Something that's been puzzling me for the last couple of years, particularly on the digital modes, is the number of people who address me by name before I've told them. These are not stations I've worked before - KComm will alert me to those. But increasingly often when I reply to a station they will come right back with "Good afternoon, Julian." I've even had people end JT65A contacts with "TU JULIAN 73", despite the fact that the operator's name is not part of the exchange.
I'm not egotistical enough to think that half of hamdom know my name because of my blog. I've had people address me as "Mr Julian Moss" which I think is a bit formal for the amateur bands. But it makes me suspect that some database is involved.
It would shake my faith in the parsimony of hams to think that 50% - because that's about how often it happens nowadays - have stumped up for a subscription to QRZ. But if they haven't, where do they get the information from? Is there a free callsign lookup database I haven't heard of? And if there is, doesn't the fact that you can access a station's details at the click of a button render somewhat pointless the rest of the QSO?
Wednesday, February 27, 2013
Tuesday, February 26, 2013
Andalucia Day
Andalucia Day, as this link will tell you, is the anniversary of a referendum held in 1980 in which people voted for the southern province of Spain, Andalucia, to become an autonomous region. This year that anniversary falls on 26 February, today.
I love Andalucia. The name immediately conjures up for me a vista of whitewashed villages nestling among rugged mountains, memories of walks on mountain paths and lazy days enjoying a glass or three of local wine in a tapas bar.
I often used to dream of living in an Andalucian village. I could happily have become one of the many British expats out there. But dreams don't always turn out how you imagine. The endless sunshine seems irresistible but summers can be unbearably hot and as one gets older you start to need things like healthcare, which is good, free and English-speaking in Britain. In view of what has happened to me in the last two years it's probably a good thing I didn't become an expat!
Still, I can't look at a picture like this without feeling nostalgic!
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| Canillas de Albaida, Andalucia |
Monday, February 25, 2013
A 40m transceiver kit
It has been a while since my soldering iron has been warmed up and I have been feeling the urge to build something. The challenge of building something from scratch has usually proved too much, so I have decided to build a kit. I've read a lot of good things about the "Iler 40" and its 20m brother so I decided to get one.
I thought that this kit was sold on Ebay but a search for "Iler 20" came up blank. A more generic search produced some interesting hits including this 40m transceiver kit from a UK seller. This kit is quite a bit cheaper than the Iler kits but without any reviews it is a bit of an unknown quantity. I eventually found that the Iler kits can be bought from the maker's own site. The excellent reviews plus a higher output (4w vs 1w) were the decider. I was a bit unsure of which version to go for but I eventually plumped for the 40m version. More to follow once it gets here.
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| Iler 40 transceiver (EA9GCY photo) |
Sunday, February 24, 2013
QSLs sent
I have just sent a new batch of QSLs via GlobalQSL for printing and distributing via the bureau. I like the Global QSL service. It takes away the chore of sending QSL cards and reduces the work to a simple log export to ADIF file.
I had to purchase 1000 new card credits before I could upload them. Today's batch, from last summer until now, was over 400 contacts on 398 cards. That's excluding local FM QSOs and contest contacts. I didn't realize I was so active on the air. At that rate I'll be ordering another batch before the year is out!
I had to purchase 1000 new card credits before I could upload them. Today's batch, from last summer until now, was over 400 contacts on 398 cards. That's excluding local FM QSOs and contest contacts. I didn't realize I was so active on the air. At that rate I'll be ordering another batch before the year is out!
Saturday, February 23, 2013
The prettiest ham and the longest call
Fifteen metres was again in good shape today. The contacts I made included the prettiest ham I've yet worked, and the station with the longest call I've ever logged.
Call me a male chauvinist if you like, but whenever I work a YL (young lady) on the bands I can't resist looking to see if I can find a picture of her. I worked Natali from Moscow on PSK31 this afternoon and she must be the prettiest ham radio operator I've worked in my long career. She keeps a pretty neat shack, too.
