Wednesday, November 26, 2008
Saturday, November 22, 2008
The EI3EBB 'antenna farm'. Diamond X510 on the left and a Watson 2000 on the right.
The Watson 2000 is a 3 band fibreglass VHF antenna. On 50 MHz, it is a half wave (claimed 0dBd gain), on 144 MHz it is a 2 x 5/8 wave (4dBd claimed) and 432 MHz, it is 4 x 5/8 wave (6.4 dBd). The overall lenght is 2.5 metres so the claim that it has the same gain as a half wave (3 metres) on 50 MHz is a bit optimistic.
Adjusting the 50 MHz radial on the Watson 2000
50 MHz......It has 3 ground planes with one of them adjustable for tuning the antenna to 50 MHz. The initial test showed that the VSWR was lowest up around 51 MHz. After adjusting the radial for maximum lenght, the lowest VSWR was at 50.7 MHz. The VSWR plot was as follows...
The 1:1.5 VSWR bandwidth seems to be around 0.9 MHz and the 1:2 VSWR bandwidth was 1.5 MHz. The final result is that the VSWR for the SSB portion of the band is 1:1.4 to 1.6 which should be ok. It's not that we had much choice when it came to tuning anyway because if we had adjusted it any further, the radial would have fallen out!
144 MHz....The VSWR meter suggested the following...
This suggests that the aerial was slightly too long. Certainly, the VSWR looks a bit high for the FM part of the band where this type would normally be used. As there was no way of adjusting the VSWR on 2 metres, we had to leave it as is. Did adjusting the 6 metre radial affect the VSWR on 2 metres?? We didn't check.
432 MHz....We had no equipment to check the VSWR on this band.
(Note...The VSWR was checked with a pretty cheap meter. A days later, we took some readings with another meter. While there was some differences, the VSWR minimum point stayed the same. There was nothing to suggest that the graph above is not accurate)
50 MHz.....It's way too early to say how this aerial performs on 6 metres. The only way we had of testing it was to listen to the EI0SIX beacon and compare it to how I hear it at my place. On paper, we both expected the beacon to be a lot stronger at EI3EBB's location. He is roughly double the height above sea level that I am and he is near the top of the range of hills that I have as my horizon. In addition, he is using an aerial that is resonant and should have nearly the gain of a dipole while I am just listening on a non-resonant CB half wave. If I was hearing the beacon at 319 to 419, I would have expected it to be maybe 539 at EI3EBB's place?
Instead, the beacon is very weak at his house. Why??
Is it the Watson 2000? It's hard to believe it's that bad. Anyway, it seemed to have got a good review here.
Different path???.....I looked at some maps and we have almost the same path (EI3EBB - 168kms - 38 deg / EI7GL - 183 kms - 34 deg). If anything, the path for Alan looks slightly better in that the Knockmealdown mountains look like more of an obstruction for me.
Local obstructions???......EI3EBB has some high ground to the East but at 38 degrees, he should be clear of most of it. Is there some sort of 'plateau' effect?? Is the aerial just in a null spot?
Updated 25th Nov 2008......We did a few tests by going mobile around the roads near EI3EBB's location. We used a loaded quarter wave magmount on the roof of the car and an IC706 parked on 50.052 MHz CW. Now, the tests were a bit subjective as we had ignition noise, noise from the car's electronics and there was some fading on the signal as well. Yet, we still got a good feel for what could be heard.
Area 1) Around EI3EBB's location which is about 500 metres back from the brow of the hill and at ground level, would be around 5 metres lower. The signal was very weak, maybe 319, 419 max.
Area 2) Near the peaks of the local hills (~2-3kms away, 40m higher and 15m higher) to the East and West of EI3EBB. Here the beacon was around 539, nice solid signal and a lot stronger than with the Watson 2000 at EI3EBB's place. (On the hill to the East, the signal did not really get strong until we cleared the trees)
Area 3) The strongest signals by far were along the Northern slopes of the Eastern hill. The signal peaked around 559 here, amazingly strong for a beacon that was around 165 kms away. I have seen this with VHF signals before where the signals on the downward slope of a hill in the direction of which the signals are coming are often stronger than at the top.
