LED pilot lamp substitute

[k4kyv]

These right-angle LED bulbs fit the standard S6 screw base.  Should make nice replacements to go in certain broadcast transmitters.

The price is a  little steep @ $18.95 each, but that wouldn't be too ridiculous since one would need only a couple of bulbs and they should last practically for ever.  The bitch clause is that they sell only in minimum quantities of 10.

The concept is a good idea. I think I can easily make my own using the bases removed from a couple of crapped out night-light bulbs, and some bright white LED's wired in series plus a dropping  resistor.

The DC voltage running the ones in my modified BC1-T craps out incandescent bulbs in no time.

http://www.ledtronics.com/products/ProductsDetails.aspx?WP=C450K708

[K6IC]

Hi Don,

A few years ago,  I floated this company's LED replacemant bayonet bulbs ...  have not tried them,  but some of them are about a buck.

The link to the top page is : (EDIT)  http://www.superbrightleds.com/led_prods.htm

Here is a link to their checkout page with some examples:

 http://www.superbrightleds.com/cgi-bin/store/commerce.cgi?product=CAR&next=50#LPC-W2

 Scroll down the page ... the BA9-x-12V is $0.98,  and avail in some colors.  There are others there,  BUT have not tried any of them.  Just FYI.   73  Vic

[Ed/KB1HYS]

Neat products.  Too bad about that min buy, 180 bucks for 10 small light bulbs seems a bit much.

I wonder if they generate any kind of RF noise?   

[k4kyv]

I wouldn't think they would generate rfi, since they are just led's with a current limiting  resistor.  I would assume they would work on both AC and DC, since they would self-rectify on AC.

[K6IC]

I would be very surprised if any of the small bayonet bulbs would generate any RFI issues.  Just a current source of some kind,  in the very inexpensive LEDs,  got to be just a resistor.

The SuperBright site usually specifies AC, DC or AC/DC,  But not in every case.

Generally,  one needs to use the LED in the manner it was intended to be used, ie, running a DC bulb on AC may damage it,  as LEDs are generally very sensitive to excessive reverse V.   Again in the more expensive bubls,  where there is a real current source device (not a resistor),  this reverse V can be handled.  A simple clamp diode could accommodate the reverse V,  but in t $1.00 bulb,  it is probably not there.  Using another LED as the reverse clamp is prob also absent in the dollar bulbs.

I kinna derailed this thread,  Don,  but have always marveled at the variety offered at the SBLED site ...  Guess that I should step up and get a few and report back.

73  C U on the bands.      Vic

[WA1GFZ]

A series connected LED, resistor and diode could be soldered right across the lamp socket or dead base and done for life. 

[k4kyv]

I converted the control circuitry in my Gates to DC, and this control voltage is used to illuminate the lamps, so an additional diode, rectification and reverse voltage would be a non-issue for me.

[WBear2GCR]

I think that most of these LED pilot lights with multiple LED chips use an LED driver chip, otherwise the output of the light would vary considerably with voltage supplied, and it would be difficult to drive multiple LED chips...

                              _-_-bear

[Opcom]

If it were AC, a capacitor could be put in series to set the current instead of a resistor. My TX has 120V pilot lamps. But why not just add a resistor behind the socket to cut the voltage a little so the lamps don't burn out? Cheaper than those overpriced LEDs.

[WA1GFZ]

each led has a forward voltage around 1.2 volts you can series them you have 6 or 12 volts than just use a current limiting resistor (no brainer)

[k4kyv]

I picked up a box full of bright white LED's just for  the purpose at Dayton last spring, but I haven't tried using them in the Gates yet.

I have had a problem with  LED flashlights.  In the past several years I purchased three different ones from widely different sources, and each time, before I wore out the second or even first set of batteries, the LED's began to fail.  First one would go dark, then another, until only one or two would still light up.  I gave up on them and returned to my old incandescent bulb Mag-Light that eats up batteries like madness.  Those LED flashlights remind me of "long life" CFL's.

I'll see if my homebrew lamp substitute lasts longer in the Gates than an  incandescent.

The stock Gates indicator lights are 220v versions.  I  run mine on 110v dc.  220v lamps are  difficult to find, but they might last longer on DC than 110v ones.  I forget the name of the phenomenon, but incandescent filaments deteriorate rapidly when run off DC.  For some reason related to the laws of physics, the surface of the filament wire erodes away until nothing is left.

In my 75A-4 I use 12-14v lamp equivalents to the stock pilot lamps, and some of them have lasted for over a decade of daily use.  Plus they give off a warmer, less harsh, amber glow that I much prefer over the stock 6-8v lamps that last a couple of months at most.

[K6IC]

Hey Don,

Many of the inexpensive LED flashlights  have NO current-limiting resistor.  THey rely on the internal Z of the batts -- these are the real cheapies.  These were often on keyring lights with Lion coin cells.

