Tuesday, September 15, 2020

Video: VHF Propagation Presentation by Jim Bacon, G3YLA

During the current COVID-19 pandemic, the Mid-Ulster Amateur Radio Club are continuing with their successful Tuesday night lecture series. Recently, they had an interesting talk on VHF Propagation from meteorologist Jim Bacon, G3YLA.


The video above can be broken down as follows...

00:00 to 07:00... Introduction

07:00 to 10:25... GB2RS VHF Propagation Report - A brief outline of how the weekly bulletin is put together for the RSGB news.

10:25 to 28:30... Tropospheric Propagation - In this section, Jim covers elevated and surface ducts as well as the best time to watch any high pressure weather systems.

28:30 to 1:12:30... Sporadic-E - This section covers meteors which are the fuel for Sporadic-E and the various trigger mechanisms like atmospheric gravity waves due to mountains, thunderstorms and changes in the Jet Stream.

1:12:30 to 1:13:50... Rainscatter - This mode of propagation at microwave frequencies is briefly covered.

1:13:50 to 1:21:20... Propquest - Sporadic-E prediction website

1:21:20 to 1:23:30... Pulling it all together - GB2RS VHF Propagation Report

1:23:30... Q&A

1 comment:

Des Walsh said...

Very interesting article . I was particularly interested in the description of tropospheric propagation ,having first experienced it decades ago whilst trying to receive BBC VHF radio when living in south Tipperary , mainly before all the RTE transposers went on air. With a very good aerial system I regularly had reception from S Wales and S W England.( even Welsh police NBFM in the 105 to 108 MHz area ).
At the moment ,mid-September , tropo reception is good but limited mainly to
BBC Radio 9 104.9 MHZ 20kW from Haverfordwest and at times 2.5kW Nation Radio 107.1 MHz from Preseli also Pembrokeshire. In fact BBC Radio 4 can be heard around Cork city on a car radio when the tropo is good. On a portable with just it's whip aerial signal level can be up to =44dBuV , ie about 150 uV .
This reception is spurring me on to go back on air on VHF and UHF ( as soon at the gardening is completed ! ). EI5CD 5km west of Cork Airport , ca 170m asl .