The prize for the longest callsign ever logged goes to YO2013EYOWF which is the official call of the European Youth Olympic Winter Festival 2013 in Brasov, Romania. I pity anyone having to send that in CW! I don't have any pictures of the YO2013EYOWF operators but they do have a very pretty logo which I expect will be on their QSL.
.jpg) |
| Natali, RV3ADL |
eQSL fraud?
In the last couple of weeks I have received two eQSLs for contacts that never happened. The QSLs were from made-up callsigns that are clearly SWLs, e.g. UA-123456. But the message with the card says simply: TNX For QSO TU 73! Curiously, both QSLs contained exactly the same wording.
Now I have nothing against SWLs. I started in this hobby as a broadcast SWL and I feel that all hams should have had experience as an SWL to get familiar with procedures, propagation and so on. But I am uncomfortable with receiving eQSLs from listeners as the eQSL system has no way to distinguish a listener report from an actual contact so their presence messes up my totals.
In practice it isn't a big mess-up as I have never received an SWL card from a country I haven't had a proper QSO with. So I do accept eQSLs that make it clear they are for reception of a contact I made. But TNX FOR QSO? Who do they think they are kidding, and what do they hope to gain from it?
Now I have nothing against SWLs. I started in this hobby as a broadcast SWL and I feel that all hams should have had experience as an SWL to get familiar with procedures, propagation and so on. But I am uncomfortable with receiving eQSLs from listeners as the eQSL system has no way to distinguish a listener report from an actual contact so their presence messes up my totals.
In practice it isn't a big mess-up as I have never received an SWL card from a country I haven't had a proper QSO with. So I do accept eQSLs that make it clear they are for reception of a contact I made. But TNX FOR QSO? Who do they think they are kidding, and what do they hope to gain from it?
Friday, February 22, 2013
Wide boys
What's the point of PSK125? I just finished a session running PSK31 on 15m (which was really lively, by the way) when I thought I'd just check 10m to see if anything was going on up there. I soon found that there wasn't much. The waterfall was devoid of traces, apart from a weak, wide, nebulous trace which proved to be PSK125. PY2DN was calling CQ, but try as I might he couldn't decode me.
It appeared that he was making some QSOs, presumably with people enjoying better 10m propagation than I had. PY2DN's signal was far from perfect copy. Most times he transmitted I received mostly garbage. But I'm sure there was enough energy in the transmission to produce solid copy had he been using PSK31.
I guess the point of PSK125 is speed. PY2DN's CQ and my reply both lasted about two seconds. But what's the hurry? Not only can I not type that fast, I can't even click macro buttons that fast. So the time saved is for nothing. I accept there is a role for PSK63 in contests, when speed matters, but only when signals are strong enough to provide good copy. PSK125 is a step too far. It spreads the energy too thinly.
I've tried loads of new digital modes but I keep on coming back to good old PSK31. I find it more satisfying in the long run. There's tons of activity from heaps of different locations. You can often find a PSK31 signal when the CW and SSB band segments are dead. PSK31 is a real QSO mode where you can actually converse with somebody and exchange information with them. And you don't need to run a kilowatt to a huge tribander to be successful. I was calling CQ on 15m with 40w to my attic dipole and I felt like a big gun: I was getting replies, including DX replies, to every other call.
I think PSK31 has earned its place alongside CW and SSB as one of the staple modes of amateur radio. Other modes are just for temporary amusement.
It appeared that he was making some QSOs, presumably with people enjoying better 10m propagation than I had. PY2DN's signal was far from perfect copy. Most times he transmitted I received mostly garbage. But I'm sure there was enough energy in the transmission to produce solid copy had he been using PSK31.
I guess the point of PSK125 is speed. PY2DN's CQ and my reply both lasted about two seconds. But what's the hurry? Not only can I not type that fast, I can't even click macro buttons that fast. So the time saved is for nothing. I accept there is a role for PSK63 in contests, when speed matters, but only when signals are strong enough to provide good copy. PSK125 is a step too far. It spreads the energy too thinly.