Conclusions....??? Still nothing definite. We established that the Knockmealdown mountains (direction of EI0SIX) are visible from the Watson 2000 on the roof. If there is any 'local' high ground in the way, it's not much. We tried just holding the magmount out a skylight on the roof so that it was close to the height of the Watson and doing some tests by comparing it to the Watson with a coax switch. We could hear the beacon a little bit better with the Watson. So, in other words, we were hearing the beacon 'a bit' better on what is supposed to be a resonant half wave antenna than a loaded quarter wave with no ground plane. Perhaps it's a bit early to come to any firm conclusion on the Watson 2000 but for the moment, on 6 metres at least, there is certainly no 'wow' factor.
144 MHz......Compared to the Diamond X510 which is nearby, the Watson is a bit down as expected. The only tests done were listening to local repeaters and they seemed fine.
(Notes....Limerick Repeater on IC706. X510=s'9+10', Watson=s'9').
432 MHz.....No tests done.
So, EI3EBB in IO52ta is back on 6 metres...
Wednesday, November 19, 2008
Tuesday, November 18, 2008
Monday, November 17, 2008
Friday, November 14, 2008
1) The HF Happenings column which covered nearly 4 pages. It's written by EI9FBB who appearently is in Cork and it's obvious it takes a fair bit of work to put it together. I'm not sure if after reading it, I'd go try chasing DX again ;o) but a good article all the same.
2) DXCC awards gained by EI stations, especially the single band ones. This was the aspect that I used to be interested in.....getting DXCC on a band rather than just using a combination of bands. Each band has it's own characteristics and the challenge for me was to see if it was possible to get DXCC on each band using just 100 watts.
The chart in the magazine is shown below...
Monday, November 10, 2008
I know it's rare....and I'm sure a lot of people were delighted to get a contact with this station....but it's only a few rocks in the middle of the ocean!! Maybe I'm after getting sceptical after my absence from the DX scene for a few years ;o) ......but to call it a seperate DXCC country seems to be really stretching credibility a bit.
Thursday, November 6, 2008
Solar Flux figures (Red line) for May 2008 to Nov 2008. More or less at or just below 70.
Solar Flux figures....
As of the start of November, we are just coming out of the sunspot minimum and conditions are very poor. Probably not the best time to get going on 10 metres again ;o)
The solar flux at the start of the month is around 69 which is very low. Direct F2 propogation would seem to be unlikely at the moment.
Tues 4th November 2008.....
Nothing at all heard on 10 metres. Listening to 11 metres, I heard some weak signals from North Italy and Spain. This was probably weak Sporadic-E, unusual for this time of year.
Wed 5th November 2008.....
Around mid-day, there was a weak Sporadic-E opening on 10 metres. I heard...
OK0EG on 28.282.46 MHz (1,690 kms). Signal about 419 (OK0EG beacon ten watts)(OK Beacon Website = 28,2825. OK0EG, nr Hradec Kralove, LOC JO70vf, ASL 240m, Ant Dipole omni, ERP 10w)
DL0IGI on 28.205.13 MHz (1,460 kms). Signal about 419. (DL0IGI JN57mt BEACON PWR 48W). The website suggests that it was 150 watts but the DX cluster confirms that I heard it ok.
I1M on 28.180.50 MHz (1,490 kms). This one was very weak, about 319. Nearest town = Bordighera. Locator = JN33UT. 5 watts to a 5/8 GP???
On 11 metres, weak German and later Spanish CB stations were heard. All signals heard were typical of single hop Sporadic-E.
Thursday 6th November 2008........
Very quiet today. Nothing at all on 10 metres. Heard a very weak Spanish station on 11 metres. Most likely weak Sporadic-E.
Friday 7th November 2008........
Another very quiet day. Nothing at all heard on 10 metres. On 27 MHz around noon, there were a few weak stations. One from Germany, one from France and one Spanish. There was very little activity and very little was heard at any one time. It was almost as if there was weak Sporadic-E conditions and only occasionally, it would get strong enough to allow propogation. Almost as if the footprint was very small and it would change very fast.
Saturday 8th November 2008.......
