It is possible to buy LEDs with light diffusers that can fit behind LCD displays.? It's kind of hit-or-miss with the sizes though. Adafruit has a few different ones.
Like this:?
They are thicker than an EL panel and there isn't always room.? If you have the space, doing it with LEDs is definitely the way to go.
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On 11/30/2024 9:31 PM, Peter E via groups.io wrote:
It may be possible but it makes it a pretty complex alternative to some simple LED's installed in place of the bulbs.
What would be really nice would be to remove the silver backing on the existing LCD's and replace that with EL panels?
Maybe a project for someone more adventurous than me....
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*From:* [email protected] <[email protected]> on behalf of Peter Gottlieb via groups.io <hpnpilot@...>
*Sent:* Sunday, 1 December 2024 1:28 PM
*To:* [email protected] <[email protected]>
*Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
EL backlighting is used in plenty of sensitive transceivers. Examples include
the Harris RF-350K and Tadiran PRC-2200.
On 11/30/2024 9:25 PM, Peter E via groups.io wrote:
Probably not, but I would think even 400Hz at high voltage would generate a
fair few harmonics right inside a sensitive receiver.
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*From:* [email protected] <[email protected]> on behalf of Peter
Gottlieb via groups.io <hpnpilot@...>
*Sent:* Sunday, 1 December 2024 1:19 PM
*To:* [email protected] <[email protected]>
*Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
Are the "string" wires different from regular electroluminscent panels?? Those
run at about 120 VAC 400 Hz which is pretty easy to create without much EMI.
On 11/30/2024 9:15 PM, Peter E via groups.io wrote:
Hi Dan,
I just looked up some info on electroluminescent wire. It needs to be driven
with high frequency AC at a fairly high voltage. Not something you would want
anywhere near a sensitive receiver I would think.
Cheers,
Peter
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*From:* [email protected] <[email protected]> on behalf of Dan Rae via
groups.io <danrae@...>
*Sent:* Sunday, 1 December 2024 9:37 AM
*To:* [email protected] <[email protected]>
*Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
On 11/30/2024 1:27 PM, Peter E via groups.io wrote:
Hi Dan,
Absolutely correct - I actually meant to say NiMh (must be getting old).
And of course I did mean /less/ prone to leakage :^) Even older.
I like your led lighting solution. I also wonder if it is possible to use
that electroluminescent "string" that is available in various places? That
would give really even illumination
Two things there, first there is not a lot of height between the existing
board and the front panel, so not a lot of room for those strips.? Secondly
you need the small surface mount LEDs that shine sideways to light the LCDs.
The original LED lighting on the GM needed a re-worked acrylic piece to
accommodate the only LEDs that were available at the time.
I've done a few like that, the only advice I'd give would be to buy some extra
LEDs, since they have a habit of jumping off the board never to be seen again.
73 - Dan