I've tried loads of new digital modes but I keep on coming back to good old PSK31. I find it more satisfying in the long run. There's tons of activity from heaps of different locations. You can often find a PSK31 signal when the CW and SSB band segments are dead. PSK31 is a real QSO mode where you can actually converse with somebody and exchange information with them. And you don't need to run a kilowatt to a huge tribander to be successful. I was calling CQ on 15m with 40w to my attic dipole and I felt like a big gun: I was getting replies, including DX replies, to every other call.
I think PSK31 has earned its place alongside CW and SSB as one of the staple modes of amateur radio. Other modes are just for temporary amusement.
Sunday, February 17, 2013
ARRL DX contest
There is still a few hours of the ARRL DX CW contest to go but I have worked all that I want to work this weekend. I only took part for fun, so no targets to beat. I did hope to work some of the rarer west coast states but conditions didn't allow it. I only worked W/VE stations - in fact I only worked US stations, the VEs were conspicuous by their absence. I did hear one VE but I never managed to work him. So in comparison to other contests my haul of contacts was worse than normal.
I operated for a couple of hours late Saturday morning, and the same again after lunch. On Sunday morning I did another couple of hours but I almost gave up as I seemed to be hearing all the same stations I worked on Saturday. Then the jinx left and I managed to log another batch of new stations. But by Sunday afternoon I'd had enough, and it was a fine late winter day so I went for a walk by the river with Olga.
I think conditions this weekend were below average. Ten metres was all but dead; 15m was quite productive but the money band as usual was 20m. I didn't try the lower bands as I think my attic antennas are too much of a compromise on those bands to work DX with them.
My total of 55 stations worked is nothing to write home about, but remember I was only working US stations - I ignored all the Europeans and Russians whom I would have worked in a normal contest. I worked 20 different states: CT, FL, GA, IL, MA, MD, MN, NC, NH, NJ, NY, OH, PA, RI, SC, TN, TX, VA, VT and WI. So my 100W was barely making it past the east coast. If anyone is interested in my full log the contest starts on this page.
Working in a contest is always fun. It's not the winning, it's the taking part that counts!
I operated for a couple of hours late Saturday morning, and the same again after lunch. On Sunday morning I did another couple of hours but I almost gave up as I seemed to be hearing all the same stations I worked on Saturday. Then the jinx left and I managed to log another batch of new stations. But by Sunday afternoon I'd had enough, and it was a fine late winter day so I went for a walk by the river with Olga.
I think conditions this weekend were below average. Ten metres was all but dead; 15m was quite productive but the money band as usual was 20m. I didn't try the lower bands as I think my attic antennas are too much of a compromise on those bands to work DX with them.
My total of 55 stations worked is nothing to write home about, but remember I was only working US stations - I ignored all the Europeans and Russians whom I would have worked in a normal contest. I worked 20 different states: CT, FL, GA, IL, MA, MD, MN, NC, NH, NJ, NY, OH, PA, RI, SC, TN, TX, VA, VT and WI. So my 100W was barely making it past the east coast. If anyone is interested in my full log the contest starts on this page.
Working in a contest is always fun. It's not the winning, it's the taking part that counts!
Thursday, February 14, 2013
A JT65-HF update
Due to the health issues of the developer Joe Large W6CQZ it has been some time since there was a new version of the popular JT65-HF application. So I was interested to receive an email from Erwin, DK5EW, telling me about an enhanced version of JT65-HF made by Matthias DL3VCO called JT65-HF-Comfort.
Matthias has not made an add-on to JT65-HF in the style of programs like JT-Alert. Instead he has made changes to the actual JT65-HF source code. I was particularly pleased to see that the enhanced version retains compatibility with the popular add-on JT-Alert by Laurie, VK5AMA. When I tried recompiling the JT65-HF source code myself the new version did not work with Laurie's program, which I regard as an essential aid to JT65A operating. (In fact I have cheekily asked VK5AMA if he would consider making a version of JT-Alert that works with K1JT's WSJT-X program!)