There seemed to be a good bit more activity today. Even the DX cluster had loads of spots. When I first checked, 10 metres was dead yet there were signals on 11 metres. As usual, it is very difficult to identify where these CB stations were coming from but they sounded Italian and Spanish. A CB station from Poland was also heard. Most of the signals were pretty weak, s '1' to '2'. The strongest station heard was s '5' but that was exceptional.Eventually, 10 metres opened up but the signal were a lot weaker than those on the CB band. I heard a ZS6 in Johannesburg but at best, he was 3/1. On the CW portion of the band, there was a OK/OM contest on as I heard CT1JLZ (max 419) and 7X0RY (max 419). An OK station was heard as well calling one of these stations.All of these signals were probably Sporadic-E although the ZS station was probably a combination of Sporadic-E for the first hop to the South and then F2 after that. Listening for the last few days, the band seems to open around mid-day. With the Summer Sporadic-E, it often seemed to open in the early morning or evening as well.
Sunday 9th November 2008.......
It was very poor today. Even though I could not listen at midday, both 10 and 11 metres sounded completely dead. Even the DX cluster had very few spots, especially from the UK or Northern Europe.
Monday 10th November 2008......
Nothing on 10 metres today, even the cluster seemed quiet. Down on 27 MHz, there seemed to be the typical weak signals around midday.....Italy, France? and Spain. The guy in Italy was running 400 watts!! Crazy power for what is supposed to be 'Citizen Band' radio :o( Anyway, even with his 400 watts, he was pretty weak so the band was just barely open. No big signals...just a few 3/1 to 4/1 signals.
Tuesday 11th Novenber 2008......
Today turned out to be pretty reasonable on the radio. Around 10:30am, I had a look around the CB band and there was a strong signal from someone near Paris in France, Sporadic-E without a doubt. Checked the Dxcluster...not much on 10 metres. Tuned around 28.2 MHz and starting hearing beacons...open at last!
Beacons....I heard the OE3XAC beacon (JN78sb - 1750 kms) on 28.188.15 MHz, DL0IGI beacon (JN57mt - 1460 kms) on 28.205.19 MHz and the DM0ING beacon (JN49ax - 1170 kms). All of these beacons are more or less due East (95 deg) from here. Then the band began to open up to the South-East. Next signal heard was the F5ZWE beacon (JN02tw - 1240 kms) on 28.242.9 MHz. It is a very distinctive beacon with it's slow cw and pips between messages. This turned out to be the most consistent beacon of the day making an appearance on and off for around 2 hours. Next signal heard was the DK0TEN beacon (JN47nt - 1330 kms) on 28.258.03 MHz. This was just after 11am and that was the last German signal that I heard for the day. Just as I was tuning up out of the beacon band, I came accross 2 QRSS or very slow speed beacons. The first one was I1YRB (JN33sf - 1530 kms) on 28.322.19 MHz, weak but audible when it gave it's ID at normal speeds. Almost on the same frequency (28.321.95 MHz), there was another QRSS beacon but because it was so weak and because the other beacon was so close in frequency, it was impossible to identify it. As far as I can tell....all I got were "iv....jn55v....qrss....3".
SSB......so on up to the SSB part of the band. F4FAZ was there with a big 5/9 signal from a location to the East of Marseilles. That was it...one big signal! Either no one was on or the footprint of the Sporadic-E propogation was small?
Beacons....Back down to check the beacons. Heard the EA4Q beacon (IN80wc - 1400 kms) on 28.263.0 Mhz near Madrid. Heard the F5ZUU beacon (JN24il - 1270 kms) on 28.241.62 MHz with only 5 watts from the South East of France.
DX....time to look around the cw portion of the band. Came accross a signal on 28.024 MHz....weak cw but the transmissions were very short...like a DX or contest station would be. Call sounded unusual so I knew it must be different....listened 2 to 3 times before I got the call 100%....7Q7BP in Malawi, Southern Africa!!...somewhere in the region of 8500 kms!! Even though he is not too strong, I give him a call with 100 watts...get him first call...exchange reports...7Q7 in the log!! My 1st contact on 10 metres in about 5 years ;o)
Tune around again...hear F5JLH on cw. Keep tuning...another weak cw signal...sounds unusual again and it's long! Listen a few times again to make sure....3B8DB in Mauritius in the Indian Ocean!! Give him a call...get back 'EI7??'...try again...gets it, exchange reports and 3B8DB is in the log! So maybe this CB half wave isn't so bad after all? Certainly, in the direction of 7Q7 and 3B8, the antenna is not clearing the house and is obstructed somewhat by the house itself. Without a doubt, working them on cw made the contacts possible. If it had been on SSB, I might have worked the 7Q7 but I doubt if I would have worked 3B8, the signals were just too weak for that. The unusual thing is that later when I checked my logbook, I had worked 3B8DB before on SSB on 10 metres...back in July 1988...20 years ago!! I see that back then I was using a home brew J-stick half wave so my aerials haven't improved much in that time ;o)
50 MHz....time to have a look around on 6 metres even though the CB half wave is poor on that band. Tune around...EI0SIX is there as usual....keep tuning..another signal! It's the EA3SIX beacon in JN01vo (1370 kms). Although that was the only Sporadic-E signal I heard on the band, conditions must be reasonably good if the MUF has gone as high as 50 MHz.
