John Plimmer wrote:
I have a Datong AD-270 = very noisy antenna.
My DX pals have ALA1530's and I would exchange the Datong for a Wellbrook
anyday.

--
John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XR 30, Braun T1000, Sangean 818 & 803A.
GE circa 50's radiogram
Antenna's RF Systems DX 1 Pro, Datong AD-270
Kiwa MW Loop
http://www.dxing.info/about/dxers/plimmer.dx

I mounted the AD370 on a tree and connected it to
the R2000 on the kitchen table. With the PS side
amplifier in the off position there is minimal noise.
Compared to "North Country" or the AMRAD it is very
close. With the never to be cursed enough MW station
on 770KHz and another local on 1240KHz I have some
very constant signals for IMD. The AMRAD is imune,
no mix products, the NC has some minor mix + and
a very weak 2nd and 3rd harmonic that is internal to
the antenna under test. The AD370 has a very slight,
as in right at the noise floor, mix + (770+1240) and
maybe a weak 3rd harmonic of 770 (2,310KHz). Hard
to be sure as it is right at the noise floor. I can only
find it with a FFT window.

With the additional amplifier the noise floor really jumps up.
A better amp would likely be the Lankford "ultra linear amp"
at http://www.kongsfjord.no/

At this point I have NO regrets about the trade.


Terry