Leaving SWR meter inline with cb radio?

[Coalsmoke]

Any problems with doing this. I picked up an aftermarket one made by Diesel and it seems to be much more accurate than the Cobra built-in one, so I have kind of grown to like having the new meter working inline. According to the instructions that came with the meter I can do this, but I thought I'd get some second opinions.



TIA,

Stephan



Also, anyone use 10 codes on their cb? If I use 10 codes will anyone know what I'm talking about?

 

[mbaston]

I have always done this with HAM. There may be some loss but I don't think you would notice it.

 

[PRout]

Its no problem to leave it inline. The 1/10th db loss is not noticable.



The only thing that might happen is you accidently slam the needle if its on the wrong scale, and/or its more connections to possibly work loose, but its a good thing to be able to watch your vswr on the fly.



Bottom line - no biggie.

 

[Coalsmoke]

ok, thanks guys.

 

[skobylenski]

What 10 codes do you mean? There are different ones for public versus government use. Whatever you do, don't get caught using police 10 codes and such. For public use, about all I ever hear is 10-4 and "What's yer' 20?" Other than that it's all just talk.

 

[Coalsmoke]

I don't see how using police codes would be so horrible, unless you were trying to impersonate an officer?

 

[evldsl]

Rember to always cut ( use) the cable at 3' length to get the correct impedence between the radio and the antenna. Such as antenna 3'swr meter 3' cobra radio so you would have 3' of cable between the antenna and the meter then 3' of cable between the meter and the radio. You will probley need more then 3' between the units but make sure you cut the cable in 3' lengths. Such as antenna 9' of cable to swr meter 6' of cable to radio.

 

[Gary - K7GLD]

DUNNO about the precise length of connecting coax comes in - I'm FAR more interested in what the swr is right at the radio than I am at some other point in the system, so usually put the meter as close to the radio as possible...

 

[Chris N5CWM]

Re: 10 codes

Originally posted by Coalsmoke

. . anyone use 10 codes on their cb? If I use 10 codes will anyone know what I'm talking about?

I don't see why anyone would care if you used 10 codes.

The only way anyone would know what you were talking about would be if you used a standard form. There probably is no standard for CB. If you make up your own, and give a copy to whoever it is you're talking with, then of course no one will know what you're talking about.



If there is a "standard", then this must be it.



http://home.att.net/~wizardoz/cbmw/10codes.html



and



http://www.truebluedriver.org/cb_radio_10_codes.htm





http://www.cbland.8k.com/10_code.htm



are pretty similar.



Here is the

FCC's Rules regarding CB usage.



Here's the FCC's view of 10 codes.



_. . . _. ..... _. _. . _ _ _ _

 

[Coalsmoke]

Yup, there is a standard form. Easy to find, just wondering whether anyone actually still used them. As for the coax, good point. My system is running 18' main and the meter patch is 3'

 

[K5IP]

OK, from another HAM,

From an engineering standpoint, coax cable length is not important as long as your antenna represents a good 50 ohm load . All impedances along a well matched 50 ohm line are 50 ohms. Cutting a transmission line to specific lengths only becomes important if the antenna is not well matched. This is not usually a problem in CB operation since the bandwith is limited, and the antennas are usually quite good.

I'd cut where convient.

Roger

 

[Coalsmoke]

Well, it's all installed now, and I did run across the argument before that the multiples of 3' is not needed when your system is set up properly. I just went with it anyways, as a an extra potential safeguard. (Firestik's website addressed this and then also noted that most vehicle owners aren't going to want to drill a hole through the roof of their $30,000 vehicle to mount everything in 'optimal' positions). However, if I had to do it again and I knew how low my SWR levels would be, I would have cut out the extra 10' of cable instead of having to find a safe spot for it under the dash, and then bind it in a 14"+ skeen style gathering.

 

[K5IP]

What is your VSWR now?

Rog

 

[Coalsmoke]

It varies from 1:1. 1 to 1:1. 4 depending on whether its a higher or lower fequency. I've tried to tune it out but can't get much better and this is close enough for me.