Back to 10m...and this period from 12:00 to 13:00 was the busiest part of the opening with the following heard.....IZ1GLX (cw), EA1ABT (ssb), F4DPT (ssb), CT1BH (ssb) and EA4GL (ssb). Eventually the signals began to fade out. Around 13:20, I found an unusual beacon.... C30P on 28.256.0 from the Principality of Andorra in the Pyrenees (JN02sm - 1280kms). I found this beacon by accident because it is very easy to miss it. It transmits for a short period giving it's ID and message and then it stops for about 1 minute....no dots, no signal, nothing! Unless you happen to be listening at the right time, you would never know it was there.
Signals slowly get weaker until the only signal left on the band is the EA3TEN beacon in JN01vo (1370kms) at around 13:40. Eventually even that fades until there is nothing left on the band. Tune down 1 MHz and there is a French station on the CB band at 5/7! Also heard over the next hour were some Spanish and Portugese stations until even these fade away.
Conclusions on todays opening...
1) The Sporadic-E started in the East and slowly moved to the South East and then South. I've seen this happen before on 6 metres during the Summer months.
2) Like the other days in November, the Sporadic-E signals seemed to peak around noon. During the Summer months, there are often 2 peaks...one in the morning and one during the evening.
3) The 7Q7 and 3B8 contacts were no doubt due to a Sporadic-E hop from Ireland to somewhere near Spain and from there via F2 to the DX stations. It really does emphasise the importance of Sporadic-E for DX contacts on 10 metres during sunspot minima. Sporadic-E allows stations at my latitude (~52 deg N) to get access to F2 propogation which is possible from Southern Europe.
4) My cw is rusty!! Ooooo... ;o)
Wednesday 12th November 2008.....
Today was in many ways almost the same as yesterday except that there were fewer signals. The CB band began to open up around 11:00 with a station in Belgium heard. Checked out the beacon band on 28 Mhz and the following beacons were heard....DL0IGI (JN57mt ), DM0ING (JN49ax) and DK0TEN (JN47nt)...all pretty weak signals. Eventually, these beacons and the activity faded away around. The band seemed closed arond 12:00 except for a single French CB station down on 27 MHz, all alone with a 5/7 signal!! It was almost as if the footprint of the Sporadic-E propogation was coming down in a small area of France and there alone.
At around 13:00, the band began to open up again with a weak Italian CB station making an appearance. Back up to check the beacons and the French beacon F5ZWE in JN02tw makes an appearance on 28.243.0 MHz. It peaks at 529, not too strong but it was still the strongest beacon heard today. It is also seems, like yesterday, to be one of the most persistent as when I check back 30 minutes later, it is still there although it was bwginning to fade at that stage. I also had a listen for the C30P beacon as it is in the same locator square. It was audible when it made it's appearance but pretty weak.
After about 13:30, the signals faded out on 10 metres but the CB band seemed to be busy with weak Spanish stations for at least another 2 hours.
Overall today, the CB band stayed open longer but the signals on 10m and 11m were a lot weaker. Yet again, all signals seemed to be due to Sporadic-E propogation.
On a side note, I also heard a CB station from near Thurles in Tipperary on tropo. His signal was around only about 4/1 but at a distance of around 100 kms, it suggests that this old CB half wave may not be so bad after all.
For the record, the solar flux was at 71 today, no real change from last week.
Thursday 13th November 2008.....
