Is this resistor toast?

[mikay786]

Is the below resistor toast? I had my brother in law look at cb radio as he's into them and he says it is just a dummy resistor and its normal.

But looking at it, it looks badly charred, don't want to mess with it if its ok and looks a pain to remove board and the radio works fine.

[stj]

Re: Is this resistor toast?

that's done.
what make / model radio is it?

[mikay786]

Re: Is this resistor toast?

found a pic of resistor

blue grey gold gold

can I measure it in circuit board?

[mikay786]

Re: Is this resistor toast?

Yaesu FT-290R MK2

[SteveNielsen]

Re: Is this resistor toast?

I've seen toasted resistors like that still be within tolerance and keep working but it raises the question of why did it overheat like that in the first place. Look for THAT problem. It needs to be replaced regardless but it is not a dummy load resistor, it's only a 1/2 watt.

[mikay786]

Re: Is this resistor toast?

Is it possible to measure inline?

[goontron]

Re: Is this resistor toast?

I've seen toasted resistors like that still be within tolerance and keep working but it raises the question of why did it overheat like that in the first place. Look for THAT problem. It needs to be replaced regardless but it is not a dummy load resistor, it's only a 1/2 watt.

dummy load on a CB, the antenna did not have a proper loading coil would be my guess.

[stj]

Re: Is this resistor toast?

6.8ohm 5% probably about 1w and it should be non-inductive.

[stj]

Re: Is this resistor toast?

top-left on the 3rd schem.
6.8ohm .5w

[mikay786]

Re: Is this resistor toast?

Thanks STJ, I'm probably just going to leave it as the unit is functioning perfectly. My brother in law used for about a week with no issues.

Its a bit outside my comfort zone, replacing it isn't an issue but taking the unit apart and putting it back together.

[goontron]

Re: Is this resistor toast?

Thanks STJ, I'm probably just going to leave it as the unit is functioning perfectly. My brother in law used for about a week with no issues.

Its a bit outside my comfort zone, replacing it isn't an issue but taking the unit apart and putting it back together.

what frequency is the CB band in the UK? Same as the US (11m)?

[mikay786]

Re: Is this resistor toast?

what frequency is the CB band in the UK? Same as the US (11m)?

2m

[stj]

Re: Is this resistor toast?

depends if you mean the legal one!

there are actually about 4.
and they arent 2m - that's a HAM band.

[stj]

Re: Is this resistor toast?

http://ukspec.tripod.com/rf/handheld.html

one thing you wont see mentioned,
a lot of people in Europe are (mis)using the PMR band using modified radio's or ham radio's to transmit 16 channels of 5w power on the 8 channel 500mw band!

[SteveNielsen]

Re: Is this resistor toast?

It's on the 4th schematic, not the 3rd, and it is not a dummy load resistor. It is inline with +13.8v supply. Something shorted. Possibly a cap downstream connected to chassis gnd shorted then opened internally, like c34. The radio would probably still work without c34 but probably noisier audio and/or less stable than with it since that's audio output section.

[mikay786]

Re: Is this resistor toast?

It's on the 4th schematic, not the 3rd, and it is not a dummy load resistor. It is inline with +13.8v supply. Something shorted. Possibly a cap downstream connected to chassis gnd shorted then opened internally, like c34. The radio would probably still work without c34 but probably noisier audio and/or less stable than with it since that's audio output section.

I know it should be changed but my brother in law told me to leave it alone. If it ain't broke, don't fix it he says. Anyhow will see, just working on that Sony HiFi at moment.

[rhomanski]

Re: Is this resistor toast?

Is my toast resistive?

[goontron]

Re: Is this resistor toast?

Is my toast resistive?

i don't know about yours, but mine is. I like a nice layer of carbon on the outside

[stj]

Re: Is this resistor toast?

if you burn it enough it will be!

[rhomanski]

Re: Is this resistor toast?

Will the butter make it short?