Saturday, March 31, 2018

Daytime band scan on Medium Wave using basic domestic radios...March 2018

After a recent chat with Willie EI7CGB about Medium Wave reception, I did a daytime band scan to see what could be heard on the band using just basic domestic radios. I used two radios....

Silvercrest KH2030...The first one is a Silvercrest radio which I picked up in Lidl a good few years back. I think at the time, it was only about €18 and it's performance can be at best be described as mediocre. It's fine for listening to local stations on FM but on AM, the sensitivity is poor. At night, it can pull in the strong European signals but it's not very good for weak signals. It does however have a digital readout to show what frequency it is on.

Sony CFS-W360L... The larger radio is an old model which covers FM, Medium Wave and Long Wave. Considering its size, it probably has a bigger internal ferrite rod aerial for Medium Wave than the Silvercrest and as a result is better at hearing weak signals. The tuning dial however is analogue but that wasn't too much of a problem when there are only a small number of signals to hear during the daylight hours.

The tests were done in the middle of the day when only ground wave signals would be heard. This is what was heard.

Freq KHz Station Distance (kms) Pwr (KW) Location Notes
549 Spirit Radio 280 25 Carrickroe, Monaghan Nothing on Silvercrest. Very noisy on Sony. Positive ID due to local signal on VHF.
630 BBC Radio Cornwall 280 2 Lanner, Redruth, Cornwall Noisy on the Silvercrest. OK to ID. A good bit better on the Sony. Noisy signal.
657 BBC Radio Cornwall 300 0.5 Bodmin, Cornwall Very weak on Silvercrest. Strong enough to ID on Sony but difficult to make out what is being said. Very noisy on Sony.
693 BBC Radio 5 Live 370 50 Start Point, Plymouth, Dorset Assume it's Start Point S coast of Devon. Noisy on Silvercrest. Reasonable but noisy on Sony.
756 BBC Radio 4 R3-4 2 Lanner, Redruth, Cornwall Noisy on Silvercrest. Reasonable but noisy on Sony.
801 BBC Radio Devon 300 2 Barnstable, Devon Noisy on Silvercrest. Reasonable but noisy on Sony.
882 BBC Radio Wales 470 100 Washford, Somerset, England Noisy on Silvercrest. Reasonable on Sony. Seems to be one of the strongest signals.
909 BBC Radio 5 Live 380 50 Clevedon, Somerset Noisy on Silvercrest. Reasonable but noisy on Sony.
990 BBC Radio 5 Live 300 1 Tywyn, near Aberstwyth, W Wales Hardly anything on Silvercrest. A very noisy and weak signal on the Sony.
1089 Talk Sport R2-3 2 Washford or Redruth??? Noisy on the Silvercrest. OK to ID. A good bit better on the Sony. Noisy signal.
1215 Absolute Radio 470 100 Washford, Somerset, England Noisy on Silvercrest. Reasonable but noisy on Sony.

1) A total of 11 signals were heard. Roughly 7 of them were strong enough to listen to but with a good bit of noise. The other 4 were weak.

2) The 657 KHz signal from the 0.5kw BBC Radio Cornwall transmitter at Bodmin was about the same level as the 25kw Spirit Radio transmitter up in Co.Monaghan on 549KHz. Considering that both are roughly the same distance from here, it just goes to show the difference a sea path makes even though I am still about 20kms inland.

3) I repeated the test on several days at about the same time, the results were the same. These are the basic 11 signals that I can hear from my house.

The equipment used was very basic and would be pretty typical of what most people would have. It does however set a useful base line on which to judge future tests and improvements.

Saturday, March 24, 2018

Donations for the Southern Ireland Repeater Network

The Southern Ireland Repeater Group maintain an impressive repeater network in the south of Ireland. They have no fewer than 7 voice repeaters scatted across the 2 metre and 70cms bands as well as two digital repeaters in Waterford.

While VHF and UHF activity remains at a low level, this network is largely responsible for much of the activity on the higher bands.

I noticed recently that they have added a donate facility on their website to help maintain the network. Have a look if you wish to contribute....

Friday, March 16, 2018

Hearing the Mt.Leinster 70cms repeater at 135kms on a handheld

While I was updating the code plug for my TYT MD-380 dual mode handheld, I decided to add the Mt.Leinster repeater EI7MLR on 430.950 MHz. Initially, I thought it might be interesting to see if I could hear it under lift conditions. Little did I realise that I can actually hear it all the time with the half-wave whip on the handheld just sitting next to an east facing window.

Mt.Leinster is 135kms or 84 miles from my location, quite a distance for a UHF signal. I have heard the repeater before on my main rig using a home made colinear in the attic but only under lift conditions.

The signal I am getting on the handheld is under flat conditions and it's steady... about a constant 4/1. Pretty amazing considering the distance.

The profile of the path is interesting...

Right in the middle of the path is the Comeragh Mountains at about 750m above sea level (asl). I can see these mountains from my house 40 miles away on a clear day and obviously the path from Mt.Leinster at about 780m asl to the Comeraghs is line of sight as well.

It does raise some interesting points.....

1) I tried using the handheld in the attic and I seem to hear Mt.Leinster just as well in the attic as I do at the upstairs window. I would have expected that the roof tiles would have attenuated the UHF signal more.

2) I am not hearing Mt.Leinster on my main rig with the home brew colinear in the attic. I think it might be worth trying to put up another 70cms antenna in the attic? Perhaps the colinear isn't working as well as I thought.

3) In the past, I would have considered any type of mountains as a bit of a show stopper. I found out a long time ago that if the mountains are far enough away, they are less of a problem on VHF and UHF.

