CB Radio

[KO]

I am about to leave on a 4 day trip from Florida to Banff National Park and I have been getting RV ready for last 4 weeks. I used to full time in it but have been in brick house for last 2.5 years.

I have a CB in it, but it is dead as channels don't light up and weather channel no longer work.

Is it worth replacing with new CB? There are many who are saying CB is dead, but I found it worthwhile for weather and why traffic is stopped.
Just wondering if this group still uses CB.

[TNGW1500SE]

Bumpyroad wrote:

Bumpyroad wrote:

wnjj wrote:

Bumpyroad wrote:

Tom_M wrote:

wnjj wrote:

Bumpyroad wrote:
I just got from Amazon a USB male connector to a cigarette lighter female connector. $9.99. suspect it will only be 5 volts however?????????????
bumpy

It says it's 12V and can't imagine it not being so. There are devices that make 12V from 5V. It likely won't produce much current at 12V though.

If it's this one:
https://www.amazon.com/ARECORD-Cigarette-Lighter-Socket-Converter/dp/B01J67JIOQ/ref=sr_1_3?ie=UTF8&q...

Specs say "Output:12V 0.8A Max".

that is the one but I thought those USB outlets were 5 volt?
bumpy

USB is 5V but as I said above, there are devices (IC's) that convert 5V to 12V. The IC's I work with regularly have onboard circuitry that generate +8.5V and -8.5V from a 1.2V supply.

tried it with my sirius radio.. did not work. haven't checked voltage yet.
bumpy

checked the voltage it does put out 12 volts.
bumpy

You may have 12 volts but I'd bet the amps are limited. Key up the mic and see what happens to the voltage.

[Bumpyroad]

Bumpyroad wrote:

wnjj wrote:

Bumpyroad wrote:

Tom_M wrote:

wnjj wrote:

Bumpyroad wrote:
I just got from Amazon a USB male connector to a cigarette lighter female connector. $9.99. suspect it will only be 5 volts however?????????????
bumpy

It says it's 12V and can't imagine it not being so. There are devices that make 12V from 5V. It likely won't produce much current at 12V though.

If it's this one:
https://www.amazon.com/ARECORD-Cigarette-Lighter-Socket-Converter/dp/B01J67JIOQ/ref=sr_1_3?ie=UTF8&q...

Specs say "Output:12V 0.8A Max".

that is the one but I thought those USB outlets were 5 volt?
bumpy

USB is 5V but as I said above, there are devices (IC's) that convert 5V to 12V. The IC's I work with regularly have onboard circuitry that generate +8.5V and -8.5V from a 1.2V supply.

tried it with my sirius radio.. did not work. haven't checked voltage yet.
bumpy

checked the voltage it does put out 12 volts.
bumpy

[Bumpyroad]

wnjj wrote:

Bumpyroad wrote:

Tom_M wrote:

wnjj wrote:

Bumpyroad wrote:
I just got from Amazon a USB male connector to a cigarette lighter female connector. $9.99. suspect it will only be 5 volts however?????????????
bumpy

It says it's 12V and can't imagine it not being so. There are devices that make 12V from 5V. It likely won't produce much current at 12V though.

If it's this one:
https://www.amazon.com/ARECORD-Cigarette-Lighter-Socket-Converter/dp/B01J67JIOQ/ref=sr_1_3?ie=UTF8&q...

Specs say "Output:12V 0.8A Max".

that is the one but I thought those USB outlets were 5 volt?
bumpy

USB is 5V but as I said above, there are devices (IC's) that convert 5V to 12V. The IC's I work with regularly have onboard circuitry that generate +8.5V and -8.5V from a 1.2V supply.

tried it with my sirius radio.. did not work. haven't checked voltage yet.
bumpy

[wa8yxm]

Why was the change made from 5 to 4.. As someone pointed out they are nearly identically The measurement is taken at a different point.

In the old days when the power was 5 W in to the final many radios had tube type finals. And you measured the voltage and current going into the final and W-IE ((This is a DC circuit so that's the formula. Believe it or not that is NOT the formula for an AC circuit other than pure resistive).

Measuring RF-Power was much harder. Basically took a lab

Today RV power meters are common. Amplifers are solid state

If the final is 80% efficient (Which is fairly common among Tube and Solid state finals) 5 Watts in = 4 Watts out..

And in fact that is how they determined the "new" (4 watts out) method. they measured a 5 watt (in) Radio. or many.

