Following feedback, Rik Strobbe ON7YD updated his list of countries with (or about to get) access to the new MF band as follows:
Monaco (18/05/2012)
Malta (11/06/2012)
Germany (13/06/2012)
Philippines (30/08/2012)
Slovakia (01/09/2012 ?) - special licence(s)
Czech Republic (01/09/2012 ?) - special licence(s)
Sweden (01/10/2012) - special licence(s)
Norway (30/10/2012)
Greece (01/11/2012)
New Zealand (20/12/2012)
Australia (01/01/2013)
Denmark (01/01/2013)
The Netherlands (01/01/2013)
UK (01/01/2013) - available to full licence holders by NoV
Switzerland (01/01/2013)
Finland (early 2013)
Spain (early 2013)
Showing posts with label 472-479khz. Show all posts
Showing posts with label 472-479khz. Show all posts
12 Dec 2012
11 Dec 2012
Countries with access to 472-479kHz
An interesting post on the LF reflector today from Rik Strobbe ON7YD - OR7T about which countries have, or soon will have, access to the new MF band.
This was Rik's list:
Monaco (18/05/2012)
Malta (11/06/2012)
Germany (13/06/2012)
Philippines (30/08/2012)
Slovakia (1/09/2012)
Czechia (1/09/2012)
Sweden (1/10/2012)
Norway (30/10/2012)
Greece (1/11/2012)
Denmark (1/01/2013)
Netherlands (1/01/2013)
United Kingdom (1/01/2013)
Switserland (1/01/2013)
This was Rik's list:
Monaco (18/05/2012)
Malta (11/06/2012)
Germany (13/06/2012)
Philippines (30/08/2012)
Slovakia (1/09/2012)
Czechia (1/09/2012)
Sweden (1/10/2012)
Norway (30/10/2012)
Greece (1/11/2012)
Denmark (1/01/2013)
Netherlands (1/01/2013)
United Kingdom (1/01/2013)
Switserland (1/01/2013)
Labels:
472-479khz
10 Dec 2012
UK NoV changes
OFCOM has announced some intended changes to the Notice of Variations issued to some radio amateurs in the UK. See http://licensing.ofcom.org.uk/radiocommunication-licences/amateur-radio/full-licence-jan-2013/ . The main changes are to the 5MHz band (more fixed frequencies), the removal of 501-504kHz NoVs and the release, by new NoV application, to the new 472-479kHz band. Changes are expected to come into force from Jan 1st 2013. Details of how to obtain the new NoVs has not yet (to my knowledge) been made known.
Labels:
472-479khz,
500kHz,
5mhz,
ofcom
12 Nov 2012
Another 472/500kHz transverter built stateside
Just got this nice email from John WA3ETD/WG2XKA who has successfully built another copy of my 472/500kHz transverter.
"Hi Roger,
I completed your design XVTR Saturday here, on the air on WSPR last evening had eight uniques and flawless operation.
I slightly modified the PA by adding the gate resistor and diode, as well as driving the FET via a cap. I only had surface mount IRF-510, that is the raised, floating copper heatsink that sits on two tiny standoffs at drain potential.
Thanks again for publishing your design! PIX attached.
73,
John WA3ETD / WG2XKA"
"Hi Roger,
I completed your design XVTR Saturday here, on the air on WSPR last evening had eight uniques and flawless operation.
I slightly modified the PA by adding the gate resistor and diode, as well as driving the FET via a cap. I only had surface mount IRF-510, that is the raised, floating copper heatsink that sits on two tiny standoffs at drain potential.
Thanks again for publishing your design! PIX attached.
73,
John WA3ETD / WG2XKA"
WG2XKA's version on my 472/500kHz transverter |
Labels:
472-479khz,
500kHz,
transverter,
wg2xka,
wspr
10 Nov 2012
Delay getting 472-479kHz released in the UK?
On the GQRP Yahoo group today Colin, G8FRA/M5FRA, posted this message regarding the release of the new 472-479kHz band in the UK. If his information is correct, there could be some delay in the bulk of UK amateurs gaining access to the new MF band. This would be a great pity.
"Roger,If this information is correct, then why is our national society, the RSGB, not making this public? I have written to OFCOM and the RSGB asking for more concrete information.
From what I learned by talking to a couple of people at Newark (RSGB and OFCOM) we will not get the new allocation in Jan 2013. Those with existing SRPs will have them changed to remove 500kHz and add 472-479kHz. I asked when applications would reopen and there was no date for that. Evidently OFCOM have to consult before there can be any changes to the license schedule and have been too busy with the Olympics to make any progress on that. I did suggest that the RSGB should come clean as anybody who has spent time and money on new equipment might just be a bit disappointed.
Colin - G8FRA/M5FRA
m5fra.org.uk"
Labels:
472-479khz,
gqrp,
mf,
rsgb
6 Nov 2012
Norway gets 472-479kHz right away
Norway has been granted immediate access to the new MF band with CW and all digital modes permitted. See https://www.nrrl.no/318-news/ latest-news/492-lb1g . I hope some LA stations come on to WSPR in the new band this evening.
