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I don't know which agencies can legally license technicians now. Back when I earned my GROL, it was the only game in town...

Beetle, I guess it really depends on how we define the current flow inside the coax. In order for the RF components to not "leak" from within the inside of coax the shield, the shield must be at least several RF skin depths thick and then the shield will contain any magnetic field generated...

It used to be a 1st or 2nd Class, and/or General, Radiotelephone Operator License issued by the FCC. Now the FCC allows a few other testing agencies to issue licenses that meet their requirements as well.

That is a good question and there are many factors to consider. First, have you even determined if the noise is radiated or conducted? If the noise is radiated, maybe a change in location will generate less noise into the sensor and/or its wiring. Maybe the antenna is not tuned...

Any antenna that requires a balanced feedline, such as a dipole, though a balun could be used. Also, I don't buy into the whole current flow on the inside of coax versus the outside of coax. If current is flowing in the shield, it is flowing in the entire shield (inside and outside) since...

Are you asking about a common mode coaxial choke? If so, it may mask the symptoms but it doesn't fix the problem. Common mode currents are currents that are undesired when using an unbalanced antenna system such as a monopole whip. Ideally all of the current is radiated into free space when...

RF Chokes are nothing more than an inductor. An RF Choke blocks an AC signal while allowing DC to pass. RF Chokes are typically used on the DC supply of the device affected by noise. Most times an RF Choke is placed in series with the power lead with a capacitor placed across the power lead...

Because when you transmit, the RF signal is being coupled into the speakers wiring, which comes out the speaker and into the microphone, and then back into the CB to complete a loop. This is called positive feedback and is the principle of oscillators, hence the high frequency squeel you are...

Since the elements would appear to be very close together when installed, I would say yes, but I am only guessing. It looks very similar to the VHF DF's used on some of the CG small boats.

I'm guessing its a phased array that is probably used for direction finding.

QRN thanks for explaining the differences between the amature rules for each country. I am not a ham operator, though I do have a GROL, and my CB is normally only used for trail communications, so 4 watts works for me. :)

ss8541, I was just making a general statement and thanks for posting the specifications. Ken

Yeah, I should have said FM typically requires more BW. When using FM and a high modulation index, the frequency spread is quite wide and since the power is the same for all frequencies, there is a lot more energy generated at the ends of the channel allocated BW. All of my experience with FM...

Since the modulation occurs by changing the frequency, and not changing amplitude, the dead-key and modulated signal will contain the same power. You can probably adjust the transmitters power, but it should not change with modulation. As a side note, FM is allocated a lot more BW, so sending...

Nice JK flop... Time to upgrade a few parts. :twisted:

Yes, or you could also add an in-line LC filter.

Warby, a BALUN is used to match a balanced transmission line to an unbalanced line. If your antenna system is balanced, a BALUN will work and there are numerous designs already calculated with instructions that will help. However if the antenna is not balanced, then you would need to know...

For a mismatch between 75 Ohms and 50 Ohms, the VSWR will be 1.5:1 (75/50) assuming the ohms are purely resistive and not reactive.

If there was no noise when the antenna was disconnected, then the noise is radiated. This means the fan noise is electro-magnetic in nature so unless you can shield motor better, you will probably have to move the antenna to get it out of the noise field. Filtering the power leads will...

First see if the noise is radiated or conducted. Disconnect the antenna and see if you still hear the noise. If you do, it is conducted and filtering the radio's power leads, and or fan power leads, and or moving the CB's power leads should help. If the noise goes away, then moving the...