The band opened up today just after 10:00 UTC. Some CB stations from Luxembourg and Sweden were heard around 10:20. That was the first time that I had heard a Scandinavian country this month. Checked the 10 metre band also and the following beacons were heard over the next hour....OE3XAC (JN78sb), DL0IGI (JN57mt), LA4TEN (JO28wl - 1160 kms), LA5TEN (JO59jp near Oslo), DK0TEN (JN47nt), SK5AE (JO89kk) and SK0CT (JO89xk). After this (11:20), signals began to fade. It was almost as if the band had been open but the the MUF was only high enough to support propagation to 2 areas....1) the Southern part of Norway and Sweden and 2) the southern part of Germany.
11:40..the German beacon DM0ING (JN49ax) makes an appearance. The French beacon F5ZWE (JN02tw) shows up as well indicating that the band is opening towards the South-East as well.
11:50...with the exception of a few weak beacons and some weak French CB stations, both 10m and 11m sound very quiet. A beacon from North Germany is heard....DB0UM in JO73ce, only 4 watts into a vertical!
12:04....the LA4TEN beacon is still there. It has been in and out for around 90 minutes.
12:10...another French beacon, F5ZUU in JN24il with only 5 watts to a vertical, F5ZWE is still sounding well (519).
12:20...the band begins to open up further South with EA4Q (IN80wc) in Cuenca near Madrid.
12:50...the F5ZWE beacon is now peaking 549, the strongest beacon all day. Considering it is in the same locator square, I tune and wait for the Andorran beacon C30P..it appears albeit weakly.
Bands seem quiet though and the propogation moves back East again...OE3XAC (419) and DM0ING show up. On SSB, DB1NT is heard.
13:40...check the CB bands...very quiet.
13:45...F5ZWE/B is back again!! What a great little beacon! After that, things fade away until around 15:00, both 10m and 11m seem dead.
I later found an interesting map which shows most of the beacons above.
18:30...check the DX-cluster and notice that EI2IP spotted a strong PY (Brazil) station around 17:30. Would I have heard it if I was here??? I doubt it as I have a hill in that direction. I have often seen that before on 6 metres and on 10 metres....anyone here on the South coast of Ireland seem to be able to exploit openings to South America when the band appears dead. It's almost as if the signals are coming in at an extremely low angle. Any hills in the way or if you move inland, you lose access to these openings.
Friday 14th November 2008.....
Band opened up around 10:30 with some very weak CB stations on 11m. Checked 10 metres and heard a very weak beacon just below 28.2 but was unable to ID. In the next 10 minutes, I heard a CB station from France and one calling himself 20ET??? which would suggest Norway?!?! If it was, it was the only signal I heard that far North all day.
10:47...The French beacon F5ZWE/B makes an appearance with a good 529 signal. A few minutes later, C30P appears. Also heard is a weak CB pirate on 28.235 MHz :o(
11:10...EA4Q near Madrid appears with it's 5 watts into a ground plane antenna.
11:20...Spots on the DX Cluster suggest that the EA4Q beacon is been heard near Berlin and in central Italy. This would suggest that Sporadic-E region is over France and to the South of it also.
11:30...The French beacon F5ZWE/B is still there but soon fades as the propogation becomes mainly from the South.
12:00....and 12:30....the EA4 beacon is still there, by far the most consistent beacon of the day.
13:00...I see a G3 station in England spotting some CT beacons on 50 MHz. I tune around (...with my CB half wave!) and heard CT0SIX weakly in IN51ne on 50.031.7 MHz.
13:20 and 13:55...EA4Q/B still going strong at 519.
14:14....Portugese CB station heard.
Not long after that, the band begins to close. Open for about 4 hours and mainly from the South to South-East.
Saturday 15th November 2008.....
Around 10:15, I started hearing some CB signals on 11 metres, all very weak. Around 10:26, I checked the DX Cluster and noticed that EI2IP (~40 kms to my North-East) had spotted IT9BLB in Sicily on 28 MHz SSB with a 5/9 signal at 10:06! I listened on this frequency (~10:28) and I could hear a very weak signal. Did the signal fade?....or was it that I just wasn't hearing it??? When I first saw the spot, I thought....Sicily on 10m at 5/9 = F2 propogation. But, it didn't fit.......1) Solar flux is down around 70 anddirect F2 from this latitude is unlikely 2) If there was F2, I'd have expected something further away, out around the 3,500 to 4,000 kms mark like TA or 5B4. Sicily is about 2,400 kms from here and angle of radiation for F2 propogation would be around 8 degrees. Most of the signals that I have been hearing recently on Sporadic-E are around 1,500 kms away which would suggest that they are coming in around 4 degrees. How come I wasn't hearing signals at 8 degrees elevation???
