"Telamon" schreef in bericht
...
In article ,
craigm wrote:

From
http://groups.google.com/group/rec.r...dfd16b3dca3750
b3?dmode =source

1.- The ext. antenna socket is "hot", i.e. powered through a 470 ohm
resistence + 100 uH coil. This means that it will deliver approx. 10
mA DC current to the external antenna circuit. The coil is to
prevent "polluting" the power circuit of the radio with radio
frequency signal. Evidently, the purpose of this arrangement is to
"inform" the accessory antenna when the radio is turned on. In case
of the Sony AN-LP1 it turns on the antenna without need to use the
antenna power switch. However, the 7600G will NOT power the antenna,
the 10 mA are not enough to power the amplifier circuit. The power
for the AN-LP1 comes from its own batteries. You can use this
feature with any active antenna by including a proper power-up
circuit - a nice feature if your active antenna is located far away
from the radio and you want it to turn on and off automatically when
you use your radio.

This does not sound right to me. A power detect circuit would only need
micro-amps not 10 ma. 10 ma is respectable power for a simple amplifier.



According to the schematic for the antenna, only 6.4 mA is drawn from the
batteries ( 3 volts) when turned on.


The 'live' antenna imput of this radio is useful for a very simple home-built active
antenna.

http://groups.google.com/group/rec.r...d/5bb2bb0dc933
e3c5/e363b5117ffea249?lnk=st&q=&rnum=1&hl=nl#e363b5117f fea249

--
Greetings from Groningen ^top^ of Holland

MRe