talkback glitch

[Chatter]

i made a dumb ass move. i couldnt find a 50 ohm 1 watt resistor so i soldered two 47 ohm 1/2watts in parallel thinking that it would keep the same value only increasing the heat disapation. so, later i find that on my meter, that decreased the resistance by half and it was loud coming out of the speaker.
i just found a 100 ohm 1 watt laying around w/5% tol (meter reads 99.7). just a quick solder job and back in business untill i put the meter on it to make sure every thing was good, now the 100 ohm resistor reads 11.2!
WHAT THE F*%@ is going on here?????

 

[wcsd106]

First question: Does the talkback work properly now?

If you attempt to measure the value of a resistor in circuit, you're going to get a false reading. If you lift 1 leg of that resistor, then measure across it, you should still see ~100ohms.

 

[Chatter]

it does work, its alot quieter now but it does work.

 

[wcsd106]

Changing the value of that resistor is how you adjust your talkback volume.

I've always started with a 100 ohm for a baseline.. if it's too low, you can go down towards 47 ohms.. too loud and you can move up to around 220 ohms... All depends on what you're looking for..

Personally, if I have talkback in a radio I always make it switchable.. I use it to adjust echo or whatever and then shut it off.

 

[Chatter]

i do like it loud, the 47 ohm that i have is only 1/2 a watt. is that o.k.???

 

[wcsd106]

Should be.. I usually use 1/2 watt resistors for talkback.

 

[Chatter]

cool, thanks alot for the help

 

[mackmobile43]

I would think you could even use a 1/8 watt resistor in that circuit, there is little to no current so heat is not an issue.