It's normal for power to deflect downward on AM during modulation. You have to have a peak reading wattmeter to see the peaks..... Sounds like you have good modulation. Cory/AD5QP
Tom Elmore <[EMAIL PROTECTED]> wrote: I am in the process of restoring a B&W 5100B transmitter and am using a Coaxial Dynamics wattmeter to measure power. I normally use this meter for CW & SSB and noticed that when monitoring an AM carrier the meter deflects downward with modulation. Is this a characteristic of this meter or maybe an issue with the transmitter itself. Thank You Thomas Elmore KA1NVZ Anchorage, Alaska ______________________________________________________________ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:[email protected] --------------------------------- Do you Yahoo!? vote.yahoo.com - Register online to vote today! From [EMAIL PROTECTED] Mon Oct 11 10:33:44 2004 Return-Path: <[EMAIL PROTECTED]> Delivered-To: [email protected] Received: from web81001.mail.yahoo.com (web81001.mail.yahoo.com [206.190.37.146]) by mailman.qth.net (Postfix) with SMTP id D4505859D1A for <[email protected]>; Mon, 11 Oct 2004 10:33:41 -0400 (EDT) Message-ID: <[EMAIL PROTECTED]> Received: from [12.14.128.194] by web81001.mail.yahoo.com via HTTP; Mon, 11 Oct 2004 07:24:39 PDT Date: Mon, 11 Oct 2004 07:24:39 -0700 (PDT) From: Jim Candela <[EMAIL PROTECTED]> Subject: Re: [AMRadio] B&W 5100B To: Discussion of AM Radio <[email protected]> In-Reply-To: <[EMAIL PROTECTED]> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-BeenThere: [email protected] X-Mailman-Version: 2.1.4 Precedence: list Reply-To: Discussion of AM Radio <[email protected]> List-Id: Discussion of AM Radio <amradio.mailman.qth.net> List-Unsubscribe: <http://mailman.qth.net/mailman/listinfo/amradio>, <mailto:[EMAIL PROTECTED]> List-Archive: <http://mailman.qth.net/mailman/private/amradio> List-Post: <mailto:[email protected]> List-Help: <mailto:[EMAIL PROTECTED]> List-Subscribe: <http://mailman.qth.net/mailman/listinfo/amradio>, <mailto:[EMAIL PROTECTED]> X-List-Received-Date: Mon, 11 Oct 2004 14:33:44 -0000 Cory, I once had a peak responding watt-meter, and you are correct they are necessary to see the peaks. With my ultra-modulated Viking I it read 100 watts carrier, and 400 watts PEP at 100% tone modulation. It also read 800 watts at 200% + modulation. If I switched to average mode it read 150 watts at 100% tone modulation. I currently use a Bird wattmeter without the peak option. It too shows a 50% rise in power at 100% tone modulation so long as my transmitter has no carrier shift. A RF amp meter if in line with the RF output should show a 22.5% rise at 100% tone modulation. Regards, Jim --- Cory Hine <[EMAIL PROTECTED]> wrote: > It's normal for power to deflect downward on AM > during modulation. You have to have a peak reading > wattmeter to see the peaks..... Sounds like you have > good modulation. > > Cory/AD5QP > > Tom Elmore <[EMAIL PROTECTED]> wrote: > I am in the process of restoring a B&W 5100B > transmitter and am using a > Coaxial Dynamics > wattmeter to measure power. I normally use this > meter for CW & SSB and > noticed that when monitoring an AM carrier the meter > deflects downward with > modulation. Is this a characteristic of this meter > or maybe an issue with > the transmitter itself. > > Thank You > Thomas Elmore KA1NVZ > Anchorage, Alaska > > ______________________________________________________________ > AMRadio mailing list > Home: > http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > > > --------------------------------- > Do you Yahoo!? > vote.yahoo.com - Register online to vote today! > ______________________________________________________________ > AMRadio mailing list > Home: > http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] >
