Thursday 31 July 2014

Russian TV...6m's Little Helpers

London's Crystal Palace TV Tower
Further to my recent blog regarding the rare West Coast to Europe 6m summertime events, the biggest challenge has always been trying to predict when propagation might be building in that direction. Before most European TV transmissions switched from analog to digital mode several years ago, the best 50MHz propagation indicators were the vast numbers of high-power low-band video transmitters blanketing the Continent.
Parked conveniently close to 6m, the 49MHz multi-kilowatt transmitters combined with large high antennas to pump lots of ERP over the pole. Surprisingly, there are yet a few holdouts of the analog era that are still available as propagation indicators, with most of them being located in western Russia and the middle-east. Far eastern Russia also has a number of the analog relics in Siberia and in the Vladivostok / Kamchatka regions, all of which which make great indicators for possible openings to Japan, China and Taiwan. During good openings to Japan, it is not unusual to hear several different signals all on the same frequency but with different fade rates and tone / sync characteristics. During the past few strong solar cycle peak years, spurs from these Russian  transmitters could often be heard at S9 levels well into the 6m band!

Although there are numerous others, from my own experience the best frequencies to monitor for both European and Asian transmitters have been:

  • 49.750
  • 49.757.8
  • 49.760.4

During Sunday's VE6-Europe 6m opening, several of these signals were heard even though no Europeans were worked from the west coast. Video carriers on 49.750, 49.760 and 49.757 were heard for over an hour, peaking around 1800Z.

The two unique characteristics of these video markers has always been their rapid fade rate and their somewhat raspy video-sync pulses....both can be heard in this short video that I captured during Sunday morning's activity. The stronger 49.757 signal can be heard as well as the weaker 49.750 carrier, while the 49.760 signal has taken a deep fade. I suspect that the louder signal is coming from the Novosokolniki transmitter north of Moscow while the weaker ones may be further to the south. These locations are simply 'best guesses'.

This recording of eastern Russian video carriers, made by JM1SZY, provides a good idea of how these signals sound when they're much stronger. Note also, the number of different frequencies that the different transmitters are using.

It is very difficult to know exactly where the actual transmissions are coming from as there are dozens of transmitters assigned to the same frequency. Most signals do vary from their assigned frequency by measurable amounts and some avid DXers have tried to identify individual sites by accurate frequency measurements.

Since the digital switchover, interest in keeping track of the remaining signal data seems to be falling off and most frequency and location lists are now several years out of date. The most up-to-date lists can be found here on the GØCHE Website and on JB's DX Info site in Germany.

If you're anywhere east of the Great Lakes then you'll hear the European videos a lot more often than they are heard out west but it still astounds me that several times each summer, I am able to hear TV signals from Europe over the North Pole!


PE4BAS, Bas said...

Hello Steve, this is very interesting information. I never knew TV carriers are sounding like this. I'll listen on 6m if I can hear them. 73, Bas

Steve McDonald said...

You should hear the western Russians ones or those in Belarus, Ukraine etc. They will be loud on Es for you I think and probably can be heard well on meteor scatteralso.