Clueless

[Ensnared]

I am going to ask a question that I know will elicit all types of responses, so here goes.

Generally speaking, what types of modifications are made to CB radios. I am not talking about adding components to the radio either.

I know about "peaking" the radio, but I don't really know what that means.

The reason I am asking is I own several CB radios. One, I bought at the Joplin 44 Truck Stop in Missouri for $35.00. As I have stated, that was the best money I ever spent on a radio. It has been a champ.

I know that "talk back" was one of the modifications made, but is it possible to increase the RF gain?

My unmodified Cobra 25 does not receive as well. It is a huge difference.

So, when people talk about modifying a radio, without adding components, what does this entail?

 

[needairtime]

Peaking... seems to be tuning the radio for peak performance. It seems that all radios are dumped out without testing the actual capabilities of the radio - manufacturers target slightly under the limit to ensure they don't have any outliers that exceed legal limits. Peaking will individually tune that radio up to the legal limit. Part of the process of peaking include:

- tuning up to 4W (over 4W = FCC violation, 3.8W = not quite there maximum...)
- increasing modulation to 100% (over 100% modulation = distortion on transmit, 70% = you could be louder to other people)
- tuning to optimal receive gain (this is delicate as too much gain will amplify noise).

Usually these things can be done without changing components but you need to know the actual circuit and have test equipment to get them to their fullest potential.

As with all things inside a CB radio, you need to be licensed to legally work on CB radios to ensure you don't tune the radio to 4.2W just because the customer wants it.

 

[AK9R]

As with all things inside a CB radio, you need to be licensed to legally work on CB radios...

What license would that be?

Can you cite the FCC rule that stipulates that you must be licensed in order to work on CB radios?

 

[Tech792]

Technician licensing was dropped many years ago for most services (including CB and Land Mobile). But I believe is still required for avionics and marine services.

 

[needairtime]

Actually it's more of the ending up with a radio that's still within specs. Just need to meet FCC rules 95.221. They need to know enough about the circuit to ensure that any changes do not exceed limits.

No such requirement to use the radio of course, that has been like that for a long while now.

 

[KK4JUG]

Technician licensing was dropped many years ago for most services (including CB and Land Mobile). But I believe is still required for avionics and marine services.

Avionics and marine are licensed by rule.

 

[jaspence]

If you start making internal adjustments and don't know what you are doing, you can easily end up with a useless radio. Turning up the power may give you more output, but going to 10 watts from 5 does not double the output. It may, however, blow out the finals.

 

[AK9R]

Just need to meet FCC rules 95.221.

95.101 to 95.299 are reserved. There is no 95.221 in the current CFR.

Yes, I know that you don't need a license to use a CB radio. You stated "you need to be licensed to legally work on CB radios" and I would like to know which FCC rule that stipulates this.

 

[Frankhappyg]

Reminds me of my younger days when I was 13-14 years old and CB’s was the thing to do for us boys.
Had a Realistic Navaho with a D-104 and a Linear amp....oh the good old days.



Sent from my iPhone using Tapatalk

 

[ScannerMan1989]

I am going to ask a question that I know will elicit all types of responses, so here goes.

Generally speaking, what types of modifications are made to CB radios. I am not talking about adding components to the radio either.

I know about "peaking" the radio, but I don't really know what that means.

The reason I am asking is I own several CB radios. One, I bought at the Joplin 44 Truck Stop in Missouri for $35.00. As I have stated, that was the best money I ever spent on a radio. It has been a champ.

I know that "talk back" was one of the modifications made, but is it possible to increase the RF gain?

My unmodified Cobra 25 does not receive as well. It is a huge difference.

So, when people talk about modifying a radio, without adding components, what does this entail?

OMG no way man that's illegal im callin the fcc you can't you are forbidden!!!! Modden Verbotten







Just kidding. The answer lies in the resistors and a few diodes I think...
ATM I am trying to enhance my rig but no avail I think the CPU locked out... :roll:
NOTHING wrong with getting the most out of an investment as far as it will go

 

[jaspence]

"The answer lies in the resistors and a few diodes I think..." Scannerman quote

And we will just forget about the capacitors, tuning coils, transistors, ICs etc. and give it the old smoke test.

 

[KK4JUG]

A little puff of smoke and a slight whiff of ozone followed by the word, "Oops."

 

[ScannerMan1989]

"The answer lies in the resistors and a few diodes I think..." Scannerman quote

And we will just forget about the capacitors, tuning coils, transistors, ICs etc. and give it the old smoke test.

I meant those too

 

[nd5y]

https://www.fcc.gov/wireless/bureau...ion/commercial-radio-operator-license-program

You do NOT need a commercial radio operator license to operate, repair, or maintain any of the following types of stations:

• Two-way land mobile radio equipment, such as that used by police and fire departments, taxicabs and truckers, businesses and industries, ambulances and rescue squads, and local, state, and federal government agencies.
• Personal radio equipment used in the Citizens Band Radio Service (CBRS), Radio Control Radio Service (RCRS), and General Mobile Radio Services (GMRS).
• Auxiliary broadcast stations, such as remote pickup stations.
• Domestic public fixed and mobile radio systems, such as mobile telephone systems, cellular systems, rural radio systems, point-to-point microwave systems, multipoint distribution systems, etc.
• Stations that operate in the Cable Television Relay Service.
• Satellite stations, both uplink and downlink of all types.

 

[needairtime]

Then there's also the question of modification which includes tuning (versus repair...)
You're right there's no explicit rule for modification, other than the resultant system still needs to follow the rules, and I took it that pretty the original manufacturer of the radio that designed and did the testing to get the radio approved is the only one authorized to make changes as they know what it takes to keep the radio legal.

 

[FiveFilter]

I've never been in a radio shop myself since the only problem I have had with a radio was with a new one under warranty, and the factory sent me a new replacement.

However, I have read many times that people will ask a radio tech to increase the performance of their radio, as in, getting more communication range out of it and make it "louder ". Some techs, derisively called "Golden Screwdrivers" by some, are more than willing to modify the radio so that they can show you a higher wattage number on their instrument and tell you the extra power will get you more range, but all too often they have altered the radio in such a way that it no longer confines the signal to the particular channel it is set on and instead splatters it to adjacent channels and perhaps even out of the 11 meter wavelength altogether. It may be louder, but not in a good way.

Generally, it is best to use the radio as the factory designed it. Any added "performance" is often a change to the worse.

 

[TheSpaceMann]

I've never been in a radio shop myself since the only problem I have had with a radio was with a new one under warranty, and the factory sent me a new replacement.

However, I have read many times that people will ask a radio tech to increase the performance of their radio, as in, getting more communication range out of it and make it "louder ". Some techs, derisively called "Golden Screwdrivers" by some, are more than willing to modify the radio so that they can show you a higher wattage number on their instrument and tell you the extra power will get you more range, but all too often they have altered the radio in such a way that it no longer confines the signal to the particular channel it is set on and instead splatters it to adjacent channels and perhaps even out of the 11 meter wavelength altogether. It may be louder, but not in a good way.

Generally, it is best to use the radio as the factory designed it. Any added "performance" is often a change to the worse.

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