I have not spent much time with JT65-HF-Comfort as my interest at the moment is directed towards the new JT9 mode, but you can see from the screenshot that one of the improvements DL3VCO has made is to display the callsign above each trace on the waterfall. He has also added a new Statistics menu which displays the number of contacts you have made per DXCC entity per band. I couldn't show you that as I use KComm for logging so my log is not in a format that JT65-HF-Comfort can read. You can find a Google-translated version of the JT65-HF-Comfort information here.
If you are interested in trying JT65-HF-Comfort then you can download a setup program (a modified version of W6CQZ's installer) to install the updated version. I shall certainly try using it the next time I do some JT65A operation.
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| JT65-HF as enhanced by Matthias, DL3VCO |
I have not spent much time with JT65-HF-Comfort as my interest at the moment is directed towards the new JT9 mode, but you can see from the screenshot that one of the improvements DL3VCO has made is to display the callsign above each trace on the waterfall. He has also added a new Statistics menu which displays the number of contacts you have made per DXCC entity per band. I couldn't show you that as I use KComm for logging so my log is not in a format that JT65-HF-Comfort can read. You can find a Google-translated version of the JT65-HF-Comfort information here.
If you are interested in trying JT65-HF-Comfort then you can download a setup program (a modified version of W6CQZ's installer) to install the updated version. I shall certainly try using it the next time I do some JT65A operation.
Wednesday, February 13, 2013
My first JT9-1 QSO
PC4T Paul's blog post about working Tasmania with 5 watts gave me the spur to try the new JT9-1 mode, so I installed the WSJT-X software. The user interface is quite a bit different to the older WSJT programs but most of the same controls are there. I never really figured out how to use WSJT, much preferring the simpler interface of Joe W6CQZ's JT65-HF application.
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| Working SM5CS using JT9-1 mode |
My experience with JT65-HF stood me in good stead as I was familiar with the sequence of exchanges, but I missed the JT65-HF user interface, its ability to decode all the signals in a swath of spectrum, and the alerts and built-in logging of it's companion JT-Alert application.
My first QSO, also using 5 watts, was with SM5CS - not as impressive as Tasmania but sufficient to satisfy myself that I knew how to drive the program. I'm puzzled by the panoramic display though: the two peaks of the spectrum analyzer display don't match up with the two traces shown on the waterfall.
I made the changes to KComm to allow me to log this new mode. I seem to have an increasing number of modes that I can log but not upload to eQSL.cc because the ADIF specification doesn't yet include them, though JT9 is already there.
Tuesday, February 12, 2013
ARRL DX Contest questions
I see that the ARRL DX CW contest is next weekend. I haven't decided yet whether I will come on and give away a few points, nor whether I will operate QRP or run 100 watts. I think it will depend on propagation.
One thing I am unsure about is what exchange to send. I believe DX stations - which means me in this context - are supposed to send RST and power.
If I'm running QRP (5 watts) do I send "5NN 5" or "5NN 005" or even "5NN TT5"?
If I'm running 100 watts would I send "5NN 100" or "5NN 1TT" or even "5NN ATT"? These short form numbers confuse me a bit. I've heard 1 being sent as A, and 0 (zero) being sent as the letter "O". Or at least, I think I have.
If I change the power as I normally do and run 100W only when it is needed do I send the actual power I am using or stick to the same exchange (100W) throughout the contest?
Do I work only US stations or will all stations, even Europeans, benefit from working me with a point?
One thing I am unsure about is what exchange to send. I believe DX stations - which means me in this context - are supposed to send RST and power.
If I'm running QRP (5 watts) do I send "5NN 5" or "5NN 005" or even "5NN TT5"?
If I'm running 100 watts would I send "5NN 100" or "5NN 1TT" or even "5NN ATT"? These short form numbers confuse me a bit. I've heard 1 being sent as A, and 0 (zero) being sent as the letter "O". Or at least, I think I have.
If I change the power as I normally do and run 100W only when it is needed do I send the actual power I am using or stick to the same exchange (100W) throughout the contest?
Do I work only US stations or will all stations, even Europeans, benefit from working me with a point?
