| Author |
Message |
    
Jerry Bryant
| | Posted on Tuesday, October 02, 2001 - 2:28 pm: | 
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When running amps in the past I've always used antenna tuners rated for the power I was running to lower the slight increase in S.W.R. from the power increase. After recently helping install a bearfoot radio mobile setup in my friends' wifes' car, we used an old antenna tuner to reduce a slight mismatch with her 102" whip. On my base station and theirs we noticed approximately a four db increase in signal from what she usually gives us during her commute home from work, and there was a big difference in signal on the recieve end when I was riding shotgun with her in the car. I have for years used homemade inductors to tune slightly high S.W.R. and have had good results from ones bought at my local c.b.shop. I'm considering trying out one of those M.F.J. or Vectronics roller inductor tuners. Anyone elses experiences with tuners????????? J.C.B. |
Vernonott
| | Posted on Tuesday, October 02, 2001 - 4:10 pm: |
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Jerry : I am not educated enough to actually know how a tuner works ,but I have been told 100 times over the years that a antenna tuner does nothing but fool the radio. |
Jerry Bryant
| | Posted on Wednesday, October 03, 2001 - 1:40 pm: |
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I've heard this also Vernonott, but I would consider this a good thing if it fools the radio into putting out more power. |
doctor bleedover
| | Posted on Friday, October 05, 2001 - 12:55 pm: |
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antenna tuners make the radio "see" a better swr and therefore the radio may run better from a cooling standpoint for the finals.
when using the formula in the radio handbooks for effective radiated power you do not calculate the swr!!
gain of the antenna . losses in coax , all enter into effective radiated power.
if your swr is under a 2 to 1 ,let it go and don't worry about it. |
bruce
| | Posted on Saturday, October 06, 2001 - 1:28 am: |
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i use a mfj945 and it does very well rubbering my vetical on 17,20 and 15 meters but you can see that there is a drop in signal even with the " Match " being good when all else fails it works |
GRAYHOUND
| | Posted on Friday, October 19, 2001 - 9:12 am: |
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IF THERE WASN'T A GOOD REASON TO USE THEM ; WHY DO SO MANY HAMS USE THEM ?
I LOVE MINE !
ALSO , THERE ARE A "LOT" OF NEW HAM RIGS THAT HAVE AUTOMATIC TUNERS BUILT INTO THE RADIO !
FOOD FOR THOUGHT !!!
"GRAYHOUND" |
RM HARRIS
| | Posted on Sunday, November 04, 2001 - 11:44 am: |
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USUALLY when people use antenna tuners it is because they don't want to take the extra step for time sake.The extra effort is worth it when you have add on equipment. |
Gilbert E Edwards
| | Posted on Saturday, November 10, 2001 - 10:13 am: |
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SSB 2103 I am currently using a MFJ941E I have no problems with it. Gents I wouldn!t go anywhere without one. |
Hydro
| | Posted on Friday, November 16, 2001 - 1:46 am: |
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I'm going off the top of my head and not reading the books at this point. The ARRL has an awesome antenna book but can be confusing.
In short, a tuner next to your radio for the most part is changeing the feedline impedence at the radio(fooling your radio) but it is also tuning the antenna to a point ,hence the the difference in receive.
You want the tuner as close to the antenna as possible in order to tune the ANTENNA and not the feedline.
The best example I can think of is a miniture loop antenna. The capacitor is actually in the loop which makes it part of the antenna so when tuned the antenna is tuned and not the coax.
Hope this helps.
Joe |