So, I had a look at the map again...the North-West corner of Sicily might be at the limit of 1 hop Sporadic-E. Checked out IT9BLB on the net and sure enough, he was located in Palermo on the North West corner of Sicily!! The signal that EI2IP had heard was practically near the limit of 1 hop Sporadic-E. It was coming in at an extremely low angle, probably 1 degree or less. Perhaps the signal had faded by the time I tuned in???........but I doubt if I would have heard it anywhere near as well with a vertical half wave only 4 metres above ground level and with obstructions in that direction.
It's a good reminder that 10 metres is almost in a way, the lowest VHF band. You have to get those aerials up high and in the clear so that you will have a low angle of radiation. To work serious DX on 10m, you need to exploit those low angle signals.
So, back to today...12:07...heard some Spanish CB stations on 11 metres. Overall, just bits and pieces but nothing consistent. I saw a G station spotting V51AS (Namibia) on 28 MHz SSB. I listened....I could hear something extremely weak, maybe 2/1 max. Then all of a sudden he came out of the noise...4/1 calling QRZ...I called him...nothing...and I mean nothing, he was gone. Did he turn off?? It was strange how he got so strong all of a sudden.
I began to wonder if it might not be a meteor burst that enhanced his signal between EI and say EA and then on to the F2 propogation? I know the Leonids meteor shower is supposed to peak next Monday and there are supposed to be increasing number of meteors from the 14th onwards. To check the meteor theory, I tuned to the frequency of the LA4TEN beacon that was a nice signal 2 days ago. I had heard nothing that far North today and I might hear some bursts. As soon as I tuned in though at 13:42, there it was! Very weak, about 2/1 but I got enough parts of the call for a positive ID. Meteor Scatter or Sporadic-E??? Who knows...
Certainly down on the CB bands today, I have heard bursts of signals which sound English and sound like they might be meteor scatter. Next Monday might be interesting...
Sunday 16th November 2008.....
I was missing for a lot of today. I see that an EI station spotted V51AS on 28 MHz cw so there must have been some Sporadic-E and F2 about to the South.
Monday 17th November 2008.....
First a general report....I had the radio on in the background and as far as I could tell there was no Sporadic-E all day. The DX Cluster was also very quiet.
Since today was supposed to be the peak for the Leonids Meteor shower, I had a listen this morning for 1 hour between 08:35 and 09:35 on 28.215.1 MHz for the GB3RAL beacon. I heard several pings and a very long burst but the signals were very weak and I was not able to get a positive ID. I sent an e-mail to someone about it so hopefully they can confirm what I heard.
Down on the CB bands around 10:00, I heard some evidence of some nice meteor scatter signals. One CB station in Cambridgeshire (5/7) mentioned that conditions were "very sporadic" ;o)....in other words, the signals were up and down. Also heard on 27 MHz ssb was someone mobile (5/3) on the M25 around London. I presume most of the CB stations just thought it was 'good skip conditions' without realising that their signals were coming off meteor trails left in the upper atmosphere!! I heard a few French CB stations as well but most were of short duration. Probably due to meteor scatter rather than Sporadic-E.
Tuesday 18th November 2008.....
Today was pretty dead on 10 and 11 metres. I heard bits of European signals on 11 metres but nothing much. I listened for the GB3RAL beacon again this morning and heard a few pings.
Wednesday 19th November 2008....
Real sunspot minimum stuff where 10 metres sounds more like 2 metres than a HF band. Bit's of Europeans heard on 11 metres. I heard one strong Swiss SB station but when I scanned around...nothing! Might have been just a meteor burst.
Thursday 20th November 2008....
Even quieter than yesterday.
Friday 21st November 2008....
Missed today. There were a few spots on the cluster for English stations so maybe the 10 metre band was open?
Saturday 22nd November 2008....
Weak opening for about 30 minutes around 11:30. Heard a few CB stations on 27 MHz, sounded French. On 10 metres, the band was open from here (Cork - IO51) to the South of France. Heard F5ZWE/B and C30P in JN02. Max 419.
