| Author |
Message |
    
The_bandit
Junior Member
Username: The_bandit
Post Number: 15
Registered: 8-2002
| | Posted on Monday, May 15, 2006 - 3:10 am: | 
|
Hello, thanks for reading this.
I have an RCI-2950 which I've owned for many years.. probably on the order of 10 or more. I've used it for both Ham and 11 meter and it's probably my favorite radio out of my whole collection. Recently, one of the lamps which illuminate the display went out.. the other one is still good, but since they are wired in series, if one goes out the other does also.
I decided to replace the lamps in my RCI tonight with some color changing LED's which I purchased. These were part of novelty inkpens I bought when the local dollar store went under.. paid $0.50/ea for pens with 4 color changing LED's in them.
Installation was a breeze and went more quickly than expected.. however when I put everything back together and hooked the speaker back to the radio I've found that I can now "Hear" when the led switches colors... If I run the dim very low the noise is not as pronounced, but it can still be heard.... The noise almost sounds like a police siren as the LED fades in and out of each color and shifts.
I would like to keep using the led's since it is awesome to have a Ranger which shifts displays from Blue to green to red to orange to purple, etc on its own, but there is no way to deal with the noise.
Would anyone have a suggestion for what I can do with this? I'm thinking about bypassing each lead to ground using a small disc capacitor, but I'm not sure if that will cure the problem or not.
Thanks for any help anyone can provide. I hope i can get this mod to "sound" as good as it looks  |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1600
Registered: 9-2004
| | Posted on Monday, May 15, 2006 - 11:31 pm: |
|
these are just guesses, but maybe using a shielded cable instead of just wire.
try grounding the shield and also try not having the shield connected to anything on either end.
you could get some small ferrite beads and wrap four or five turns of the wire around the bead.
again, those are only guesses,
matt |
Chad
Advanced Member
Username: Chad
Post Number: 817
Registered: 11-2004
| | Posted on Tuesday, May 16, 2006 - 9:00 am: |
|
Caps to ground on both the positive and negative too. There are little tiny switcher supplies in there and are pulsing very fast. The dimming of the lamp is just a shorter pulse as the other one comes in you are probebly hearing the beat frequency.
Chad |
The_bandit
Junior Member
Username: The_bandit
Post Number: 21
Registered: 8-2002
| | Posted on Tuesday, May 16, 2006 - 3:19 pm: |
|
What would you suggest for values, chad?
I was thinking .01uF disc ceramic caps from each lead to ground and perhaps across the leads |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 682
Registered: 11-2002
| | Posted on Wednesday, May 17, 2006 - 12:00 am: |
|
Every radio I've done that to, you can hear it like that. That is weird huh? |
Bullfrog13x4
Junior Member
Username: Bullfrog13x4
Post Number: 40
Registered: 3-2006
| | Posted on Wednesday, May 17, 2006 - 3:09 am: |
|
posibly a rectifer and filter cap also if you that current.
Bullfrog13x4 |
Chad
Advanced Member
Username: Chad
Post Number: 823
Registered: 11-2004
| | Posted on Wednesday, May 17, 2006 - 9:34 am: |
|
That would probably work, give it a shot you can't hurt anything. |
Tech291
Moderator
Username: Tech291
Post Number: 389
Registered: 11-2004
| | Posted on Wednesday, May 17, 2006 - 8:19 pm: |
|
the led's(color-changing)have a built-in i.c. that contains an astable multi-vibrator circuit that in turn drives an oscilator generating the rise-fall tones your hearing.disc capacitors of the right values as suggested above should clamp the rf being generated in the led's
TECH291
CEF#291
KC8ZPJ |
The_bandit
Junior Member
Username: The_bandit
Post Number: 29
Registered: 8-2002
| | Posted on Sunday, May 21, 2006 - 8:10 pm: |
|
Well I made a parts order from ************ last night... needed to restock some of the parts in my junk box anyway.. ordered 100 or so .01uF disc ceramic and 100 or so .1uF disc ceramic.. when they come in later this week I'm going to try and see if I can at least get the whine down to an acceptable level. |
