?

73

?

On Wednesday, April 9, 2025, 12:09 pm, Pentagrid via groups.io <dayleedwards@...> wrote:

I totally agree. The lack of powerful SW? stations though has its upside, especially with the Wadley loop receiver designs that have severe shortcomings with dynamic range and internal noise issues. Many weaker stations could not previously be heard especially with adjacent power house transmitters.? Almost all European countries have low power SW transmitters to serve internal communications, either domestic or utility. The FRG7 actually receives a swath of frequencies in a one meg bandwidth, or window. The wanted station is selected from this mess of frequencies by what in effect is a seperate radio receiver, ie, the tuneable IF. The minimalistic first mixer must cope with all that? mishmash of signals and atmospheric noise coming in through that wide open window.

With the big transmitters gone, patient and careful tuning can receive many many of these low power internal broadcast stations, of which there are literally thousands serving isolated parts of the world.

With? three signal mixing stages, the FRG7 will never be a quiet receiver, an optimised aerial will help enormously here.

If the wanted signal can be made strong enough, the internal self generated noise can be overridden to a great extent.? I have had very good results using a small MLA 30 amplified loop to reduce local noise, but any additional gain should be reduced to a minimum. With any amplified aerial , reduce the gain on atmospheric noise to what it is without the amplified aerial attachment. This will increase dynamic range and further reduce noise in the radio.? Additional? amplifier gain will NOT increase performance, its only? the local noise cancelling that is needed.

Sadly, modern houses are full of RFI from all those SMP supplies that nowadays are in everything. Not much can be done other than switching off the main offenders. RFI used to be policed well, but now, noone is bothered, especially the manufacturer who can save a penny or two by leaving any noise suppression out.

There are many ways to improve the performance of the FRG7, but its an interesting challenge to go with what you got. There are very few stations that my Icom R8600 can receive that the old Yaesu cant, and I know which radio is more fun to use.