[Resolved] What Part did I just Break? 90s Tech

Other Hardware General Electronics
1

Hello Arduino Forum,

I am new here, so hopefully I am posting in the right section. Today I broke an rc circuit board from the 90s. There was a screw hole where this part was >:( . Any ideas as to what the part could be? It connected to four pins, including the antenna (yellow wire). It was a fragile clear piece which was wrapped in flimsy wire. It connected to four pins; any help would be greatly appreciated.

Picture of the part:

Picture of where it was on the board:

https://ibb.co/dNRiZ7

2

Picture of the part: 0415182009 hosted at ImgBB — ImgBB
Picture of where it was on the board: https://ibb.co/dNRiZ7

You broke a tuning coil.

How to post an image here:-
image guide

3

If you have 4 pins but only 2 of them are used - only one coil.
That is it antenna adjustable inductor as on picture except capacitor, on the drawing you can tune antenna using capacitor in you case that running is done by ferrite.core.

https://get.google.com/albumarchive/109923199728365379375/album/AF1QipPFJzblMQJsHkW3TOcWufJaQD5Qd6emKAegQMV7/AF1QipPo1yaM1fl-29zkPDNLh3F5CLtDlz1z85tpR_Ds?source=pwa#6191399810489818482

https://www.google.ca/search?rlz=1C1AFAB_enCA475&biw=1440&bih=787&tbm=isch&sa=1&ei=ufbTWpuWMMzTjgT2kruIBg&q=adjustable+inductor&oq=adjustable+inductor&gs_l=psy-ab.12..0j0i30k1.12238.19420.0.24718.10.10.0.0.0.0.136.836.9j1.10.0....0...1c.1.64.psy-ab..0.10.832...0i7i30k1j0i8i7i30k1j0i13k1.0.kpzUDflJS2A#imgdii=ojUsP-8LvLDcsM:&imgrc=kpwX_icFw79g2M:

4

Thanks guys! Hmm... I think this is just about the exact same part that broke, minus the 4 pins: https://www.ebay.com/itm/322498352436 So just solder the pins together and have the coil bridge the arc?

Curious question: would a resistor work in theory?

Thanks for the note on images as well! I tried adding them, but they do not show on my screen now.

5

I think this is just about the exact same part that broke

I doubt it. If you had a remote car then that coil would probably resonate at 27MHz that one probably doesn't. It is impossible to tell because it is the capacitor along with the coil's inductance that determine the resonance.

Curious question: would a resistor work in theory?

No

I tried adding them, but they do not show on my screen now.

Then you did not do it right. You can't use the URL from that site, because sites like that do not send the image in response to an embedded URL, because they are bastards and want the web hits for themselves.

6

It is not exact, you have to tune LC circuit to 27 MHz, so count the numbers of the turns in original part, resistor can not be used for resonance tuning.
You need this.

https://www.google.ca/search?rlz=1C1AFAB_enCA475&biw=1440&bih=787&tbm=isch&sa=1&ei=ufbTWpuWMMzTjgT2kruIBg&q=adjustable+inductor&oq=adjustable+inductor&gs_l=psy-ab.12..0j0i30k1.12238.19420.0.24718.10.10.0.0.0.0.136.836.9j1.10.0....0...1c.1.64.psy-ab..0.10.832...0i7i30k1j0i8i7i30k1j0i13k1.0.kpzUDflJS2A#imgrc=V-IfrD8iBaFzzM:

7

https://www.dhgate.com/product/10pcs-adjustable-inductor-0-09uh-0-20uh-90nh/406659017.html

8

Okay, makes sense. I'll use a different image host next time. That is annoying.

This is 25 - 100 mhz, but has an extra pin. Do I just not use one of the pins?

https://www.ebay.com/itm/10pcs-adjustable-high-frequency-ferrite-core-inductor-12T-0-6-1-7uh-New-Branded/252413461676?_trkparms=aid%3D444000%26algo%3DSOI.DEFAULT%26ao%3D1%26asc%3D50998%26meid%3Db2594475b3614f758a0f85f99d4aecab%26pid%3D100752%26rk%3D1%26rkt%3D6%26sd%3D252465839100%26itm%3D252413461676&_trksid=p2047675.c100752.m1982#shpCntId

For the one at DHgate, would only three pins work?

9

This is 25 - 100 mhz, but has an extra pin. Do I just not use one of the pins?

Look on the underside of the PCB to see if the traces to the four pins go to different places.

It is unlikely that the link you posted is a viable replacement as the number of turns are not the same.

10

drewtoby:
Okay, makes sense. I'll use a different image host next time. That is annoying.

This is 25 - 100 mhz, but has an extra pin. Do I just not use one of the pins?

Cut the pin in center and you are ok, Cut the pin in center and you are ok, maybe you need change the number of turns

11

Thank you all so much! I'll get both and play around with the setup. I will get the three-pin one as well to be safe (i found it on ebay from the same seller).

12

drewtoby:
I'll use a different image host next time. That is annoying.

It's possible to use images from that host. You just need to get the actual image URL:

618×640 91.1 KB

But better yet, if you read the guide at the link Grumpy_Mike posted, it shows how you can attach the image to your forum post and then embed that same image, so you don't need to use an external host. This is nice because it makes it less likely that the images will break over time, which often causes information on a forum to become less useful as a reference over time. Until you have reached your 100th post the forum does make you wait 30 seconds before you can edit your post to embed the images but that's not too long to wait.