[Icom] Audio Muting

Mon, 25 Mar 2002 12:56:57 +0200

From what I found out with my TS140S, it appears that there is a =
resistor in
series with the headphone so that the audio level stays at some =
reasonable
level to prevent deafening signals in the 'phones. It is usually around =
47
ohms. Sooo, if you terminate the pug with something on the order of 47 =
to
100 ohms, it should be okay.
	In any case, since the audio output comes from a linear, class A or
B amplifier, the amplitude won't change too much even if you leave it =
open.
Alex Eban  4Z5KS
RF Chief Engineer
Wireless Division
M.T.I. Computers
Tel: +972 3 9025555ext321
Fax: +972 3 9025051
Email: [email protected] <[email protected]>=20

	-----Original Message-----
	From:	Rick Robinson [SMTP:[email protected]]
	Sent:	=E1 25 =EE=F8=F5 2002 3:27
	To:	Icom
	Subject:	[Icom] Audio Muting

	There are times when I want to use my headset(HS706) with my 746 and
my
	706MKIIG with all other audio muted except in the headset. If I put
a
	plug in the headphone jack of either radio this takes care of what I
	want to do but leaves me with the question of the open condition of
the
	headphone line. Something tells me that I should terminate a plug
with
	the resistance of the headphone output. The service manual on the
706
	lists the headphone imp. as 8 ohm and I cannot find the headphone
imp.
	of the 746 but the speaker is 8 ohm. If I do need to terminate the
plug
	what type of resistor do I use? Any other suggestions and comments
would
	be greatly appreciated. Tks, Rick
	----
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