Sunday 23rd November 2008...
I missed today. However I noticed that on the DX Cluster, Robbie EI2IP who is about 40 kms away had spotted several beacons in LA, SM, DL, OK. Even though I am only using a half wave, it's probably safe to say that I would probably have heard something and should count this day as an active one.
Monday 24th November 2008...
Missed today. Cluster looked pretty dead anyway.
Tuesday 25th November 2008...
Another dead day...
Wednesday 26th November 2008...
Very short opening today. 10 metres and 11 metres opened for about 30 minutes.
10:55....heard some weak CB stations in North France and Poland on 27 MHz.
11:04....heard the German beacon DB0UM in JO73ce on 28.278.7 MHz. Pretty weak, maybe 419 max. The mid point of this path was somewhere over ON/PA (Belgium/Netherlands). What was interesting was that a few minutes late, F5TMJ in the South of France spotted the SK5AE beacon in Sweden. The mid point for his path was roughly the same as mine. You often get this on 6m metres and 2 metres where there is one Sporadic-E hot spot and the propogation paths resulting from it are like spokes of a wheel.
11:25...bands dead again.
Thursday 27th November 2008...
Turned on at 10:00 and there was a weak opening in progress. Judging by the DX Cluster, it wasn't open too long anyway beforehand, maybe 20 minutes?
10:00 Heard weak Italian CB stations on 27 MHz.
10:19 Hearing weak French CB
10:40 Hearing the French beacon F5ZUU on 28.241.4 MHz. Signal is weak...perhaps 319 to 419 max.
11:15 Band has closed again. Nothing on 27 or 28 MHz.
The opening today was typical of what I have heard this month....band opens for maybe 2 hours or so, signals are weak. However, it was a bit unusual in that it seemed to open earlier than usual.
Friday 28th November 2008...
Dead quiet today.
Saturday 29th November 2008...
Today was the first day of the CQWW CW contest. It's amazing that when there are high powered stations constantly transmitting, every possible propogation path shows up. As a result, today was unusual in that while the CB band appeared dead, 10 metres sprung to life. Perhaps 'sprung' is a bit of an over exageration in that what was spotted on the DX Cluster made it obvious the limitations of using a CB half wave vertical antenna at only 4 metres above ground level.
11:25...The band opened for me with some Sporadic-E to the South. The Spanish contest station EE2W was heard very weakly, perhaps 419 max. It was obvious from the cluster that with a better antenna at a greater height, I would have heard a lot more.
12:10...The French beacon F5ZUU in JN24 was heard at around 319. At much the same time, EI2IP about 40 kms spotted a Portugese beacon at 599. Nothing audible here. South is a direction in which my local hill begins to get nasty. Again, more height on the antenna would have made a big difference.
Other than that, I was really hearing nothing other than the contest station 3X5A buried in the noise. From the snippets I was getting, I could tell that he was not too busy with plenty of CQ Contest calls. Just left the rig on the frequency while I worked away on something else until about 12:29, he popped up out of the noise to a 549. Quick call, quick exchange and 3X5A was in the log. And sure enough, he started to fade back down into the noise again. Other than that, nothing else was heard although stuff was getting spotted on the DX Cluster by EI and G stations. Todays lesson.......like 6 metres, you really need a beam and /or a good site to fully exploit openings on the band.
Sunday 30th December 2008...
I listened during the morning until 12:00. Even though the contest was in full blast, there wasn't a signal here on 28 MHz. Even the cluster didn't suggest that the band was open anywhere else in the UK or Ireland. When I checked again around 16:00, the cluster suggested that the band had opened during the early afternoon. Would I have heard anything???
So, what to do to get back on air? Most of my aerials have blown down or suffered some damage in the last 3 years so I am basically starting from scratch again. But what aerials to put up? What bands? My first priority was just to put up something to get me back on the air again, nothing too fancy ;o)
About 20 years ago when I first got on HF, my favourite band at the time was 10 metres. It's a band that has properties of both HF and VHF propogation and I used to be very active on it. I had an old CB aerial that was given to me years ago and which I used for a small while in the mid 90's. So, that was the obvious choice to get me going again.
