Thursday, April 29, 2010

Easypal - Digital SSTV

A couple of evenings ago, I called CQ on 50.150 on the drive home and was called by Nick, G1URJ at Wallingford. Had a nice chat with him and he mentioned an interest of his was SSTV. I said, 'Ah, you'll know my friend Bob, G0ADH who does SSTV too...'.

Nick said that indeed he did, but that his own interest was in Digital SSTV. I had to confess that I hadn't come across Digital SSTV as opposed to Analog SSTV transmitted by MM-SSTV and the like.

Nick mentioned EasyPal written by Erik, VK4AES - and having gone through some of the websites devoted to it, the pictures are quite spectacular, with error free pictures being shown. Have a look at some examples on G0HWC's website - impresive pictures.

Easypal is free to download and use. Nick mentioned 3.733 is a good place to start listening - with 14.233 the 20m frequency. You only need a regular digimodes interface, so it should be quite easy to get going.

I've never got hugely into SSTV, but it's a fun thing to try and really great for demonstrations. Easypal is certainly on my list of things to try out.

Wednesday, April 28, 2010

GB3VHF 144MHz beacon: It's back!

I just checked GB3VHF's frequency (144.430) and am delighted to hear the beacon active again. Obviously it's hard to tell whether it's a better or worse signal than the old site, but it's certainly a great signal here at the moment, so it will be interesting to keep an eye on it over the next little while and see how the signal holds up.

Well done to Chris, G0FDZ for all his work getting the beacon reestablished. You can read about the beacon and plans for the future here.

It's great to hear GB3VHF once more.

Monday, April 26, 2010

G4VXE/M back on 50MHz SSB


Over the last couple of years, I've enjoyed having the FT8900's FM capabilities on 50MHz. I've missed having SSB on 50MHz though. This year I thought it would be fun to try and have both.

Over the weekend, I sorted out a simple installation for the IC706 in the car and connected up an old Larsen 50MHz magmount for 50MHz. It all seems to be working and I can hear the 'local' 50MHz beacons; GB3RAL and GB3BAA quite reliably. Hopefully, before long, I'll hear something a bit more distant.

Talking to Des, G0RBD this morning, he mentioned he'd got some 50MHz Es over the weekend, so with any luck it won't be too long.

Friday, April 23, 2010

My first 50MHz FM mobile QSO of the year

Driving home last night, I was calling CQ on 51.510MHz as I'd mentioned a couple of days back. I was completely floored to get a reply! Jeff, M0UHF answered my call! Jeff is located in Abingdon, so the contact was only over a few miles - but the signals were great.

We thought we'd better move off the calling frequency. I was so surprised to be called, I forgot that the 50MHz FM channels are at 20khz spacing, rather than 10khz! We moved to 51.520 but as Jeff said at the time, we really should have moved to 51.530. I don't suppose it mattered on that occasion, but I'll get it right next time!

Thanks, Jeff!

CQ0HAR 29MHz repeater now active

Southgate ARC report that a new 29MHz FM repeater is active. CQ0HAR from Portugal. The output is on 29.690MHz and the input 100khz below at 29.590MHz.(Thanks Julian for spotting my typo - this originally said 29.580!) CTCSS tone is 67hz.

If the Es propagation picks up a little bit, it shouldn't be long before we can hear this from the UK. It'll be well worth adding this frequency to the list of 29MHz FM channels to be scanned.

Wednesday, April 21, 2010

More on KP4AO's EME activity - listen for yourself!

Last week, I blogged about the KP4AO 432MHz EME activity with the Arecibo dish. The expedition group had some problems with amplifiers, but with such an impressive array, even quite low power works well.

Joe, K1JT writes,

I'm home again, but not yet unpacked and re-organized...

Many thanks to all stations we worked from KP4AO -- and our apologies to the many more who called without completing a QSO. The Arecibo telescope's short moon windows were frustrating for all, ourselves included.

