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Message |
    
Freebird
Intermediate Member
Username: Freebird
Post Number: 438
Registered: 1-2003
| | Posted on Sunday, June 18, 2006 - 2:27 am: | 
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OK I have 2 low pass filters for my radios.one i just bought yesterday its a bencher YA-1 filter i bought off a friend cost new about 90 bucks.he other one is cheaper a workman low pass filter not sure what i paid for it maybe 25 bucks.on my meter with the bencher filter and my amp on i do 150 with a dead key on am and 175 sideband....with the cheaper workman filter the amp will do 200 am dead key and 225 watts sideband...my question is why is the low pass filter that is more money cutting down my wattage so much I dont get it? |
Bruce
Senior Member
Username: Bruce
Post Number: 3938
Registered: 9-2003
| | Posted on Sunday, June 18, 2006 - 8:54 am: |
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The belcher has a lower cutoff and higher atenuation of anything above cut off.
Drive your amp at 1/2 power and recheck see if they dont get closer in outputs ... |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2994
Registered: 7-2004
| | Posted on Sunday, June 18, 2006 - 10:59 am: |
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as bruce says....the better filter is removing the harmonics/trash that the cheap one is letting through |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1821
Registered: 9-2004
| | Posted on Sunday, June 18, 2006 - 11:10 pm: |
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i will say the same thing these guys said in a different way.
your radio is putting out a signal on 27mhz, and also some signal on 54mhz, and even a little on 108mhz.
the low pass filters job is to only let the 27 mhz signal pass.
your wattmeter is designed to read the wattage out at 27mhz.
if any signal at 54mhz, or 108mhz get into it, the wattmeter doesnt know what to do with it, and it shows up as increased wattage out on the meter, but in reality, thos watts are not on 27mhz, so they are not helping you get heard.
the good low pass filter is doing its job and showing you a more accurate representation of what is actually coming out of the amp wattage wise.
the workman filter is not doing its job very well, and is still letting some of the 54/108mhz signal through, which is showing up as more watts out.
the bencher is giving you a truer reading.
matt |
Dale
Intermediate Member
Username: Dale
Post Number: 497
Registered: 12-2002
| | Posted on Monday, June 19, 2006 - 1:44 pm: |
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very well said i bought a workman filter it didnt work at all.i tried a fcc type radio 4watts rms and 12pep still no luck everything grounded ,with the stock amc cirits in plaxce the way they should be |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1457
Registered: 1-2005
| | Posted on Wednesday, June 21, 2006 - 1:03 pm: |
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Freebird, I agree with the other guys also. You will still get out on transmit the same but now you will have cleaner better sounding audio and your amp will work much better and run cooler since it does not have the unwanted harmonics to amplify as well. So many cbers would freak out if they knew how many watts they actually had. |