Looking at the lenght, it seems to be an end fed half wave i.e. approx 5 metres long with a matching coil in the base. There is no name on it but I presume most of these aerials are much the same. The only question mark I have about it is whether there is much loss in the base matching coil? I seem to remember when I changed this aerial (half wave) for a multi-band vertical (Cushcraft R-6000)(3/8 wave) a few years ago, my signal on 10 metres improved a lot?
Perhaps I was mistaken but I still have my doubts about whether this type of CB aerial is a good performer.
So, at the start of November 2008, I mounted the CB half wave on a 4 metre pole and fed it with Westflex 103 coax. Why only 4 metres??....it just so happens that I have a pole that lenght and by having it that low, it reduces the wind load on the aerial.
Looking at the VSWR readings that I was getting, it would seem as if the 1:1.5 VSWR bandwidth was about 700 khz. I adjusted the lenght so that the lowest VSWR which seemed to be 1:1.2 to 1.3, was near 28.300 MHz.
This put the upper 1:1.5 VSWR limit up around 28.650 MHz and the lower one was probably down around 27.950 MHz although I had no way of confirming this. By selecting 28.300 MHz as the midpoint, it meant that I could still cover most of the SSB part of the band, the CW section is really good and the VSWR down on the CB band is still reasonable so that will be useful for listening for propogation indicators down there. Looking at the 2:1 VSWR bandwidth, it probably goes from 27.7 MHz to 29.0 MHz, around 1.3 Mhz.
Comparison...Old aerial V Sirio Half Wave
The old CB half wave looks pretty similiar to the Sirio GPS27 1/2 as seen on this website. That site suggests a minimum VSWR of 1:1.2, a 1:1.5 VSWR bandwidth of 0.75 MHz and a 1:2 VSWR bandwidth of 1.35 MHz for it's antenna. Those figures look very close to the readings that I got for my half wave.
The above VSWR readings were taken with the meter built into the Kenwood TS690 transceiver. When I placed an external VSWR meter in line, I got similiar readings. The strange effect was that the VSWR now as seen by the rig was a lot lower. In fact, from 28.0 to 29.0 MHz, the VSWR stayed around 1:1.1. It was almost as if by putting the external VSWR meter in line, it was helping to match the aerial to the rig. Almost like an ATU!! Strange...
The first good sign is that the aerial is picking up lots of noise so it must be working in some sort of fashion. There seems to be a constant S '3' noise level on AM so perhaps this isn't the quietest of radio locations. Certainly, it picks up a fair bit of noise from the PC which is about 8 metres away.
Listening to the CB band, there seems to be very little activity locally. I can hear a few weak CB stations on SSB at night but due to the absense of proper callsigns, it's difficult to say how far away they are. I heard one mention that he has in Rathmore, Co.Kerry which is about 50 kms away on the far side of the Boggeragh Mountains so perhaps this aerial is not so bad after all?
Another unusual feature of the local CB band is that the churches use it to broadcast the mass service to elderly or sick people who are unable to travel to church. There seems to be several of them...
27.065 MHz...FM...S '3'...Location?
27.305 MHz...AM...S '1'...Location?
27.325 MHz...FM...S '4'...Location?
27.525 MHz...FM...S '4'...Location?
27.595 MHz...FM...S ' 6'...Location?
27.605 MHz...FM...S '7'...Location?
27.615 MHz...FM...S ' 1-2'...Location?
27.625 MHz...FM...S ' 6'...Location?
27.675 MHz...FM...S '9+40dB'.....Glounthaune, East Cork.
I have them listed here with their signal strenghts on AM as they might be useful as local signal sources. That way, if I change aerials, I can do a comparison and see if there is an improvement or not.
I had a quick listen on 6 metres with this aerial and I was suprised to hear the EI beacon EI0SIX on 50.051.66 Mhz (20w & Half wave vertical)(IO63nf). This beacon is approx 180 kms to the NNE from my location here in Cork. Considering the matching coil at the bottom of the CB aerial, I would have thought that 50 MHz would have been filtered out? It doesn't seem so although as expected, the VSWR is pretty high.
The beacon is about 419 in signal strenght although it does vary slightly, almost as if there is a slow variation in tropo conditions over the 180 km path. It peaks around 519 and goes as low as 319 but is always audible.
So that's it, I'm back on the air and on 10 metres again....