Showing posts with label TVDX. Show all posts
Showing posts with label TVDX. Show all posts

Monday, 24 October 2011

Radio Meteors - Ostrava R1 Gone?

Sorry it has been a while since my last post, lots of stuff going on, not much of it worth blogging about!

However, I am moved once again to note the possible loss of my present (up until now, at any rate) source of Radio Metor Reflections, the TV Transmitter serving Ostrava in the Czech Republic on channel R1. (49.76MHz).

I tried to tune in over the weekend to pick up any Orionid meteors, only to be met with wall-to-wall white noise.

It's an even greater pity, as this is (or was) the last broadcast TV source I could receive on Band I.

I had reported previously that this transmitter was due to close in November, but either this has happened early, or the transmitter is off due to a fault or maintenance.   If I were in charge of a transmitter which is just about to close down, I don't think I'd spend too much effort on maintenance, but you never know!

As of the time of writing this entry, I haven't been able to verify what has happened, all I know is, I have no Orionid trails on my PC!

Interestingly I found a web site by Czech radio amateur Ivan OK2BMU who is waiting patiently for that same transmitter to close down so that he can get cracking on the amateur 6m (50MHz) band!  Every cloud has a silver lining, as they say ...

Sunday, 1 May 2011

First Es (Sporadic-E) Opening of the Season

My radio friends know that I spend a lot of energy (mental and electrical) monitoring distant Band I TV stations looking for and recording the effects of meteors on the propagation of signals between that remote transmitter and myself.

A side effect of this is that when Sporadic-E (Es) propagation occurs at the critical point along that path, the effect is obvious.

I was only commenting to two local friends two days ago that this year's Sporadic-E season seems to be late in starting, and my friends were in agreement with that statement.

This morning's events though took an interesting turn at 0906 GMT when the path from Ostrava in the Czech Republic was suddenly enhanced by a burst of Es which lasted for around ten minutes.

The frequency used by the Ostrava TV transmitter is 49.76MHz, just below the amateur "six metre" allocation.


(above) R_Meteor Trace of first Es Opening

SpectrumLab Trace of Es Opening (note +/- 25Hz Sidebands)

By a bizarre coincidence, as I type this entry, I have just heard a Spanish station EA3FER calling CQ in CW on 50.092MHz and shortly after another Spanish station, this time an EA6 call from the Balearics, so it appears that the 6-metre Es season has finally started!

Sunday, 24 April 2011

Band I TV and Radio Meteors - the End is Nigh!

I have blogged a couple of times already about the disappearance of VHF analogue TV in Band I, today I came across a little more information about the demise of the few remaining sources available to we "Meteor Reflection Enthusiasts".

It seems the Ostrava (Czech Republic) transmitter on channel R1 (49.76MHz) will close on 30th November 2011, and the Lousa (Portugal) transmitter on channel E3 (55.25MHz) will close on 26th April 2012, in almost exactly a year's time.

Spectrum Lab Capture of Metor Burst

Quite what, if any signals will be found for displaying meteor reflections once these disappear, I know not, but in the meantime I have resolved to make some audio recordings so that the use of the audio software I use (R_Meteor, SpectrumLaboratory, etc) can be demonstrated should anyone show any interest!

R_Meteor Capture of above SpecLab event

Amateur signals such as beacons are too low in power to fill the gap.   Maybe some QRO beacons are required?   Not very "green", though!

Friday, 18 February 2011

Deep Joy! A New (to me) source of meteor pings!

Tonight, courtesty of a link I found on Andy Smith's excellent TVCOMM web site, a really good list of current Band I (and other) frequencies in use, one of which is used by the Czech Republic. The transmitter is located near Ostrava, and runs at 100kW ERP.

I reckoned this to be a good distance for meteor reflections, so I tuned in my receiver and listened for a while, and, yes, I thought I heard the sound of meteor activity.

On came the software to track it down (first Spectrum Laboratory for a wide sweep, and then R_Meteor for a narrower sweep centred on a 1kHz beat note), and, yes, the unmistakable traces of meteors.




Now for the bad news - according to the link I referred to, this transmitter closes this November. But until then, I well keep looking!

The frequency I am monitoring, in case you are interested is 49.75949MHz, on my FT-920 which does not have any kind of precision frequency standard, just usual bog-standard crystal reference for the synthesiser. (Don't forget, this is offset from the "true" frequency by 1kHz so that the audio spectrum analyser based software works properly)

As you can see from the image above, I am getting LOTS of pings.

Monday, 8 March 2010

Band I TV - Liege E3 - R.I.P.

Well I've known it's been coming, but today I have finally realised that one of my "favourite" sources of meteor reflections, the Band I TV RTBF-1 transmitter on Channel E3 near Liege (Belgium) is no more.

It was there the last time I checked last month, but today, having a day off work when I though I would just have a little tune around to see what was going on, I received no signals from that transmitter. Fearing the worst, I did a Google search and found out very quickly that the transmitter was turned off for the last time on March 1st.

The YouTube link in the heading points to a recording of the last minute or two of programme from this transmitter.

I expect the equipment is going to be dismantled and be recycled into razor blades or whatever, such is the fate of electronic equipment once it has ceased to be of use.

This transmitter not only was the source of meteor reflections, but its distance from me made it ideal to display the effect of aircraft reflections. I have captured many "waterfalls" of these phenomena.

Now that the digital TV bandwagon is rolling relentlessly through Europe, it's only a matter of time before the remaining Band I TV signals are quiet forever. Digital TV will never be broadcast on Band I, so there isn't even that prospect to look forward to.

On the plus side, as these TV services close down across Europe, it appears that more countries are acquiring Amateur allocations in the 70MHz region. As I will hopefully be joining the ranks of 70MHz users in the future, once my homebrew 70MHz "Eden9" transceiver is up and running, that is a bonus.

R.I.P. RTBF-1 Liege, E3