Cobra 29 LTD Classic R56 and lost ferrite bead

[hacksaw1340]

HI,

L28, bead, where can I find or buy one? Do I need it? I'm thinking yea since its right next to a c1969. but I am still learning!



Thanks!!

 

[BC Coyote]

I keep a box of old defunct radio circuit boards under my bench for moments just like this.........
'cause it's a hassle to buy just one ferrite bead. Usually you have to order a minimum amount, you then use one and lose or misplace the rest before you ever need one again.

 

[guitar_199]

And, if I am understanding what I have read before about biasing of the RF final, you DO need it there. I am thinking that it serves as an RF choke to keep RF from splitting down into R56. The addition of the choke makes it a higher impedance path to the RF that is "just passin' through" to the final.

 

[nomadradio]

A tiny 1uH or 2uH rf choke will do the same job, in series with the resistor. The ferrite bead just makes the wire passing through it into an inductor. Slightly cheaper, especially when you're buying 10,000 of them at a time to feed your assembly line. A wirewound choke from a junk CB in series with that resistor will do the same thing.

73

 

[hacksaw1340]

A tiny 1uH or 2uH rf choke will do the same job, in series with the resistor. The ferrite bead just makes the wire passing through it into an inductor. Slightly cheaper, especially when you're buying 10,000 of them at a time to feed your assembly line. A wirewound choke from a junk CB in series with that resistor will do the same thing.

73

Great to know! I'll look for those. I have one junk radio. I think I know I need more. I buy those non-working radios and there's really nothing much wrong lol

Thanks everyone!

 

[Cable Guy]

I buy those non-working radios and there's really nothing much wrong lol

Careful there, that's how I ended up with stacks of working radios in every corner, crack and crevice, and 1 donor missing everything worth anything. The temptation to turn a working radio into an organ donor is ever present, that does seem silly to me, most of the time...

 

[hacksaw1340]

Careful there, that's how I ended up with stacks of working radios in every corner, crack and crevice, and 1 donor missing everything worth anything. The temptation to turn a working radio into an organ donor is ever present, that does seem silly to me, most of the time...

AHAHA oh crap. yes, I resemble that remark! I am up to 10 radios now and they all work. granted they're cobra 29 as I thought that would be a great place to start.

Oh man, the nicely working radio and using it for test parts is tough and very tempting. I have a good stock of diodes and caps, these little parts get me lost fast.

haha P.S. I got another 29 today, Now to find out why the LED segments that are out come back on. tapping and shaking made no difference. this might be fun. lol. or weird!


CB onward!!

 

[Cable Guy]

Yeah, you could also "borrow" a part, with all intentions of putting it back either with itself, or one stuck in transit, once it arrives. But please, if you do, make a note and put it inside the donor radio specifying what was borrowed, it's value and where it belongs. I got into the habit after, well, you get the idea lol.