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Old 21st Jul 2019, 11:43 pm   #12
Skywave
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Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 6,854
Default Re: Aerial for old valve sets.

During 1967 - 1969 I was living with my parents and at school: I was an avid SWL. The receiver was an Eddystone 888A; the 'listening room' was my bedroom on the first floor. My aerial was a 110 ft. 'longwire'; the downlead was about only 5 ft. to an elementary C-L-C AMU (called an 'ATU' in those days). The earth was a copper tube 15 ft. long into moist earth connected to the ATU & RX. by a stout, flexible wire. The ground beneath most of the aerial was in a wide and deep hollow, effectively increasing the aerial height above ground quite substantially. (Probably about 40 ft. or more at max.)

O.K., so perhaps the sunspot activity was high, but with that set-up I heard Radio Amateurs on the 3.5, 7, 14, 21 and 28 MHz bands from all over the world. One of my favourites was listening to strong USA signals on their 75 m. band - usually at about 1 a.m. in the morning!

The point I am trying to make is this: the length of the downlead was very short in comparison to the total physical length of the aerial. And the earth connection was important too, especially for 1.8 and 3.5 MHz reception. The 'ATU' was also essential. (I still own that 'ATU', but not the Eddy. 888A, which IMHO, was the best AmRad only receiver that Eddystone ever built.).

Al.
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