Monday, February 11, 2013
A blinking nuisance
It's beginning to look as if my shack PC monitor is on the blink. Recently I have noticed that when the system comes back to life after going into standby the picture flashes repeatedly - flash, blank screen, flash, blank screen and so on. Nothing I do seems to bring this cycle to a halt, I just have to wait until the picture eventually stabilizes on its own.
This morning for the first time this occurred upon powering up the system from cold. So it looks as if the problem is getting worse. One day soon I expect the picture may not stabilize at all.
It is a 19 inch (48cm) monitor and must be about 8 years old, bought at a time when 19 inch monitors were quite a pricey item. So I can't complain that I haven't had good use out of it. I must have had three different system units in all that time. I should take this as an opportunity to replace it with a newer, larger screen. Except for the fact that I don't really have the room for a larger monitor as my shack is so small.
I do have a laptop that I could use. It is a nice wide-screen Dell running Windows 7, purchased for work about 3 years ago but now little used as I have given up most of the things I used to do. The trouble with that idea is that the laptop doesn't have the 4 real serial ports and 6 USB ports that the shack PC has, all of which are used.
So I guess I'll be shopping for a new PC monitor some time soon. The thing that always puts me off buying new computer hardware is the fear that it will be RF-noisy and add to the already high noise levels I experience here. This old monitor actually causes some hash on the 2m band, which went unnoticed when it was new as I didn't use VHF at the time. I think I'll ignore cheap Chinese products for once and stick with one of the well-known European brands that have actually passed emissions tests instead of just sporting a CE sticker like I suspect many imports do.
This morning for the first time this occurred upon powering up the system from cold. So it looks as if the problem is getting worse. One day soon I expect the picture may not stabilize at all.
It is a 19 inch (48cm) monitor and must be about 8 years old, bought at a time when 19 inch monitors were quite a pricey item. So I can't complain that I haven't had good use out of it. I must have had three different system units in all that time. I should take this as an opportunity to replace it with a newer, larger screen. Except for the fact that I don't really have the room for a larger monitor as my shack is so small.
I do have a laptop that I could use. It is a nice wide-screen Dell running Windows 7, purchased for work about 3 years ago but now little used as I have given up most of the things I used to do. The trouble with that idea is that the laptop doesn't have the 4 real serial ports and 6 USB ports that the shack PC has, all of which are used.
So I guess I'll be shopping for a new PC monitor some time soon. The thing that always puts me off buying new computer hardware is the fear that it will be RF-noisy and add to the already high noise levels I experience here. This old monitor actually causes some hash on the 2m band, which went unnoticed when it was new as I didn't use VHF at the time. I think I'll ignore cheap Chinese products for once and stick with one of the well-known European brands that have actually passed emissions tests instead of just sporting a CE sticker like I suspect many imports do.
Sunday, February 10, 2013
A brief spell of activity in the PACC contest
Sunday morning I was a bit late getting up. I felt like a change from listening to silence while waiting for someone to come up in DV mode so I decided to try some QRP CW using the KX3 to remove the temptation to turn the power up.
It was clear there was a contest on - the PACC contest - and I worked out that the PA stations were sending a city or county code and the rest were sending a serial number, so I decided to give away a few points.
I set the KX3 to 5 watts to keep in the spirit of QRP and started making some contacts. I thought 40m would be the best band to work Dutch stations from here. In 20 minutes I made 4 QSOs. All came back to my first call, and I was reminded that it really isn't that difficult to make contacts on the 40m band with an attic antenna and low power.
I reached the bottom of the band and started tuning up the other way but the band seemed to have gone quiet. After a few minutes a light bulb flickered on dimly in my head and I looked at the clock: 1205. I dashed downstairs to get the February RadCom and looked in the contest news. Sure enough, the PACC contest ran from 1200 Saturday to 1200 Sunday. It had finished five minutes ago!
I really should get up earlier on Sundays!
It was clear there was a contest on - the PACC contest - and I worked out that the PA stations were sending a city or county code and the rest were sending a serial number, so I decided to give away a few points.
