Форум радиолюбителей ДВ

форум Радиолюбительского ДВ портала => ДВ антенны => Тема начата: rn3aus от 18 Октябрь 2020, 16:26:09

Название: Приемные VLF антенны Paul Nicholson
Отправлено: rn3aus от 18 Октябрь 2020, 16:26:09

Многим из нас будет интересно посмотреть на приемную установку диапазона сверхдлинных волн, изготовленную Paul Nicholson.
В ответ на мою просьбу Paul любезно предоставил нам описание, фотографии и схемы.

Цитировать

Hi Alex,

 > yes indeed, this is the first reception of a VLF signal from
 > Russia in the UK so far!

Thanks, I updated the list

http://abelian.org/vlf/amateur-radio/

 > could you give us a short description of your receiving system,
 > it would be especially interesting to see the circuits of
 > low-noise amplifiers for electric and magnetic antennas.

Sure. Below, some links to the hardware for you to use.

E-field antenna: 2m x 4cm tube (water pipe) stuffed with wire
and acoustic ballast/damping. Base is about 2m above ground,
effective height 1.6m.

  http://abelian.org/vlf/tmp/170813a.jpg
(http://abelian.org/vlf/tmp/170813a.jpg)

E-field pre-amp AD823,

  http://abelian.org/vlf/prx-e1-1.pdf

which is located inside the base of the antenna tube.
(http://abelian.org/vlf/tmp/171129a.jpg)
  http://abelian.org/vlf/tmp/171129a.jpg
(http://abelian.org/vlf/tmp/171129b.jpg)
  http://abelian.org/vlf/tmp/171129b.jpg

A few metres away from the antenna is a box with a line driver
and power supply for the pre-amp.

Цитировать

http://abelian.org/vlf/tmp/171130a.jpg

  http://abelian.org/vlf/tmp/171130a.jpg

Pre-amp on the left, PSU/driver box on the right.
(http://abelian.org/vlf/tmp/171127a.jpg)
  http://abelian.org/vlf/tmp/171127a.jpg

A cat5 cable delivers 48V DC to power everything and a balanced
twisted pair downlinks the VLF signal. DC supply pair and VLF
pair are isolated at both ends of the cable so there is no
ground loop.

H-field antenna: Orthogonal rectangular loops 20m by 2m by 3 turns
(heavy duty mains cable), about 1 ohm and 370uH.
(http://abelian.org/vlf/p1010111r.jpg)
  http://abelian.org/vlf/p1010111r.jpg

(http://abelian.org/vlf/p1010102r.jpg)
  http://abelian.org/vlf/p1010102r.jpg

2-channel pre-amp, power conversion, and line driver all in one
big box.
(http://abelian.org/vlf/tmp/171216a.jpg)
  http://abelian.org/vlf/tmp/171216a.jpg

(The little box on the left is for amplitude calibration.)


Each channel has pre-amp circuit
  http://abelian.org/vlf/prx-h1-sim1.pdf

and the two line drivers are the same LT1010 circuit as used on
the E-field.

Again, cat5 with 48V DC on one pair and VLF signal on two other pairs.
All pairs isolated at both ends.

--
Paul Nicholson
--

Название: Re: Приемные VLF антенны Paul Nicholson
Отправлено: rw3adb от 20 Октябрь 2020, 16:36:20

Спасибо, Саш!
Очень интерестно и полезно!