Hooked up a radio to a boomer 600 , amp off SWR 1.25 , with amp on SWR is showing RED zone . But, reports are coming back good & distance has not been compromised. What say guys??
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SWR any reason to worry??
- Thread starter Chainsawgang
- Start date
palomars are notorious for that, including the one I have for now. They say its from poor tuning in the amps. If your swr is fine with amp off, you are ok.
Thanks for the responses guys, I will check the SWR between the amp & radio tonight. It's has been a pretty good amp , nothing special but it gets out rather nicely. I will post back tomorrow; what kind of SWR reading would be considered OK ??
DTB Radio said:
good suggestion DTB. I did this a while back and it was much lower, it still jumped up a bit (like 1.5) but that was good for me.
While I don't agree with the use of amplifiers on CB, I can, however, tell you WHY most CB amps do this. This question gets asked all OVER web forums everywhere.. And it shows us just how sorry these things actually ARE! :shock: It is because of the CHEAP non-linear characteristics of them and the lack of filtering. The internal circuitry of these things not only amplifies 27 MHZ but several multiples of the fundamental frequency. Depending on the "ground floor" frequency which then is raised with IF circuits ( intermediate frequencies) and doubler circuits it might start out at..........I don't know; I'm guessing not having seen a particular schematic---------------8-9 MHZ (which is why many of them work down to 40 Meters). then the IF circuits, etc. raise the frequency up to 27 MHZ. Trouble is, because the things AREN'T filtered, it doesn't stop there. You might get multiplied spurs at 9 MHZ, 18 MHZ, 27 MHZ, 54 MHZ--who knows WHERE the thing will emit spurious garbage. And that's where you get the "mysterious" and "wild" SWR readings because the amp is seeing ALL those frequencies coming back to an antenna that is set for 27 MHZ. The SWR may be off the scale because it "sees" a spur emission at 9 MHZ and the antenna is good at 27 MHZ so that when you turn the amp OFF, and it's no longer emitting the other "frequencies", your SWR is normal.
A good Amateur amplifier HAS the filtering and is designed to work multiple bands, but also might not work for MARS because it lacks the filtering, or range. Anyway it's the same principle.
So now you know why the Feds don't like CB amps, why other radio services cringe at the mention of them, and hams often look down their noses at them!
73
CWM[/i]
A good Amateur amplifier HAS the filtering and is designed to work multiple bands, but also might not work for MARS because it lacks the filtering, or range. Anyway it's the same principle.
So now you know why the Feds don't like CB amps, why other radio services cringe at the mention of them, and hams often look down their noses at them!
73
CWM[/i]
Boomers are known for that. Chainsawgang, you might seem to like that amp but Boomers are the last thing i would wish on anyone unless it was a heck of a deal.
I like Boomers (surely better then nothing)I always liked there all the way around heat sinks , not the best amp on the planet but I had a few of them and never had any major problems that I could remember . I think on the both that I had , the low/med/hi switches would always lose the med setting so the amp would only have the hi and the low , no biggy. Never had any SWR problems with them at all. Now Texas Star's would be a different story.
(surely better then nothing)I always liked there all the way around heat sinks , not the best amp on the planet but I had a few of them and never had any major problems that I could remember . I think on the both that I had , the low/med/hi switches would always lose the med setting so the amp would only have the hi and the low , no biggy. Never had any SWR problems with them at all. Now Texas Star's would be a different story.Thanks everyone for all the responses, truthfully I agree w/ you on the Boomer they do not compare with my Messenger or Texas Stars for sure . But, as Switchkit said : it was dirt cheep & better thAN NUTHIN'! (BTW Switchkit , Your avatars with the different guitarists are cool) Now as promised I have done my checks & have the results:
A) SWR w/ a radio only 1.2
B) SWR w/ the boomer ; measured between boomer & antenna 1.1
Now as DTB suggested I coupled the SWR meter between the radio & the boomer. The readings are
C) w/ boomer off 2.3 with the
D) boomer on measured at all three power levels the SWR was in the red @ 3.0 plus.
Any ideas ??
The setup is a Galaxy radio .....3ft. jumper ... Boomer .....Wilson 5000 antenna. Thanks for your time.
p.s. Yes I DID RE-CALIBRATE the meter before every check.
A) SWR w/ a radio only 1.2
B) SWR w/ the boomer ; measured between boomer & antenna 1.1
Now as DTB suggested I coupled the SWR meter between the radio & the boomer. The readings are
C) w/ boomer off 2.3 with the
D) boomer on measured at all three power levels the SWR was in the red @ 3.0 plus.
Any ideas ??
The setup is a Galaxy radio .....3ft. jumper ... Boomer .....Wilson 5000 antenna. Thanks for your time.
p.s. Yes I DID RE-CALIBRATE the meter before every check.
With all that being said,,,, You should buy a ham amplifier that works between 10-12 meter and your all set :shock:
C W Morse said:While I don't agree with the use of amplifiers on CB, I can, however, tell you WHY most CB amps do this. This question gets asked all OVER web forums everywhere.. And it shows us just how sorry these things actually ARE! :shock: It is because of the CHEAP non-linear characteristics of them and the lack of filtering. The internal circuitry of these things not only amplifies 27 MHZ but several multiples of the fundamental frequency. Depending on the "ground floor" frequency which then is raised with IF circuits ( intermediate frequencies) and doubler circuits it might start out at..........I don't know; I'm guessing not having seen a particular schematic---------------8-9 MHZ (which is why many of them work down to 40 Meters). then the IF circuits, etc. raise the frequency up to 27 MHZ. Trouble is, because the things AREN'T filtered, it doesn't stop there. You might get multiplied spurs at 9 MHZ, 18 MHZ, 27 MHZ, 54 MHZ--who knows WHERE the thing will emit spurious garbage. And that's where you get the "mysterious" and "wild" SWR readings because the amp is seeing ALL those frequencies coming back to an antenna that is set for 27 MHZ. The SWR may be off the scale because it "sees" a spur emission at 9 MHZ and the antenna is good at 27 MHZ so that when you turn the amp OFF, and it's no longer emitting the other "frequencies", your SWR is normal.
A good Amateur amplifier HAS the filtering and is designed to work multiple bands, but also might not work for MARS because it lacks the filtering, or range. Anyway it's the same principle.
So now you know why the Feds don't like CB amps, why other radio services cringe at the mention of them, and hams often look down their noses at them!
73
CWM[/i]
I heard that Happy Hamer & CW Morse ! Without a doubt a good Ham amp is better built , I guess I shouldn't have put my meter on it . How does that old saying go ....what we don't know..............
got to say
C W Morse nailed it
i am not big on using anmps on any frequency
but especially all those splah box units that so often wind up on cb
C W Morse nailed it
i am not big on using anmps on any frequency
but especially all those splah box units that so often wind up on cb