I set the KX3 to 5 watts to keep in the spirit of QRP and started making some contacts. I thought 40m would be the best band to work Dutch stations from here. In 20 minutes I made 4 QSOs. All came back to my first call, and I was reminded that it really isn't that difficult to make contacts on the 40m band with an attic antenna and low power.
I reached the bottom of the band and started tuning up the other way but the band seemed to have gone quiet. After a few minutes a light bulb flickered on dimly in my head and I looked at the clock: 1205. I dashed downstairs to get the February RadCom and looked in the contest news. Sure enough, the PACC contest ran from 1200 Saturday to 1200 Sunday. It had finished five minutes ago!
2013/02/10
|
11:39
|
7.021
|
CW
|
PA5TT
|
599
|
001
|
599
|
ZL
| ||
2013/02/10
|
11:42
|
7.019
|
CW
|
PA6NB
|
599
|
002
|
599
|
NB
| ||
2013/02/10
|
11:45
|
7.018
|
CW
|
PA3BWK
|
599
|
003
|
599
|
UT
| ||
2013/02/10
|
11:55
|
7.011
|
CW
|
PA0AA
|
599
|
004
|
599
|
UT
|
I really should get up earlier on Sundays!
Tuesday, February 05, 2013
Buying batteries on Ebay
Yesterday I wanted to experiment with using a ferrite rod antenna for WSPR. I was using my AA-200 antenna analyzer to try to tune the antenna when it suddenly restarted. I switched it off and on again and as soon as I chose any function the analyzer restarted again.
The last time I used the AA-200 I remember the batteries ran out so I charged it. It appears that after 6 years of use the rechargeable battery pack won't hold a charge.
I'm useless at taking things apart but Olga managed to open the battery pack to reveal a shrink wrapped pack of 4 AA cells. I could have ordered a replacement from Strikalite but their price was £20. I found an Ebay seller in Hong Kong whose price was a quarter of that. So for the sake of a few days wait I could save myself £15.
I ordered the battery pack, but this morning there were two emails in my inbox saying "We are sorry to tell you that we are not allowed to dispatch batteries recently for the customs are very strict on exporting batteries." Is this something new? It's the first I have heard of it. I've certainly bought battery packs (including batteries for handheld transceivers)from China on Ebay before.
The seller has refunded my money (or at least he has said he will.) In the meantime I found a UK seller of Chinese batteries, Vapextech UK, which, while not as cheap as the Hong Kong seller, is still a third of the price of Strikalite. Having said that, Strikalite is still a good firm to go to if you want to refurbish a ham radio battery pack and like me you are useless at taking battery packs apart.
The last time I used the AA-200 I remember the batteries ran out so I charged it. It appears that after 6 years of use the rechargeable battery pack won't hold a charge.
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| AA-200 antenna analyzer and open battery pack |
I ordered the battery pack, but this morning there were two emails in my inbox saying "We are sorry to tell you that we are not allowed to dispatch batteries recently for the customs are very strict on exporting batteries." Is this something new? It's the first I have heard of it. I've certainly bought battery packs (including batteries for handheld transceivers)from China on Ebay before.
The seller has refunded my money (or at least he has said he will.) In the meantime I found a UK seller of Chinese batteries, Vapextech UK, which, while not as cheap as the Hong Kong seller, is still a third of the price of Strikalite. Having said that, Strikalite is still a good firm to go to if you want to refurbish a ham radio battery pack and like me you are useless at taking battery packs apart.
Monday, February 04, 2013
My second DV QSO
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| Elie, OD5KU |
I replied to Elie but he couldn't make out my call. I tried several times and was about to give up when he called again with solid copy. Perhaps he had turned his beam my way. I tried calling one more time. This time he heard my reply and we had a good QSO with several periods of solid copy punctuated by occasional break-ups. These occurred when QSB took the digital signal down to near-invisibility in the FreeDV waterfall. I doubt that good SSB copy would have been possible at those times either.
