Tell me about CB Radios

[TerryD]

Put one multimeter lead to the center pin of your cable at the radio end and the other to the vehicle body or outer part of the connector. It should be open, infinite resistance. If you get a reading there you have an issue with the antenna, cable, or mount.

 

[Chief Brody]

This is bugging me a bit,,, your original post stated you bought a "new in box, unopened" cb radio, and it doesn't work...

What happens when you buy another "new in box, unopened" radio, and that one doesn't work either?

it's a nos 1976 Midland new in box....38 years old

 

[Chief Brody]

Put one multimeter lead to the center pin of your cable at the radio end and the other to the vehicle body or outer part of the connector. It should be open, infinite resistance. If you get a reading there you have an issue with the antenna, cable, or mount.

I put the meter directly on the radio antenna "port" (on back of radio) in the center coax hole and the black lead to the outside part of the connector and got 50 ohms resistance

 

[TerryD]

You need to read your cable and antenna. The radio should be ohms.

 

[Fordum]

NO, take the antenna wire off the radio, measure ohms from the pin in the center of the connector to the outside shell of the wire connector, and just to be sure, measure from the center pin to a grounded part of the truck.

Should be no readings there. Open circuit. Going from the outside of the connector, you should have a dead short to the truck body.

There is nothing on the radio that you can measure that way. Also never key the mic with the antenna cable unhooked.

 

[Chief Brody]

OK...let's see if I can splain this accurately.

Obligatory photos of radio first:

 

[Chief Brody]

 

[Chief Brody]

OK...

When I get the meter probes and put the red probe into the center of the antennae connector on the back of the radio and I put the black probe on the outer ring, I get about 48 ohms

 

[Chief Brody]

When I put the black probe on the body ground (or battery ground) and the red probe in the center of the antennae connector I get zero...nothing...

 

[TerryD]

We know you measured the radio, you need to measure the cable going to the antenna while not attached to the radio. Are you keying this thing up without an antenna hooked to it?

 

[Chief Brody]

We know you measured the radio, you need to measure the cable going to the antenna while not attached to the radio. Are you keying this thing up without an antenna hooked to it?

I havent installed the antnnae on the blazer yet...it is just laying in the floor

 

[Chief Brody]

Shouldn't I hear something...anything without the antennae attached?

 

[Chief Brody]

Antennae checks out good...+ and - are completely seperate and insulated from each other

 

[Chief Brody]

there appears to be trouble at the radio...there appears to be a fault between the center pin and the ground of the antennae connector

 

[The Griff]

One thing I feel should be mentioned, never, ever key a radio without an antenna, thats a good way to start frying internals.

 

[TerryD]

Not being mounted, I doubt you will get much from the antenna. It needs a vehicle body or some large metal surface to work. I don't think anything is wrong with your radio. You need a SWR/power meter and dummy load to check it out without a base antenna or vehicle mounted one.

 

[Chief Brody]

Not being mounted, I doubt you will get much from the antenna. It needs a vehicle body or some large metal surface to work. I don't think anything is wrong with your radio. You need a SWR/power meter and dummy load to check it out without a base antenna or vehicle mounted one.

I will mount it to the truck and see if I get anything

 

[Chief Brody]

I hooked it all up and tested everything and nothing...I'm going to buy a brand new Cobra Classic

 

[Fordum]

just for fun, now that you have the antenna hooked up, measure from the pin to the outside part of the cable. And, from the pin to ground.

NOT the radio!

Trust me, the measurement from the center hole to the outside of the connector at the radio is totally meaningless.

 

[Chief Brody]

just for fun, now that you have the antenna hooked up, measure from the pin to the outside part of the cable. And, from the pin to ground.

NOT the radio!

Trust me, the measurement from the center hole to the outside of the connector at the radio is totally meaningless.

essentially you are saying test the coax cable?

Let's say everything is hooked up now...you want me to remove the coax from the radio and test that end of the coax