Labels:
472-479khz,
norway
More 474.2kHz WSPR
This evening I am copying 3 stations, so far, on 474.2kHz USB dial WSPR: SM6BHZ and DK7FC are both good signals with QSB but I've also copied DL3ZID at -27dB S/N. QSB is slow and it takes about 12 minutes for DK7FC's signal to go from -27dB S/N to -12dB S/N.
Labels:
472-479khz,
wspr
472kHz transverter (rev K)
SM6BHZ and DK7FC this afternoon on 472kHz WSPR |
Labels:
472-479khz,
dk7fc,
sm6bhz,
transverter
14 Oct 2012
MF WSPR activity at an all-time high
MF WSPR activity this evening |
Labels:
472-479khz,
500kHz,
mf,
wspr
18 Sept 2012
472kHz transverter - real progress
Since reverting to a passive double balanced mixer based design, the circuit is now behaving properly with no signs of oscillation and a good clean signal from the PA. Although I have used an SBL1 mixer, it will work with any similar mixer package. Tomorrow I may try the design with an NE602 as this would allow the separate oscillator to be removed. With an NE602 it should be possible to do the complete TX-RX transverter with 1 IC, 2 transistors and 1 FET. Now THAT would be neat.
Labels:
472-479khz,
ne602,
transverter
16 Sept 2012
472kHz transverter "progress"?
This afternoon, after a break of a few weeks, I went back to my 10W 472kHz transverter design. The intention was to simply build a second sample to prove repeatability. As is often the case, things didn't quite work out that way: instead I discovered an MF oscillation when drive was removed in some situations. Despite trying all the usual tricks so far, I've not managed to fix it yet. It is not the PA: driving it and the squarer stage directly with a 472kHz signal all is well. It looks like a problem around the oscillator and mixer but so far I have not managed to tame it. Also, and this is probably the same issue, on RX there is a wideband noise resulting in desensitisation. For this evening I have stopped work and will take a fresh look tomorrow. Maybe the double balanced mixer in my original 2010 circuit was not such a bad idea after all.
This is a classic situation when a spectrum analyser would really help as I could see in an instant where the trouble was by poking around with an RF probe and observing the spectrum on the analyser.
This is a classic situation when a spectrum analyser would really help as I could see in an instant where the trouble was by poking around with an RF probe and observing the spectrum on the analyser.
Labels:
472-479khz,
500kHz,
transverter
5 Sept 2012
On with the projects.....
Back home now, so it is on with the autumn projects list.
Several people have been contacting me about the latest 472/500kHz 10W transverter. Someone in OK-land is designing a PCB and I hear a "dead bug" version has been successfully built in the USA - not sure whether an exact copy or "based on" - but it has already been used on MF WSPR with a report from over 2000km up the USA east coast. So, I will continue with refining this design first and then get on with the "WIPSY" 28MHz simple WSPR transceiver next.
The non line-of-sight optical beaconing tests will resume a little later when the evenings start to draw in. I want to set up a more powerful, semi-fixed 481THz optical beacon so that I can do a series of DX tests under various degrees of cloud cover. Tests last winter suggest much further will be possible than the 9km NLOS ranges achieved with clear air scatter when signals were audible by ear. By using much lower sub-carrier frequencies the optical detector sensitivity will be very much greater allowing even weaker signals to be detected on QRSS3 and QRSS30.
Several people have been contacting me about the latest 472/500kHz 10W transverter. Someone in OK-land is designing a PCB and I hear a "dead bug" version has been successfully built in the USA - not sure whether an exact copy or "based on" - but it has already been used on MF WSPR with a report from over 2000km up the USA east coast. So, I will continue with refining this design first and then get on with the "WIPSY" 28MHz simple WSPR transceiver next.
The non line-of-sight optical beaconing tests will resume a little later when the evenings start to draw in. I want to set up a more powerful, semi-fixed 481THz optical beacon so that I can do a series of DX tests under various degrees of cloud cover. Tests last winter suggest much further will be possible than the 9km NLOS ranges achieved with clear air scatter when signals were audible by ear. By using much lower sub-carrier frequencies the optical detector sensitivity will be very much greater allowing even weaker signals to be detected on QRSS3 and QRSS30.
Labels:
472-479khz,
481thz,
projects,
transverter,
wispy,
wspr
22 Aug 2012
The second 472kHz transverter (with MeSquares)
Partially built 472kHz transverter using MeSquare islands |
Labels:
472-479khz,
mesquares,
transverter
19 Aug 2012
LF/MF Loop antennas on transmit
For the last few winters I've used a wire loop antenna on 136 and 500kHz transmit with moderately successful results. Well, considering the extremely low ERP it is better to say excellent results. My wire is not that thick: around 1mm PVC covered multistrand wire and the loop area around 80m square, with the lower part of the wire either very close to, or actually on, the ground. Using the TX loop calculator at http://www.66pacific.com/calculators/small_tx_loop_calc.aspx the efficiency is around -30dB at 500kHz, so that 5W from the PA would result in around 5mW ERP radiated. My calculations and measurements, with less than ideal loop geometry, suggest the ERP is some 3dB lower at around 2-3mW. At 137kHz the loop is considerably less efficient at around -50dB.
