW ERP on WSPRnet.. This proves, even more, that high power and fancy big antennas are NOT needed to have fun on 474.2kHz MF.

12 unique WSPR spots in last 24 hrs with QRPP on 474.2kHz

EIRP calculation on 472kHz band

So I plugged my measured figures into the equations to work out ERP on the 472kHz band with the very low height Marconi.  Measured antenna current is 0.64A and effective height about 1.6m.  The formula gives EIRP taking  into account the lack of directivity.

EIPR (472kHz) = I^^2 * Heffective^^2 /100  (source LF Today 3rd edition)
                          = 0.64*0.64*1.6*1.6 / 100 = 10.48mW

ERP is 1.8/2.52 times the above figure, so around 7.5mW.

My estimate of 10mW  ERP is a few dB too high, but not a bad estimate, considering experimental error.

As the ERP is proportional to current and effective height both squared, it is easy to see how ERP can be much improved by increased antenna vertical height, increasing the power, or doing both. The other thing is to reduce system losses.  An antenna/earth that looks like 300 ohms is probably lossy.

Sputnik days

A message from Oleg RV3GM :

Dear Sputnik'ers

Welcome to "Vanguard-1 QRPp Party 2014"
Dates - March 17 to April 7.
This is not a contest but activity days only. Enjoy milliwatting using old type
Ge transistors TX. See details here -
http://club72.su/vanguard.html

Wish you all the best, 72!
Oleg "Mr. 72" RV3GM / KH6OB
=== In QRP We Trust ===