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The SB-102 dial lamps are #1815 which is a 14 volt lamp. They are wired in parallel across the 12.6 volt filament line. The lamp used for regulation in the LMO power supply is also a #1815. The meter lamp is a #47 which is a 6.3 volt lamp and wired across the 6.3 volt portion of the filament line.<br><br>73,<br>Ron, WM8Z<br>PH: 269-468-7780<br> <br>RTO Electronics<br>601 E. 1st Street<br>
Calexico, CA 92231<br><br>http://www.rtoham.com <br><br><br><br><br><br><div><div id="SkyDrivePlaceholder"></div>> From: kgordon2006@frontier.com<br>> To: Heath@puck.nether.net<br>> Date: Mon, 14 Jan 2013 09:32:44 -0800<br>> Subject: Re: [Heath] Light bulbs for HW/SB transceivers<br>> <br>> On 13 Jan 2013 at 18:41, Glen Zook wrote:<br>> <br>> > They are not 12.6-volt bulbs. The pilot lamps are wired either in<br>> > series with each other or are wired in the series-parallel arrangement<br>> > with all of the tube heaters ("filaments"). The bulbs themselves are<br>> > just plain old #47 and are available all over the place. Radio Shack<br>> > has them (although slightly higher priced than the normal electronic<br>> > parts outlets).<br>> <br>> Another point should be made here: there is a Heathkit service bulletin which <br>> directly addresses the pilot lamp issue for the HW-101 or SB-100/101/102.<br>> <br>> Some kits were supplied with #44 pilot lamps, instead of #47 bulbs: the #44 <br>> lamps draw 250 mA each, and thus unbalance the series-parallel filament <br>> string.<br>> <br>> The #47 bulbs draw 150 mA each, which is correct.<br>> <br>> Always use #47 pilot lamps, and make sure your rig does not have #44 <br>> lamps in it instead.<br>> <br>> Ken W7EKB<br>> <br>> _______________________________________________<br>> Heath mailing list<br>> Heath@puck.nether.net<br>> https://puck.nether.net/mailman/listinfo/heath<br></div> </div></body>
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