I use incandescents with a CURRENT regulator. That makes for no inrush current
(5X running current) that kills the filament prematurely. A cheap and easy to
implement LM317L can be configured using ONE resistor to set the current. Every
5% less than the lamp's normal current results in a 50% increase in lamp life.
5% less current won't be noticed in lamp brightness. All the info is in the
LM317 datasheet. The only caveat is, the supply voltage needs to be at least
1.25V greater than the normal lamp voltage. Cost is about a buck each for the
LM317LZ (rated 100mA).
I treated my olde Kenwood TS120S and TS130S rigs ten years ago, and have yet to
experience another burned out lamp (the '130 is used mobile). The best thing
is, there's no ugly spotlight effect that is typical of LEDs (especially when
you don't use wide dispersion LEDs, or remove the LED's lens).
Date: Sat, 9 Aug 2014 11:26:13 -0500
>From: Gary <email@example.com>
>To: "firstname.lastname@example.org" <email@example.com>
>Subject: Re: [TowerTalk] LED fix for your rotator
>Nifty, I have run LEDs for several years. My experience has been very good as
>You can see my story here:
>> Date: Fri, 8 Aug 2014 20:28:01 -0700
>> From: firstname.lastname@example.org
>> To: email@example.com
>> Subject: [TowerTalk] LED fix for your rotator
>> The older I get, the harder it is to read the dial on my CDE/Hy-Gain/MFJ
>> control boxes. I never could get very good mileage on the 28 volt bulbs
>> by the internal meter power supply. Those bulbs were not regular residents
>> in my
>> junk box, and several attempts to provide illumination some other way were
>> than successes. I even tried the RotorEZ folks but they won't respond to
>> customers' calls.
>> Recently, I discovered an easy to provide, inexpensive, and easily
>> way to light up those control boxes. I just uploaded the article to my
>> Go to the home page on my website at: <www.hayseed.net\~jpk5lad\>
>> On the lower left area of the home page menu, choose "Repairing Antenna
>> This will take you to the "Repairing a Rotator" page that gives a selection
>> several articles on rebuilding and repairing ham antenna rotators.
>> The new article is titled, "Adding LED Illumination to Antenna Rotator
>> Box" and is menu choice #4.
>> I hope this provides you with some useful hints to make your ham activities
>> more enjoyable.
>> Jim - K5LAD
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