An OFCOM report prepared by an old work colleague

See http://stakeholders.ofcom.org.uk/market-data-research/other/technology-research/2015-reports/assessment-effects-of-repeaters-mobile-networks/.  This report for OFCOM (dated Nov 2015) was prepared by PA Consulting. My old work colleague, Simon Tonks, was involved according to LinkedIn.

15kW HF PA - definitely not for a QRP man!

A friend sent me this link http://www.dc9dz.de/en/index.html which shows the design and construction of a 15kW HF PA circuit for the amateur bands based around the Eimac 4CX10000D valve. Although I have no real interest in very high power and I do not expect to hear this on the air (please no!), it is a rather elegant piece of radio engineering.

A 100W PA for VLF use

BK Electronics in the UK make a range of MOSFET PA units with built-in toroidal power supplies. They have a 100W unit for £53, which is very reasonable for a built and tested unit. I believe these units work to 137kHz with a small modification and they would be ideal for 8.97kHz VLF use. There are versions up to 1kW, but these are quite expensive.

See http://www.bkelec.com/Modules/Amplifiers.htm