The "wall" of stations calling was simply incredible. A rough estimate suggests that we may have worked something like 20% of the callers potentially workable on SSB, 10% of those workable on CW, and only a few percent of those workable on JT65. I guess we'll have todo it again, in due course...

From memory: our log shows nearly 240 completed QSOs with some 57 DXCC entities, in a total of 8 operating hours. Later, when I have the log in front of me and get caught up at home, I'll be able to report breakdowns of SSB, CW, and JT65B QSOs and say something about the QSO rates in each mode.

We made recordings of the whole 432 MHz EME sub-band for for most of the time KP4AO was on the air. In due course it will be possible to "tune the band" carefully, many times, picking out callsigns. If/when this is done, I'll be happy to post a list of received callsigns.

Here's a request for all:

1. If you worked us with a setup significantly smaller than is normally required for EME, please send me a short note describing your antenna, receiver, and Tx power.

2. If you copied us with a small setup, please send me details on your antenna and receiver.

I know we worked and were heard by some pretty small setups, and I'd like to document some of them for a write-up in QST.

Many thanks, and see you on the moon!

73, Joe, K1JT


I was really impressed with an audio recording made by Graham, G8NWC which he posted on Twitter. Graham used an FT817 with no preamp and a small 10ele yagi on a tripod in the back garden. Have a listen to Graham's recording here

Tuesday, April 20, 2010

D-STAR gossip: CODECs and France

Had a nice chat with Neill, F5VLD (G4HLX) at the weekend. Many of you will remember Neill as the hardworking adjudicator of the Practical Wireless QRP Contest for many years. Neill's working overseas, currently, based in Aix-en-Provence, though when he's at home, he's one of my locals in Oxfordshire. I caught up with Neill for a chat on D-STAR.

Neill was using a DV-Dongle and told me that largely speaking, D-STAR is illegal in France, though there are a few stations with NoVs around Paris who can use D-STAR on RF. Let's hope that situation can be resolved in due course, so that French stations may enjoy D-STAR too.

What was interesting though, was that Neill mentioned the fact that D-STAR uses a proprietary CODEC (recognised by the ITU) gives some hope that D-STAR will be recognised in France. If it was a 'freeware' CODEC developed independantly, then there would be very little chance, currently, of D-STAR being approved for use in France. Should a 'freeware' CODEC become used in D-STAR as an alternative, I wonder if it could be 'approved' by the ITU?

Getting going on six metre FM for the 'season'

As we get towards the end of April, I start to think about Sporadic E openings on 50MHz becoming more common - or at least we can hope!

So, for the last couple of days, on the drive home from the station in the evening, I've been setting one of the VFOs on the FT8900 onto 51.510MHz FM. 51.51 is the European 50MHz FM calling frequency. So far, I've not heard anyone, but I have tried a few CQ calls.

If you have 50MHz mobile or FM available, why not give it a go? And if you're within 30 to 50 miles of South/West Oxfordshire, please look for me around 1715-1745z - it would be great to hear you on six metres FM!

Wednesday, April 14, 2010

FOC's President proposes 'DX Code of Conduct'

In a commendable statement, the President of the First Class CW Operators' Club (FOC), Bob Whelan, G3PJT has proposed a 'DX Code of Conduct'.

DX CODE OF CONDUCT

1. I WILL LISTEN, AND LISTEN, AND THEN LISTEN SOME MORE

2. I WILL ONLY CALL IF I CAN COPY THE DX STATION PROPERLY

3. I WILL NOT TRUST THE CLUSTER AND WILL BE SURE OF THE DX STATION'S CALL SIGN BEFORE CALLING

4. I WILL NOT INTERFERE WITH THE DX STATION NOR ANYONE CALLING HIM AND WILL NEVER TUNE UP ON THE DX FREQUENCY OR IN THE QSX SLOT