I managed to make a recording of the end of this QSO so you can get an idea of the audio quality. It was recorded off-air using my Olympus digital voice recorder, then played back using the mic input of the USB sound dongle to make an MP3 file. Given the way it was created I think the clip is quite a good example of the FreeDV audio quality. As you'd expect from a digital signal either it's all there or you just get gobbledygook. It doesn't degrade gracefully.
Is this the future of ham radio? Have a listen and let me know what you think.
My first DV QSO
I was in the shack, messing about with ferrite rods trying to replicate Roger G3XBM's success using a ferrite rod as a transmit antenna. Meanwhile I was monitoring 14.236MHz, the 20m digital voice calling frequency.
Some audio came through the PC speakers. I didn't catch what it was, but the callsign OZ1BXN appeared below the DV application waterfall. I waited, and shortly Chris called again. We completed a QSO with 100% solid copy each side. I gave Chris 5 by 8, which was the actual K3 S meter reading, and Chris gave me 5 and 9. Chris said he was running 200W peak power. I had the K3 in DATA mode with the power level set to 25W which is the recommended level to use with a 100W transceiver. Whether that results in an average or a peak power of 25W I have no idea.
Although Chris's signal was solid copy with no dropouts the audio was rather boxy and I found it more difficult to read than a typical SSB signal. This is probably a consequence of the fact that Codec2 has been designed to use a 1.4kHz bandwidth rather than the 2.8kHz required by SSB. I can understand the thinking behind this decision but I agree with David G8JGO who commented on one of my earlier DV posts that it is a pity the codec wasn't designed to give better than SSB fidelity within an SSB bandwidth. I think that would make the adoption of digital voice more compelling. I can see many people, particularly skeptics who can't see the point of digital voice at all, being turned away by the audio quality. Has DV shot itself in the foot?
Having said that, Chris reported that I had very good audio. I had tweaked the equalisation built into FreeDV to give some treble emphasis and bass cut, so perhaps some adjustments are possible.
Some audio came through the PC speakers. I didn't catch what it was, but the callsign OZ1BXN appeared below the DV application waterfall. I waited, and shortly Chris called again. We completed a QSO with 100% solid copy each side. I gave Chris 5 by 8, which was the actual K3 S meter reading, and Chris gave me 5 and 9. Chris said he was running 200W peak power. I had the K3 in DATA mode with the power level set to 25W which is the recommended level to use with a 100W transceiver. Whether that results in an average or a peak power of 25W I have no idea.
Although Chris's signal was solid copy with no dropouts the audio was rather boxy and I found it more difficult to read than a typical SSB signal. This is probably a consequence of the fact that Codec2 has been designed to use a 1.4kHz bandwidth rather than the 2.8kHz required by SSB. I can understand the thinking behind this decision but I agree with David G8JGO who commented on one of my earlier DV posts that it is a pity the codec wasn't designed to give better than SSB fidelity within an SSB bandwidth. I think that would make the adoption of digital voice more compelling. I can see many people, particularly skeptics who can't see the point of digital voice at all, being turned away by the audio quality. Has DV shot itself in the foot?
Having said that, Chris reported that I had very good audio. I had tweaked the equalisation built into FreeDV to give some treble emphasis and bass cut, so perhaps some adjustments are possible.
Sunday, February 03, 2013
No QSOs
I spent all of Saturday monitoring the FreeDV suggested frequencies but so far I haven't heard a thing. I am really surprised. Whenever a new data mode is announced the main problem is usually QRM as too many people pile eagerly on to the recommended frequencies. FreeDV is a development that is potentially as revolutionary for the hobby as the advent of SSB in the 1960s. I would have thought that more hams would want to be in at the start, especially as there is no cost apart from the time taken downloading the software.
Perhaps people just don't know where to go. Since my last post I have discovered the FreeDV QSO Finder. This is a tool to enable potential users of FreeDV to find out where others are. Suggested frequencies are: 14.236, 7.190 and 5.4035, though I've seen people using other frequencies. This weekend's contest will probably put the kibosh on attempts to set up contacts for now, but I hope for better luck next week when the bands are quieter.
