Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: radioshack power supply problem  (Read 487 times)
KC9GPJ
Member

Posts: 37




Ignore
« on: January 05, 2008, 06:38:38 PM »

I have the latest 13.8v 25 amp radioshack power supply. When I transmit cw at 100 watts, the radio will randomly turn on and off. The volt meter on the radio shows that the voltage drops from 14v to around 12.5 v. Is this power supply garbage(its to old to return)? Can I do any modifications to make it keep its voltage up around 13.8v?
Logged
N2IK
Member

Posts: 220




Ignore
« Reply #1 on: January 05, 2008, 07:52:43 PM »

Sounds like you have RF getting into the DC leads of the power supply and it is affecting the regulation.

Is the radio chassis bonded to the power supply chassis? I would try that and also try Ferrite chokes on the DC leads. Keep the transmission line away from the DC supply leads as much as you can may also help.

73 de Walt N2IK
Logged
W3LK
Member

Posts: 5644




Ignore
« Reply #2 on: January 06, 2008, 11:39:57 AM »

What are you using for an antenna?

73,

Lon - W3LK
Naugatuck, Connecticut
Logged

A smoking section in a restaurant makes as much sense as a peeing section in a swimming pool.
K4DPK
Member

Posts: 1077


WWW

Ignore
« Reply #3 on: January 06, 2008, 08:00:04 PM »

There may not be anything at all wrong with the power supply.  Use an outboard voltmeter and check the voltage at the PS.  Compare to the reading on the radio voltmeter.  If the outboard voltmeter agrees with the 12.5 v reading on the radio, the PS is losing regulation.  If the PS has 14 v and the radio shows 12.5, you most likely have a loose connection.

If the voltage drop is on the way to the radio, you can try pushing the power connector to one side while transmitting to see if it clears up.  Check all your connections.

73
Phil C. Sr.
k4dpk
Logged
KC9GPJ
Member

Posts: 37




Ignore
« Reply #4 on: January 07, 2008, 08:10:37 AM »

Thanks for the replies.
I have a G5RV only about 10 ft from the power supply and the ladder line goes right by the power supply's cables that go to the radio. That probably is my problem. Would winding the power supply's cables as much as possible make an rf choke?
Logged
W6TH
Member

Posts: 1




Ignore
« Reply #5 on: January 17, 2008, 08:09:46 AM »

.
Try running less power and check to see if the radio now operates correctly. If so, then remove that feed line away as much as possible as it sure looks like rf into your supply. Grounding power supply, etc., to radio also helps .
.:
Logged
W3LK
Member

Posts: 5644




Ignore
« Reply #6 on: January 17, 2008, 05:26:40 PM »

<< I have a G5RV only about 10 ft from the power supply and the ladder line goes right by the power supply's cables that go to the radio. That probably is my problem.>>

There's no "probably" about it; that is your problem.

Why is there ladder line next to the power supply? There's supposed to be a section of coax between the rig/tuner and the ladder line. How do you have the ladder line connected to the rig?

73,

Lon - W3LK
Naugatuck, Connecticut
Logged

A smoking section in a restaurant makes as much sense as a peeing section in a swimming pool.
W3LK
Member

Posts: 5644




Ignore
« Reply #7 on: January 17, 2008, 05:27:46 PM »

<< Would winding the power supply's cables as much as possible make an rf choke?>

No.

73,

Lon - W3LK
Naugatuck, Connecticut
Logged

A smoking section in a restaurant makes as much sense as a peeing section in a swimming pool.
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!