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Old June 3rd 07, 12:29 AM posted to rec.radio.shortwave
Telamon Telamon is offline
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First recorded activity by RadioBanter: Jul 2006
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Default Sony 7600GR External Antenna Jack, Needs to be settled, Can it be shorted out to the point that it destroys the radio.

In article . com,
junius wrote:

On Jun 1, 9:58 am, junius wrote:
On Jun 1, 1:45 am, "Adam" wrote:





If you use a random wire in the Sony 7600GR radio and accidently
short it, can it destory the radio and/or cause damage or is it
protected?


In the manual it says it has DC power but on at least two
websites, it supposely only has a "sense power" to turn antennas
off and on.


I called sony customer support and they claim the jack doesn't
have any DC power in it, that it is only reception. This was said
by two different agents, but when I emailed them, they keep
talking about the headphone jack for some reason.


Will someone please settle this for me, it's like some are saying
it can short and at the same time, some are saying it can't at
all. I just want to have this darn thing settled.


Thanks in advanced.


I guess this touches to the issue of Sony putting a DC voltage to
the antenna jacks to power the AN-LP series of antennas.

The antenna jack on the ICF-SW07 does incorporate a DC voltage to
power the supplied AN-LP2 antenna. The instruction manual
accordingly warns:

"Do not connect any other antennas other than the recommended
active antennas to the AM EXT ANT jack of the unit, as the jack
supplies DC voltage to power the recommended active antennas."

Neither the instruction manual to the ICF-SW7600G nor that for the
ICF- SW7600GR has any similar such disclaimer.

In hooking up the AN-LP1 antenna to the ICF-SW7600GR, I have found
that the radio does not power the antenna. The antenna requires its
own batteries (unlike the AN-LP2 which can be powered directly by
the 'SW07).- Hide quoted text -

- Show quoted text -


To Adam, Mr. Alessandrini and Mike:

Perhaps you might find the following interesting:

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.

--
Telamon
Ventura, California