28-06-2020, 05:18 PM
You mean VHF 40 MHz to 70 MHz? Biggest interference that high is so called Ethernet over mains. In reality ultra wideband transmitters. The fastest ones probably create interference above Band II, Air Band. SMPSUs and Electronic Ballasts are hitting LW, MW and lower SW bands.
I do remember Band I TV 405 TV and the occasional evil vehicle. I did repair and sell some 405 TVs in 1971 as second sets. We actually had 625 Line Band I TV after we moved to Limerick and Clare in 1983. Never ever 405 in those areas, the Irish 405 closed about the same time as UK, in maybe 1985 and was only for areas that picked up UK TV in the 1950s. The local UHF only mast for Limerick City was later. The Band I TV on 625 closed about 1999 here, replaced by a mix of Band III and UHF. Analogue closed in 2012 only four years after DVB-t + H.264 trails started. All the SD channels used 264 from the start, so only imported UK TVs with HD DVB-t2 worked at all. Criminal levels of imports and sales of UK TVs from 2010 to 2013 that could only work as a monitor on a setbox.
VHF FM band II should have been extended with OIRT 65.8 to 74.0 and Japan 76-95, giving 65 to 88.5 extra instead of DAB, which is now obsolete duplication of DVB-t.
I think 42MHz, 50MHz and 70MHz approx are now Ham bands. I've not noticed any significant noise on 50MHz SSB with a roof top aerial
I do remember Band I TV 405 TV and the occasional evil vehicle. I did repair and sell some 405 TVs in 1971 as second sets. We actually had 625 Line Band I TV after we moved to Limerick and Clare in 1983. Never ever 405 in those areas, the Irish 405 closed about the same time as UK, in maybe 1985 and was only for areas that picked up UK TV in the 1950s. The local UHF only mast for Limerick City was later. The Band I TV on 625 closed about 1999 here, replaced by a mix of Band III and UHF. Analogue closed in 2012 only four years after DVB-t + H.264 trails started. All the SD channels used 264 from the start, so only imported UK TVs with HD DVB-t2 worked at all. Criminal levels of imports and sales of UK TVs from 2010 to 2013 that could only work as a monitor on a setbox.
VHF FM band II should have been extended with OIRT 65.8 to 74.0 and Japan 76-95, giving 65 to 88.5 extra instead of DAB, which is now obsolete duplication of DVB-t.
I think 42MHz, 50MHz and 70MHz approx are now Ham bands. I've not noticed any significant noise on 50MHz SSB with a roof top aerial
