[ICOM] 7800

[Adam Farson]

Hi Marc,

You can measure (S+N)/N with an AC voltmeter (a VU-meter or a DMM). 10 dB =
3.16 as a voltage ratio. No ears needed.

Connect the meter across the speaker output, set the AF gain control for 50
mV on noise alone, and increase the RF signal power until the indicated
voltage is 160 mV. This is the receiver sensitivity for 10 dB (S+N)/N.

Cheers for now, 73,
Adam VA7OJ/AB4OJ


-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of mecker at peoplepc.com
Sent: 2-Jul-08 22:34
To: ICOM Reflector
Subject: Re: [ICOM] 7800

Have one. Trying to find out what to expect overall from this models
S-meter. Since I have a hearing loss, its not easy for me to test (s+n/n)
Wondering if this S meter (being digital and all) tends to be conservative.
Rigs like my ft-847 greatly exaggerate s reports.
-Marc.