What do you think?

[troutscott]

Hi
I bought a used Uniden PC76xl cb off e-bay and received it yesterday.
The radio appears to be in great condition.
I hooked up a Radio Shack magnetic mount antenna and stuck it to a cookie sheet and set it on a book shelf.
I live in a apartment about 2 blocks from a major free-way so I thought I would definitely hear a bit of traffic.

Not only do I not hear anyone but when I key up the mike the transmit meter does not move.
I have checked all the settings on the radio to make sure that they are in the right position.
Is it the antenna ?
Is it my power supply? I am using an Ac adapter that outputs 12 v from 120 v at an amp rating of 2700ma.

Any help would be greatly appreciated,
Scott

P.S. The radio does have an Antenna light which does not light when mike is keyed

 

[mmckenna]

Hi
I bought a used Uniden PC76xl cb off e-bay and received it yesterday.
The radio appears to be in great condition.
I hooked up a Radio Shack magnetic mount antenna and stuck it to a cookie sheet and set it on a book shelf.
I live in a apartment about 2 blocks from a major free-way so I thought I would definitely hear a bit of traffic.

Not necessarily. Last year, I drove from California to Texas and back. On a whim, I picked up a CB and put it in my truck for the drive. Permanent mount antenna, tuned dang near perfectly, proper power, grounding, etc.
In a total of about 6 days of driving, I heard very little CB traffic. Very few truckers talking, I did hear one wife/husband talking that were moving cross country. A fair amount of traffic coming in via skip from all over the country, but not consistently.

So, the fact you are not hearing much isn't surprising.

Not only do I not hear anyone but when I key up the mike the transmit meter does not move.

That could indicate an issue. You really need an SWR meter to tell you if the radio is transmitting or not.

I have checked all the settings on the radio to make sure that they are in the right position.

Make sure the RF gain is set to "Max".

Is it the antenna ?

Could be. A cookie sheet doesn't provide anywhere near enough ground plane for 27MHz.
Using antennas indoors can be an issue. Depending on the construction of your apartment, it can cause issues. Metal lath behind plaster will block RF. Foil backed insulation can block RF. Metal siding can block RF. Even thick masonry can attenuate RF.
Add in that there could be a very high noise floor from computers, appliances, TV's, and not just yours, but your neighbors. Using CB antennas indoors usually results in very poor performance, but I understand the limitations you are up against. You may need to get creative with your antenna system.

Is it my power supply? I am using an Ac adapter that outputs 12 v from 120 v at an amp rating of 2700ma.

Could be. 2700ma = 2.7 amps. That might be a little low to power the CB while transmitting. Also, if it's an unregulated power supply, it could have voltage levels varying greatly. If it doesn't have good filtering, it can generate a lot of RF noise that will essentially deafen your radio.

You need a 12 volt regulated power supply, probably one that does at least 5 amps, with good filtering.

P.S. The radio does have an Antenna light which does not light when mike is keyed

The "ANT" light is supposed to light up when the SWR is too high. Normally it would be good it is not lit, but I wouldn't trust it.
You should read up on how to use the internal SWR meter to check power output and the tuning of your antenna. But I wouldn't expect the SWR to be low using a CB antenna indoors.

And then, there's the possibility that the radio could just be broken. Without having some basic test equipment or someone to try talking to, it'll be hard to narrow down.

You might want to try taking the radio and antenna outside and giving it a try.

 

[troutscott]

Great information
Thank you

 

[chief21]

One thought... If the radio has a CB / PA switch, be sure that the switch is in the CB position,