For a small plot with nearby trees I am not sure how well this compares with a small Marconi with a short vertical section (around 6m max) and a horizontal section of around 6m. Anyone know the answer?
For a small plot with nearby trees I am not sure how well this compares with a small Marconi with a short vertical section (around 6m max) and a horizontal section of around 6m. Anyone know the answer?
Labels:
137khz,
472-479khz,
500kHz,
antenna,
lf,
loop,
mf,
transmit loop
Another country on 472-479kHz
Lubos OK2BVG reports that he has been granted access to the new 630m MF band and is already working stations. Gradually more countries are gaining access although I doubt UK amateurs will be allowed access to the band before January 2013.
A few years ago I was extremely excited when Lubos managed to copy my 2mW ERP 500kHz WSPR beacon at over 1000km for the first time. Since then the beacon has reached Finland at almost 1800km.
It is good to hear that several German stations are now active in the new band with conventional CW QSOs being quite common.
A few years ago I was extremely excited when Lubos managed to copy my 2mW ERP 500kHz WSPR beacon at over 1000km for the first time. Since then the beacon has reached Finland at almost 1800km.
It is good to hear that several German stations are now active in the new band with conventional CW QSOs being quite common.
Labels:
472-479khz,
630m,
OK2BVG
26 Jul 2012
472/500kHz antenna improvements needed
For the last month whilst testing my 472/500kHz transverter I've been using a highly compromised antenna. Essentially it is a very short Marconi tuned against my central heating system ground. The first 6-7m is a coax cable running next to pipes in the loft horizontally. Eventually the coax runs outside and up 5-6m to my 6m/10m halos. The coax inner and outer are strapped together when used on 500kHz. In the last week we have had a new central heating boiler fitted, this time in the loft, so there are even more copper pipes and wires running close to the coax. Reports appear to be a few dB worse on 500kHz as a result.
The time has now come to design a "no compromise" 500kHz Marconi! Looking at the geometry of my garden I should be able to erect a 5-6m vertical away from the house with some 10m of horizontal top loading. I can add some inductance near the top of the vertical section and tune it all against a reasonably decent ground (4 x 1m long earth spikes, a couple of radials and the central heating copper). Not sure how soon I can work on this but I would hope the ERP increase could be up to 6dB. At least with WSPR (and OPERA) one can do a series of tests over several days with each antenna and compare results. It will be easy to measure antenna current which gives a good indication of ERP when the antenna effective height is calculable.
The time has now come to design a "no compromise" 500kHz Marconi! Looking at the geometry of my garden I should be able to erect a 5-6m vertical away from the house with some 10m of horizontal top loading. I can add some inductance near the top of the vertical section and tune it all against a reasonably decent ground (4 x 1m long earth spikes, a couple of radials and the central heating copper). Not sure how soon I can work on this but I would hope the ERP increase could be up to 6dB. At least with WSPR (and OPERA) one can do a series of tests over several days with each antenna and compare results. It will be easy to measure antenna current which gives a good indication of ERP when the antenna effective height is calculable.
Labels:
472-479khz,
500kHz,
antenna,
marconi
25 Jul 2012
New MF transverter ready for testing
472/500kHz transverter built more presentably |
UPDATE 26.7.12
Tested the transverter above on-air this evening and getting reports from several stations on WSPR.
WSPR reports so far this evening on 500kHz |
Labels:
472-479khz,
500kHz,
transverter
21 Jul 2012
Results with the new 500kHz transverter
WSPR reports received this evening (40mW ERP) |
Labels:
472-479khz,
500kHz,
opera,
opera op4,
transverter,
wspr
20 Jul 2012
472/500kHz TX transverter - first schematic
10W 472/500kHz TX Transverter (CW, WSPR, OPERA, QRSS) |
Next stage is to add the RX preamp and filter and sort out RX-TX switching. I also want to try to go for a higher PA output power which will require changes to the output network.
Labels:
472-479khz,
472khz,
500kHz,
g3xbm,
qrp,
transverter
20 Jun 2012
Back home again and the 472kHz transverter
Icefield Parkway, Alberta |
One of the 8 black bears we encountered - this one VERY closely |
I am trying to decide on the choice of IF as I want to use an unmodified FT817. 28MHz will allow 472-479kHz to appear "in-band", but at 28MHz the start-up drift as the LO settles will still be some tens of Hertz. This hasn't proved problematic with WSPR, so guess this is my choice. At least the dial will directly read the "right" frequency e.g. 28.477kHz will correspond to 477kHz.
In view of the picture above, I am not sure what power the transverter will use bear-foot (sorry, weak joke).
Labels:
472-479khz,
630m,
transverter
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