Perhaps people just don't know where to go. Since my last post I have discovered the FreeDV QSO Finder. This is a tool to enable potential users of FreeDV to find out where others are. Suggested frequencies are: 14.236, 7.190 and 5.4035, though I've seen people using other frequencies. This weekend's contest will probably put the kibosh on attempts to set up contacts for now, but I hope for better luck next week when the bands are quieter.
Friday, February 01, 2013
Digital voice on HF
I was going to title this post "D-Star's nemesis" but I thought that would be too provocative and premature! But the much talked-about Codec2 open source voice codec has just surfaced in usable form, in the shape of an easy to use bit of software called FreeDV.
FreeDV is available for Linux, Windows and Mac. I installed the Windows version, which is just a matter of extracting the files from a zip archive into a folder.
If you're set up to run digital modes on HF then you're half way there already. FreeDV uses the same sound card as your digimode software and the same audio levels. As with PSK31 you just need to make sure you aren't driving the transmitter into ALC.
You'll need a second sound card for the receive and transmit audio. Assuming that you aren't using one sound card for both digimodes and computer sound, this will be the one you use for Windows noises. On my shack PC that's one of those el cheapo eBay USB sound card dongles. You'll also need a microphone or a computer headset.
There's no VOX (perhaps that will come in a later version of FreeDV) so you have to click a button to toggle PTT. Before you can do that you need to set up PTT using a com port. In my case the same serial port used for CAT control and updating the firmware of my K3 was used. The rig went straight into transmit until I ticked the RTS +V check box.
The main challenge is finding other people who are using FreeDV. At the moment the frequency 14.236MHz on 20m seems to be the only calling frequency. It would be nice to have some centres of activity on other bands, but no doubt that will come in due course. There's a Digital Voice Google Group which will probably become the meeting place for FreeDV users.
A FreeDV transmission is 1.1kHz wide, less than half of the bandwidth of an SSB signal. The audio is best described as telephone quality. It's a bit boxy, but there is an equalizer called "Filter" in the software that can be used to brighten up both the transmit and receive audio. A nice feature of the software is a button that lets you instantly switch between analogue and digital so you can easily make comparisons. I wish I could include a clip of the audio recorded off air but I couldn't figure out how to do it.
Right now I'm sitting on 14.236MHz waiting for someone else to come on the frequency. Hopefully as the word gets out more people will get on the air with FreeDV and contacts will be easier to come by.
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| FreeDV running on Windows |
If you're set up to run digital modes on HF then you're half way there already. FreeDV uses the same sound card as your digimode software and the same audio levels. As with PSK31 you just need to make sure you aren't driving the transmitter into ALC.
You'll need a second sound card for the receive and transmit audio. Assuming that you aren't using one sound card for both digimodes and computer sound, this will be the one you use for Windows noises. On my shack PC that's one of those el cheapo eBay USB sound card dongles. You'll also need a microphone or a computer headset.
There's no VOX (perhaps that will come in a later version of FreeDV) so you have to click a button to toggle PTT. Before you can do that you need to set up PTT using a com port. In my case the same serial port used for CAT control and updating the firmware of my K3 was used. The rig went straight into transmit until I ticked the RTS +V check box.
The main challenge is finding other people who are using FreeDV. At the moment the frequency 14.236MHz on 20m seems to be the only calling frequency. It would be nice to have some centres of activity on other bands, but no doubt that will come in due course. There's a Digital Voice Google Group which will probably become the meeting place for FreeDV users.
A FreeDV transmission is 1.1kHz wide, less than half of the bandwidth of an SSB signal. The audio is best described as telephone quality. It's a bit boxy, but there is an equalizer called "Filter" in the software that can be used to brighten up both the transmit and receive audio. A nice feature of the software is a button that lets you instantly switch between analogue and digital so you can easily make comparisons. I wish I could include a clip of the audio recorded off air but I couldn't figure out how to do it.
Right now I'm sitting on 14.236MHz waiting for someone else to come on the frequency. Hopefully as the word gets out more people will get on the air with FreeDV and contacts will be easier to come by.
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