3 Mar 2010
Fivehead QRP SSB transceiver kit
This afternoon Ted G4NUA came around to test the receiver section of his Fivehead 20m SSB transceiver kit from Walford kits in Somerset. I was surprised how small the transceiver was. We checked the RX with a signal generator and re-did the alignment. We then tried it on an external antenna and it was about the same sensitivity as the FT817 and was copying plenty of stations on 20m SSB. Ted has still to finish the TX part. When done it should put out about 1.5W pep.
1 Mar 2010
Warm sunshine and G3XBM up a tree
Today the sun has been shining and it's quite warm so I've been up the neighbour's tree lopping branches so that they don't obstruct the light. It is a field maple and it grows so fast. I took down branches about 4 metres long and these have grown in the last 3-4years. There is also a method in my madness: there's a sturdy branch just the right height to act as a support for the end of my longwire. It's twice as high as the original on the clothes line support. So, when the job is done I'll string out some black PVC covered wire. Also, for the first time this year I managed a cup of tea on the patio: maybe spring really is almost here at long last.
28 Feb 2010
11th country on 500kHz
Just had a 500kHz WSPR report from MW0CVT 250kms to the west of me. This is now my 11th country from which I've had reports on the band. This is also my 83rd unique report on the band.
Amateur DXing below 9kHz (VLF)
Some recent discussion on the LF Reflector is suggesting that distances of >100kms should be workable with amateur stations below 9kHz, albeit running QRO exciters. This would be possible with optimised stations and antennas and very slow QRSS modes. As an example, see the email posted this evening by RA9MB:
I was wonder if it is posible to use a loop on 9 kHz. Serious problem to radiate 9 kHz is high voltage we saw. Loop has that advantage that voltage is not too high. Then i do some estimations. Let's assume vertical loop 15m x 50 m with 20 mm diameter coper tube as a wire. Then effectivity of such a loop on 9 kHz is about -65 dB. It is adequate to radiate 1 mW
on 9kHz (I=250A, TX power about 4 kW). We saw such a radiation should give abt 100 km distance in QRSS. Besides such a loop is well suited for 136 kHz. On 136 kHz it effectivity should be about -25 dB. Not too bad: 1 W radiation with 400 W TX :-)
26 Feb 2010
QRP transatlantic on 80m
Just got a report from W1XP on 80m WSPR when running just 1W into the 5m long vertical. DX is 5280kms. Report suggests that 500mW would also have crossed the pond.
New Zealand gets 500kHz (for now)
From March, New Zealand amateurs will be allowed to use 505-515kHz. The number of administrations making temporary allocations is increasing all the time now. Expect some ZL-USA (and maybe Europe?) tests before long on the band. I wonder who will be the first to receive some 500kHz WSPR beacons from the Antipodes?
Labels:
500kHz,
new zealand,
wsjt
Australia on 40m QRP tonight
It really is too easy with WSPR on HF. Last night some reports from Antarctica and tonight a brief 5W transmission on 40m got me another report from VK6POP in Australia. One of my projects is a micropower WSPR beacon for 10m, but it will have to be something like 10mW to be anything like a challenge :-)
First sub-9kHz NoV application with OFCOM
G7NKS has already submitted his application for an NoV to operate below 9kHz. Mine will be prepared in the next few days. Approval (or rejection) may take some time as OFCOM has to consult with the Met Office first. The Met Office monitors <9kHz for sferic activity to track storms and lightning.
25 Feb 2010
NoV permits for operation below 9kHz
OFCOM has informed me today that, subject to acceptable outcomes of consultation with other sub-9kHz spectrum users such as the Met Office, they will consider issuing NoVs (similar to those issued for 501-504kHz) to existing UK radio amateurs to permit operation at frequencies below 9kHz. Any such operation would be on a non-interference basis. Application forms should be submitted to Rod Wilkinson at OFCOM (with as much detail as possible) using the NoV form available at http://www.ofcom.org.uk/radiocomms/ifi/licensing/classes/amateur/applications/ofw306.pdf
Subscribe to:
Posts (Atom)