Message from moderator Bozo
Ad blocker detected: Our website is made possible by displaying online advertisements to our visitors. Disable your ad blocker to continue using our website.
Cobra 139 Repair Help
Just any other questions that you don't see a forum for? Go ahead and post here.
Post Reply
4 posts
• Page 1 of 1
- Wraith
- NEW DUCK
- Posts: 0
- Joined: May 24th, 2024, 7:13 pm
- Handle: None For Now
- Real Name: Anton
Cobra 139 Repair Help
Hello, i know that this post is quite old, but i recently got myself a cobra 139 and the transmit does not seem to work on it, the main 13.8V drops to approximately 0.3 if not less, i’ve been trying to fix it, but to no avail, should i also attempt to replace all capacitors? Or could the problem be hidden somewhere else?
Since the other topic was older, I have created a new topic since it is a new question. The other topic was based on a previous user inquiry on the forum.
- Bozo
- Owner
- Posts: 9414
- Joined: August 31st, 2004, 1:06 pm
- Handle: Bozo The Clown
- Real Name: James Wadsworth
- Antenna: Monkey Made MM9
- Radio: General Lee Radio
- Contact:
Re: Cobra 139 Repair Help
Welcome to the forum, @Wraith
The issue you're facing with your Cobra 139's transmit function sounds like a tricky one.
replacing capacitors could potentially fix the problem, it's also possible that there's another underlying issue causing the voltage drop.
Before jumping into capacitor replacement, have you checked the wiring and connections thoroughly? Sometimes, a loose or faulty connection can lead to voltage drops. It might be worth inspecting the wiring and ensuring everything is securely connected.
Keep us posted on your progress, and don't hesitate to reach out if you need further assistance!
The issue you're facing with your Cobra 139's transmit function sounds like a tricky one.
replacing capacitors could potentially fix the problem, it's also possible that there's another underlying issue causing the voltage drop.
Before jumping into capacitor replacement, have you checked the wiring and connections thoroughly? Sometimes, a loose or faulty connection can lead to voltage drops. It might be worth inspecting the wiring and ensuring everything is securely connected.
Keep us posted on your progress, and don't hesitate to reach out if you need further assistance!
- Wraith
- NEW DUCK
- Posts: 0
- Joined: May 24th, 2024, 7:13 pm
- Handle: None For Now
- Real Name: Anton
Re: Cobra 139 Repair Help
Ah, thanks a lot, Bozo, i am pretty sure that there’s no wiring problems as i have studied the station many times and didn’t notice much except for the PA switch packed full of olive oil (i did clean it out though).
I was suspecting that i might’ve blown up the final or uh… Output transistors? (Sorry for not being aware of proper names of those parts of the station, i’m still very new to this) but i have pulled them out, checked and they seem fine.
Been checking all components that would dump the voltage to the ground if shorted but it didn’t result to much except me questioning my life choices.
I was suspecting that i might’ve blown up the final or uh… Output transistors? (Sorry for not being aware of proper names of those parts of the station, i’m still very new to this) but i have pulled them out, checked and they seem fine.
Been checking all components that would dump the voltage to the ground if shorted but it didn’t result to much except me questioning my life choices.
- Wraith
- NEW DUCK
- Posts: 0
- Joined: May 24th, 2024, 7:13 pm
- Handle: None For Now
- Real Name: Anton
Re: Cobra 139 Repair Help
So, i got the 3.5 volts on after finding a dead zenner’s diode but now i noticed that the s/rf pwr meter does not budge when the station is in the receive mode which is… Weird because previously it did jump up when turning on the station.
I’m quite tired of this station and trying to fix it…
I’m quite tired of this station and trying to fix it…
Post Reply
4 posts
• Page 1 of 1
Jump to
- Welcome and Community
- Skip Shooter's Paradise
- ↳ General Discussions
- ↳ Watergates & Videogates
- ↳ Shooting Skip
- ↳ Hall Of Fame
- ↳ Journal
- Radio Help
- ↳ Intro To Radios 101
- ↳ General Questions
- ↳ Base Setups
- ↳ Mobile 🚗 / 🏠 Base Install Help
- ↳ Competition Rigs
- ↳ Amplifiers / Power Supplies
- ↳ Charging System
- ↳ Mobile Setups
- ↳ Antenna Help
- ↳ Microphone Info
- ↳ Radio Modifications
- ↳ Shortwave Radios / Scanners
- ↳ Sideband (SSB)
- ↳ Tube Radio Equipment
- ↳ Other Technical Questions
- ↳ Miscellaneous Radio
- Buy / Sell / Trade
- ↳ For Sale Area Rules
- ↳ For Sale Area
- ↳ eBay Shopping
- ↳ Amazon Shopping
- ↳ Trade Equipment
- ↳ Wanted Radio Equipment
- ↳ Positive Feedback
- Off Topic
- ↳ Miscellaneous Chat
- ↳ Computer Help
- ↳ Signature Test Area
- The White House
- ↳ Ask Marv
- Federal Communications Commision (FCC)
- ↳ F.C.C. Rules And Regulations
- Home
- All times are UTC-06:00
- Cookie-Settings
- Delete cookies
- About us
- Downloads
- Contact us
Maxthon style by Culprit. Updated for phpBB3.3 by Ian Bradley
Powered by phpBB® Forum Software © phpBB Limited
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.