5. I WILL WAIT FOR THE DX STATION TO END A CONTACT BEFORE CALLING HIM

6. I WILL ALWAYS SEND MY FULL CALL SIGN

7. I WILL CALL AND THEN LISTEN FOR A REASONABLE INTERVAL. I WILL NOT CALL CONTINUOUSLY.

8. I WILL NOT TRANSMIT WHEN THE DX OPERATOR CALLS ANOTHER CALL SIGN, NOT MINE

9. I WILL NOT TRANSMIT WHEN THE DX OPERATOR QUERIES A CALL SIGN NOT LIKE MINE

10. I WILL NOT TRANSMIT WHEN THE DX STATION CALLS OTHER GEOGRAPHIC AREAS THAN MINE

11. WHEN THE DX OPERATOR CALLS ME, I WILL NOT REPEAT MY CALL SIGN UNLESS I THINK HE HAS COPIED IT INCORRECTLY

12. I WILL BE THANKFUL IF AND WHEN I DO MAKE A CONTACT

13. I WILL RESPECT MY FELLOW HAMS AND CONDUCT MYSELF SO AS TO EARN THEIR RESPECT.

It would be nice to think that this would make a difference to some of the behaviour we hear all too often on the bands.

Will it? Time will tell, but each journey starts with a simple, hopeful step.

Read more about Bob, and FOC's initiative here.

A new QRP podcast: PARP QRP!

Jerry Taylor, KD0BIK produces and presents the successful and popular 'Practical Amateur Radio Podcast. In a new venture, which I'm really sure is going to be very popular, he's produced a short 5 minute podcast about QRP called PARP QRP.

Check it out! And thanks, Jerry, for kindly linking to my article about the DVAP.

GB3VHF antenna rigging complete....

You'll remember reading that the GB3VHF 144MHz beacon in SE England has been relocated from its old site at Wrotham to a new site, for cost reasons. The beacon went off air a few weeks ago.

The good news is that according to the 'GB3VHF Relocation News' web page the antenna rigging is complete, and once Chris, G0FDZ receives the keys to get into the compound, the beacon will be on air again!

Exciting news. Keeping the beacon on air costs money. If you value the beacon's services - and that really ought to be most of us who enjoy VHF DXing - take a moment to send Chris a donation through Paypal. Send it to chris at g0fdz dot com (you know how to change that address to use it!) and mark it "GB3VHF Donation".

I'll post again when I hear the beacon for the first time. I'm looking forward to seeing how the signal strength compares from the new site.

'Guest' VHF/UHF column for RADCOM written

If you're an RSGB member, you'll find a guest columnist writing the 'VHF/UHF' column again in the May issue, me!

It was fun writing it - and thanks to those of you who read this blog, or follow me on Twitter who very kindly gave me some material to use. I think I managed to include it all - though I did notice that a few paragraphs here and there had been edited out for space reasons. That's the nice thing about writing a blog rather than a magazine article - you can include what you want!

Hope you enjoy the column - it was fun to write for RADCOM again.

Wednesday, April 07, 2010

Would you like to hear Puerto Rico on 432MHz? Maybe you can hear KP4AO

Via the ever useful Southgate ARC blog , comes the following news item on some activations of the 1000ft dish antenna at Arecibo in Puerto Rico.

In an activation last month, David, G4DHF worked KP4AO using 2 x 21 element yagis on 432MHz EME and got a 59 report! Many stations have reported hearing KP4AO on a single yagi. I'm planning to try and have a listen myself and see what I can hear.

The Arecibo Observatory Amateur Radio Club will be putting the 1000-foot radio telescope on the air for 432 MHz EME from April 16-18.

It can be heard with a small hand-held yagi pointed at the moon

The scheduled times of operation are:
April 16: 1645 - 1930 UTC
April 17: 1740 - 2020 UTC
April 18: 1840 - 2125 UTC

Callsign: KP4AO

Tx Frequency: 432.045 MHz
Rx Frequency: 432.050 to 432.060+
Tx power: 400 W
Antenna gain: 60 dBi
System noise temp: 120 K (cold sky)
System noise temp: 330 K (when pointed at moon)

KP4AO can be heard with a small hand-held yagi pointed at the moon and a good receiver. A 15 dBi antenna and 100 W will be enough to work us on CW.