Tuesday, March 13, 2018

80 year old US radio amateur rescued from 20ft tower

It sounded a bit like an April Fools joke but this headline is doing the rounds at the moment. An 80-year old radio amateur in the USA had to be rescued from the top of a tower which was a mighty 6 metres high. Apparently the trouble started when his shoe got stuck.

As you can see from the photo, there was no shortage of firefighters. Must have been a slow day in Edgartown.

Full story HERE

Saturday, March 10, 2018

Snapshot of DMR activity in EI - 10th March 2018

After a few contacts earlier today on digital radio (DMR), I began to wonder what the DMR activity levels in Ireland was like among EI calls. After a small bit of digging, I came up with some stats which are current as of the 10th of March 2018.

Some stats...

1) 108 DMR numbers...There are 108 registered DMR numbers issued to EI calls. Even though number 272109 was issued, number 272008 is that's 108 in total.

2) 100 Individuals (incl 3 clubs)... Eight individuals have two DMR numbers a) EI9IL/EI1UN b) EI3JE c) EI4GJB d) EI4KN e) EI5CA f) EI7IG g) EI8EJB and h) EI9ED. So that makes 108 - 8 = 100 individuals with registered DMR numbers. (Three are clubs but I'll count those as individuals).

3) 46% Heard... Out of the 100 individuals registered for DMR, only 46 have been heard. (49 - 3 duplicates from EI3JE, EI4KN and EI7IG). If that's correct then that means 46% of the those that have registered a DMR number have actually activated it.

4) 41 active in 2018...Of the 46 heard, a total of 41 of these were heard in the first 10 weeks of 2018. That probably represents the current number of EI calls actually active at present on this digital mode.

5) Distribution of activity... Of the 41 heard in the first ten weeks of 2018, this is where the majority were heard last...(as of the 10th of March 2018)...
...a) 21 heard on MMDVM individual hotspots.
...b) 7 heard on EI7WCD in Tramore near Waterford City.
...c) 7 heard on EI7CDD in West Waterford.
...d) 2 heard on EI2GCD in Galway City.

6) Registrations by County... If we count the club calls and account for those with two DMR numbers, this is the breakdown by county (3 and more)...

It breaks down as Cork 14, Galway 13, Waterford 8, Limerick 8, Dublin 6, Louth 6, Clare 5, Mayo 5, Wexford 4, Donegal 3, Tipperary 3, Kerry 3 and Kildare 3.

7) DMR Registrations by Quarter... The chart below shows the total number of registered DMR users in Ireland (EI) at the end of 2017.

It's worth pointing out that the stats above don't show the large pocket of activity in Northern Ireland as well (GI).

Taken all together, there are three pockets of activity in the south-east near Waterford & East Cork, near Galway City and in the north-east near Belfast.

It's amazing there is no real activity yet from near Dublin? Why?

1) EI registered DMR numbers

Wednesday, March 7, 2018

Line of Sight to the DMR repeater EI7CDD

After a spell of four years off the radio, I got on air again in late 2016. Once I came back, I found out there were some new developments in the world of digital radio with D-Star, Yaesu System Fusion and DMR. I read up on these but at that stage at the start of 2017, there were no digital repeaters anywhere near me in Cork.

After another short spell off the radio from May to December 2017, I found out in January of 2018 that a new digital repeater with the call sign EI7CDD had been installed in West Waterford in September of 2017.

The new repeater was located on a 300m high hill called Carronadavderg in West Waterford which just so happens to be line of sight to my house!

Carronadavderg is high enough so that it is visible for me over the hills to the north of Killeagh. The repeater is 45kms / 28 miles away.

On any sort of clear day, I can see Carronadavderg on the horizon. This is a photo I took today with a small telephoto lens on the camera. The golf course in the foreground is about 2-3kms away.

The white below the summit of Carronadavderg is a layer of snow while the darker summit is covered in trees.

On closer inspection, some white microwave dishes can be barely seen on the summit when the sun was shining there. The houses in this view are some 25kms distant.

The view was a little better when the dark masts were contrasted against a bright background. I can pick out six masts in total...three large ones and three small.

Pretty amazing what the camera could pick up from 45kms away!

The main thing of course is that it is line of sight from here which allows me to access the DMR repeater with 1w from a TYT MD-380 handheld with a whip antenna.

When I check the Last Heard list for EI7CDD, I seem to have a signal of S4-6 when I stand next to a window here in the house so I can get into the DMR system fine.

Sunday, March 4, 2018

IRTS Membership Stats...End of Dec 2017

In the most recent newsletter from the Irish Radio Transmitters Society (IRTS), they stated that there was 927 members in the society at the end of 2017. I had a look at the previous membership levels and I put together this chart...

As the chart shows, there was four years of decline from 2009 to 2013 but it has leveled out since then. While the chart may look pretty dramatic, the range from the highest to lowest point is in the region of 8.5% so it's not huge. In the last decade (2008 to 2017), the IRTS membership has declined by 5.8%.

Another interesting stat from the newsletter is that there was 1729 EI call signs at the end of 2017. Back at the end of the year 2000, it was 1726...almost identical. I suspect that a lot of people would have expected the number of EI call signs to have dropped since the start of the new millennium but that doesn't seem to be the case.

One worrying aspect is that the number of EI calls that are members of the IRTS is dropping. The chart below shows that 44.9% of all EI callsigns are members of the IRTS as of the end of 2017.

Considering that the IRTS membership has dropped since the year 2000 and the number of licences is largely the same, the overall percentage of EI calls who are members must have dropped.

As it says on the IRTS website..."IRTS is the national society for radio amateurs and experimenters in Ireland.  Its purpose is to promote the study of radio communications, to encourage radio experimentation and to provide services to its members."

It would be nice if more people with licences supported what is an organisation run by volunteers on behalf of its member. €30 per annum is a very modest fee.

1) IRTS website