Dunno about ones with AAA etc,  but for me,  most of the very inexpensive FLs that use multiple cells are worth avoiding. There may be a quality problem with the LEDs themselves in cheap fls as well.  No corner left uncut kinna thing.

For me,  the best small FLs use a single 1.5 VDC battery and in inverter (step-up) to run the LED.  These run a long time,  have current limiting,  and will eagerly run on rechargeable NiMH batts  etc.  There are some 1-5 Watt FLs that use multi cells which are quality units

BUT,  Don,  I am not saying that you are buying el-cheapo Fls.   The Dorcey (sp ??) single AAA Fls go for years and years of daily use,  and years.  THe CMG 'infinity' FLs have run for me for 6 years or so,  and  they work great,  but  cost abut $18.00  (that many years ago),  but has a 100k hour bulb life. These two lights are great for finding ones way in the dark,  to the house from the remote shace,  finding stuff in the dark etc,  buy they are NOT intruder challenge lights.  Most of the law enforcement officers seem to be using LED rechargeable FLs  for their  'challenge work' and so on ...

am done  73  Vic

[WA1GFZ]

the LEDS in my homebrew frequency counter go back to 1975 and work fine current limited to 10 ma.

[k3sqp]

I'm using #47 led replacements from superbrightled.com . I couldn't decide what color to use
so my NC300 and NC303 have in the main dial from left to right, green-blue-red leds. Quite festive
and now I'm ready for the holidays...
Frank
K3SQP

[K6IC]

Hi Frank,

Thanks for the info.  You are the only person I know who has used these lamps from superbright.   Are you happy with them ?  Any additional comments ?

It does sound festive !           73  Vic

[k3sqp]

Hi Vic,

No issues atall. The white ones do tend to give that harsh "led" look...The amber ones seem to have the
look of incandescent, that warm look. I tried them because I was getting tired of replacing #47s.
Especially in the DX 100 with a solid case.Just to replace a lamp was a major disassembly. Besides
they do look kewelll..
Frank
K3SQP
( they are the elongated bulb like a #47  and may not phsically fit in applications using a round bulb like
a #50,, as in a Valiant/Ranger)

[Opcom]

looks good, and may run cooler. Many old dials were burnt by lamps over the years.

[Rob K2CU]

I have not be too happy with the so called white LED's. They are actually UV LED's with a fluorescent phosphor slapped on the die. Recently, Sylvania has come out with "warm white" LED light strings for Christmas. I looked at them at Home Depot where they have a test display to fire a few up. I swear they looked like incandescent lamps and had to take a second look to convince myself that they were LED's. I picked up a string for a source of warm white LED's for dial light subs. Remember to use a rectifying diode as well as current limiting resistor in AC applications. for starters, keep the average current to about 20 mA DC as measured with a VOM.

just a note that changing out the lamps in my TR7 to blue Led's reduced the warm up drift from 1500 Hz to 200Hz.

[kg8lb]

http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=/BA9S6_specs.htm

Among many other types, they have direct replacements for #47 types in AC applications. Many colors too.

 The blue LEDS look great in Drake gear and cost a lot less than the "dealer-dealer" stuff on Ebay from time to time..

  The frosted #47 style have good angle of coverage, matching the hot bulb coverage angle. Eliminates the filament image often seen when using hot bulbs to backlight dial scales. It took a while but I actually have come to like the white light . Makes the dials a lot easier to read with the 60 year old eyeballs. (IMHO)

  I use the green LEDs in DX-100 meter lighting. A nice match for the VFO dial's green.

  

[K6IC]

Thanks for the feedback,  Frank,  Rob & Gary.

I should give some of these a shot.  74  Thanks again,     Vic

[Opcom]

I have not be too happy with the so called white LED's. They are actually UV LED's with a fluorescent phosphor slapped on the die. Recently, Sylvania has come out with "warm white" LED light strings for Christmas. I looked at them at Home Depot where they have a test display to fire a few up. I swear they looked like incandescent lamps and had to take a second look to convince myself that they were LED's. I picked up a string for a source of warm white LED's for dial light subs. Remember to use a rectifying diode as well as current limiting resistor in AC applications. for starters, keep the average current to about 20 mA DC as measured with a VOM.

just a note that changing out the lamps in my TR7 to blue Led's reduced the warm up drift from 1500 Hz to 200Hz.

good comment on the white led. Some now have, besides the blue/UV die and the phosphor, another die or two that helps fill the spectrum. A cheap spectrometer will show you the colors from them.. A good white one, made for color accuracy rather than cheap flashlights, will have several bands each of a different color. Edmund has very cheap ones, made of the plastic tube and a diffraction grating on one end and a slit on the other. $2.. I have some that I have given to friends from time to time. I also boughttheir $40 one and am very happy with it. It has a calibrated scale. Looking at CFLs, TV sets, LEDs, and the like reveals much.