Operators at KP4AO will do their best to work as many stations as possible. Each session will start with a brief announcement and CQ in SSB. SSB QSOs may continue for 30 minutes to an hour, if the QSO rate remains high.
The mode will be shifted to CW as soon as it is judged that higher QSO rates would result.

We will listen for calls at frequencies 5-15 kHz higher than our own, and even higher if QRM warrants. Callers who s-p-r-e-a-d o-u-t are more likely to be copied.

If you've already worked us in any mode, please do not call again -- give others a chance.

If we call "CQ QRP", we will listen for stations running 100 W or less to a single yagi. Please do not answer such a CQ if you are running more power or have a larger antenna.

On April 18, if we reach a condition where most calling stations have been worked, and we judge that operating in the digital mode JT65B would produce a higher QSO rate, we will switch to JT65B.

Note that any of these planned operating strategies may be changed as circumstances dictate.

We are extremely fortunate to have been granted access to the world's largest radio telescope for this amateur radio good-will event. We look forward to working as many stations as possible in the alloted time!



73 from Joe, K1JT
on behalf of all the gang at KP4AO

Sunday, April 04, 2010

Setting up the DVAP or, D-STAR coverage in the henhouse


I was delighted that on Thursday, my DVAP Dongle arrived from the USA. I've mentioned the DVAP Dongle before. It runs, in conjunction with a PC or MAC and your Internet connection in providing 2m D-STAR coverage using a small 10mW transceiver built into the dongle.

The idea is that the coverage is limited to 100 feet or so around the dongle (actually it seems a little wider than that!) allowing you to use your D-STAR handheld around the house. This is ideal for me here as I have limited D-STAR coverage available via RF. The DV Dongle has proved a real boon in the shack, but it's nice to be able to have the HT with me out in the garden, when I'm cleaning out the henhouse or attending to other little jobs. Julian, G4ILO raised a very valid point on his blog about the licencing issues around unattended operation. I'm only using the DVAP when I'm in the house or round about, so shutdown is a matter of seconds - so I'm considering that my DVAP operation is 'attended'. If you want to restrict use of the access point to your own callsign, you can do that, or you can open it up to other calls, if you wish. I've actually also reduced power of the DVAP to around half power, as the coverage at that level is more than adequate.

Set up of the DVAP was really simple. You need the FTDI drivers on your PC, which I already had by virtue of the DV Dongle. I then downloaded the DVAP Tool program and installed it. That was it as far as the PC is concerned. You just open the virtual com port and set the frequency where you want to use your access point. I determined that 144.750 was quiet locally, so I've used that, but it's easy to set the DVAP to any frequency you like.

Connecting to reflectors and D-STAR nodes is all achieved from your D-STAR rig and is really straightforward. If you want to connect to REF001C it's just a question of setting REF001CL in the UR call field. Blip the transmitter up and you should quickly get a voice announcement from the DVAP saying 'Remote system linked'. Change the value of UR to CQCQCQ and you're all set to go.

You can do an echo test (locally) with the DVAP. Just put DVAP E in the UR field and transmit and the DVAP will echo your audio back to you. Or DVAP I will identify the access point - useful for checking coverage of the access point.

Lots of nice QSOs so far - my wife Julie was impressed with a chat with KF7DQF/M in Utah when I was sat on the sofa next to her.

So there it is. I'm enjoying the DVAP. I got mine from the USA. It was a bit pricey to bring in, once VAT and Parcelforce's handling charge were taken into the account, but that's what you pay for being an early adopter. It's a super bit of kit and it's really expanded my D-STAR horizons.

And Pru the chicken can listen to my D-STAR contacts when I'm cleaning out her house!

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