The biggest difference is in the receivers. Now I will admit a well tuned Tube type receiver can be very impressive... I hope to buy one. and I can make them even more impressive (The one I hope to buy has that feature built in. but then it was my FIRST Short wave Radio Receiver)...

But modern Solid State receivers are very very well designed and it takes a lot to beat them in the senistivity department.

Plus better noise filtering

Means you can HEAR more.

And one rule I have with my 2-way Radios... If I can't hear 'em. no point trying to talk to 'em.

[Bumpyroad]

mike-s wrote:

They had roughly the same power, it's just measured differently.

did the old units have more power than the new ones?? if not, why was the change made from 5 to 4?
bumpy

[bucky]

KO wrote:
Go into a FlyingJ, Pilot or TA and look at the CB radio's for sale.

.

Beat me to it. They don't stock what doesn't sell.

[mike-s]

Bumpyroad wrote:

mike-s wrote:
Close. The old ones had a limit of 5 W input to the final amplifier. When they went to 40 channels, they changed that to 4 W output (AM).

that was when I thought I remembered also. so if you were in the market for a used CB, an old 23 channel would have 25% more power than a 40?

No. 5 W in doesn't make 5 W out. Amplifiers are not 100% efficient, which is why the final transistors are on heat sinks.
They had roughly the same power, it's just measured differently.

[Bumpyroad]

I checked Craig's list. a 200 watt and a 300 watt one there. 🙂
bumpy

[wa8yxm]

R3e 40 or however many ( Thought it was 23 but I'd have to research)

The limited channel radios will be older. NOW some older radios were great (AM or AM/FM car radios were very good in the old days. not so much today).

But for CB's.. In many if not most cases. The more modern Radio will be more sensitive on receive Better able to "Filter" out noise and better overall performance wise. due to advances in technology over the last 50 years.

[Bumpyroad]

mike-s wrote:
Close. The old ones had a limit of 5 W input to the final amplifier. When they went to 40 channels, they changed that to 4 W output (AM).

that was when I thought I remembered also. so if you were in the market for a used CB, an old 23 channel would have 25% more power than a 40?
bumpy

[mike-s]

TNGW1500SE wrote:
Older CB's were 23 channel. Then it was increased by FCC to 40 due to over-crowding. Same 4 watts either way unless illegally modified or modified and used by licensed HAM operator.

Close. The old ones had a limit of 5 W input to the final amplifier. When they went to 40 channels, they changed that to 4 W output (AM).

[TNGW1500SE]

Bumpyroad wrote:

TNGW1500SE wrote:
Craigslist. Search 40 channel cb radio.

actually would a 40 channel one be best? I thought that they went from 19 to 40 because of channel crowding, which is not currently an issue.
I "thought" that when the switch was made they lowered the power of the CB. My CBs haven't been "tuned" to any channel over 19 for ages, so I am wondering if wa8yxm would have a thought on this?
bumpy

Older CB's were 23 channel. Then it was increased by FCC to 40 due to over-crowding. Same 4 watts either way unless illegally modified or modified and used by licensed HAM operator. NOTE: Some walkie talkies legally transmitted up to 5 watts due to smaller antennas being installed. Many users added external amplifiers but that just "stepped all over" everyone else and caused issues for legal users. There just wasn't enough channels and power for the radios to be much use. It was a party line with to many people on the lines. To day with far less users, it could be a short range option.

CB antenna's are the most important factor. Antennas need tuned and should be tuned to the lowest SWR on channel 19 because that's in the middle of the band. It's a compromise on other channels.

If "power" is really of any importance, a stock CB is not the way to go anyway.

I'm no expert but I played with CB's as a kid.

Before buying a CB, listen to this: CB Stream


Today, if I wanted a emergency radio. I'd look at a Baofeng UV-5R. About 30 bucks on ebay. You really should get a ham license to use it to transmit but you can listen all day without a license. It's a dual band radio that broadcast on 145-155/400-480 MHz but be careful, it can broadcast on illegal frequencies that police and fire use.

If you really want to know what radio to buy, find a neighbor with 50 guns and a basement full of dried beans, he'll know.

[Bumpyroad]

TNGW1500SE wrote:
Craigslist. Search 40 channel cb radio.

actually would a 40 channel one be best? I thought that they went from 19 to 40 because of channel crowding, which is not currently an issue.
I "thought" that when the switch was made they lowered the power of the CB. My CBs haven't been "tuned" to any channel over 19 for ages, so I am wondering if wa8yxm would have a thought on this?
bumpy

[TNGW1500SE]

Craigslist. Search 40 channel cb radio.